Chapter 46: Pelvic Ring Fractures

Animesh Agarwal

Chapter Outline

Introduction to Pelvic Ring Fractures

The treatment of pelvic ring fractures continues to evolve in an attempt to improve outcomes for these patients. The treatment continues to be based on the fundamental understanding of pelvic anatomy. Although many stable fractures can be managed nonoperatively, unstable fractures continue to require surgical intervention. New techniques continue to be developed to improve on older methods. With continued improvements in automotive safety features as well as emergency medical services (EMS) response and transport, many more multiple trauma patients are surviving and presenting to trauma centers requiring pelvic ring fracture management. A recent epidemiologic study377 over a 10-year period showed that pelvic ring fractures can affect all ages but the predominant age group was in the 18 to 44 age group with an overall mean age of 45. The geriatric population comprises about 22% of the overall number. Men are affected slightly more than women (56% vs. 44%). The incidence of pelvic ring fractures was reported to be 0.82 per 100,000 people. In addition, with the increasing age of our population and the increasing number of “geriatric” trauma patients, pelvic fixation in osteopenic bone is a concern. Although morbidity and mortality related to pelvic ring fractures continue to be problems, it is increasingly accepted that anatomic reduction and stabilization of displaced injuries can improve outcome.61,70,132,342 This association between reduction and outcome is well known from early reports on the management of pelvic ring fractures.70,132,177,195,342 Hemodynamic instability in patients with pelvic ring fracture is a concern, and more aggressive means of addressing pelvic bleeding such as retroperitoneal packing and continued use of angiography are being employed. These aggressive resuscitative measures can help decrease mortality.129,230,271,336 
An understanding of the anatomy of the pelvis is key to the management and treatment of pelvic injuries. The pelvis should be viewed as a ring structure. Therefore, any break in this ring can lead to stability issues, which may require operative intervention. Surgical intervention may be needed for fracture treatment and/or hemodynamic concerns. Fracture classifications for pelvic ring fractures are based on mechanism of injury or stability, with overlap between classifications. However, stability of the pelvic ring is the fundamental concept that drives treatment decisions. Hemodynamic instability may be an extension of fracture instability, with unstable fracture patterns associated with a higher incidence of bleeding. 
The pelvis is divided into anterior and posterior parts, and injuries to these respective areas will dictate treatment. Generally, a single break in the ring does not lead to instability, whereas for unstable injuries there are always injuries to at least two areas of the pelvis. An account of the accident in which the patients sustained a pelvic ring fracture can help determine the mechanism of injury and help classify the pattern. The Young and Burgess classification categorizes fracture patterns based on such mechanisms into three anterior-posterior injuries (APCI, II, III), three lateral compression injuries (LCI, II, III), vertical shear (VS), and combined mechanism (CM). Most importantly, this classification can help the trauma surgeon to predict associated injuries.60,72 
The morbidity and mortality accompanying pelvic ring fractures has been well documented since the early 1970s. At that time, some pelvic ring disruptions were treated with skeletal traction and pelvic slings to prevent excessive cephalad migration of the hemipelvis.343 In their series of publications, Slatis and Huittinen, documented a high morbidity and mortality associated with vertically displaced unstable pelvic ring injuries. The pattern of the posterior lesion (fracture versus dislocation) and the final position of healing determined pain and functional outcome. Their patient group had a mortality rate of 7%, compared with 18% in reports of other large series of patients published during the same period.178,261 Other reports of vertically unstable pelvic ring fractures treated nonoperatively documented a high incidence of poor functional outcome and chronic pain in those patients.132,144,169,189,296 These poor results generated interest in and an evolution of operative management of unstable injuries over the last several decades. 
Subsequent to these studies, external fixation came into practice in the management of vertically unstable fractures to improve late morbidity and mortality.267,312 Trauma management of the multiply injured patient, especially with respect to the musculoskeletal system and specifically pelvic ring fracture management, improved throughout the next several decades. Early stabilization of long bone fractures was stressed. The use of external fixators for treating patients with pelvic ring fractures continued to increase. Initially, surgical stabilization came in the form of an anteriorly placed external fixator used alone. These anterior-only constructs were found to be ineffective in controlling both the vertical and posterior displacement of the posterior aspect of the ring.150,151 However, certain anterior–posterior compression or lateral compression injuries could be managed sufficiently by external fixation alone.168,369 Subsequent clinical outcome studies regarding the use of external fixators for posteriorly unstable injuries showed the same poor results as with nonoperative management. There was some suggestion that traction may have been more successful at treating vertically unstable injuries.189 
Over time, there has been a better understanding of the biomechanics involved in the management of severe unstable pelvic ring injuries52,112,287,305 Surgical techniques have improved, and studies showed improved outcomes with anatomic reduction of the posterior ring.70,110,169 The addition of anterior fixation, in the form of either an external fixator or symphyseal plate, has increased the biomechanical stability in cases of vertical instability.115,287,328 Early operative stabilization allows mobilization of the patient and improved short-term patient outcomes.110,276 This in turn has led to newer internal stabilization devices/techniques, such as iliosacral screw fixation, lumbopelvic fixation, and internal pelvic fixators.294,295,305,355 Although anterior external fixators have their place, symphyseal plates avoid the pin-tract complications seen and improve biomechanics and clinical outcome.287,288,328,360 
Treatment algorithms have been created to reduce the significant morbidity and mortality associated with these severe pelvic injuries and to improve functional outcomes. Unfortunately, however, the mortality of many multiply injured trauma patients with pelvic ring fractures is related not to the pelvic ring fracture but to the associated head injury, chest injury, or abdominal injury.5 Ongoing blood loss can be a significant contributor to mortality, especially in the unstable pelvic ring injury.72 It is important to note that a multidisciplinary approach to the management of these patients including involvement of the orthopedic traumatologist has been shown to improve patient survival.16 We hope to provide orthopaedic surgeons with an understanding of the current management and treatment of pelvic ring injuries. 

Principles of Management for Pelvic Ring Fracures

Mechanism of Injury for Pelvic Ring Fracture

The majority of pelvic ring fractures are a result of a high-energy injury, although many elderly patients may sustain such injuries from a fall from standing height. Motorcycle accidents and motor vehicle pedestrian accidents are the most common mechanisms, although falls, motor vehicle collisions, equestrian accidents, and crush injuries also occur.167 Because of the survival of more trauma patients and subsequent arrival at trauma centers, there is an increase in the incidence of pelvic ring fractures occurring from high-speed motor vehicle collisions that require treatment65,139,265 Despite advances in air bag technology and other state-of-the-art safety measures in modern motor vehicles, side impact continues to be a major risk factor for pelvic ring fracture mortality and morbidity, as does vehicle size mismatch.281 In addition, these patients present with associated bony, visceral, and soft tissue injuries. These multiply injured patients with pelvic ring fractures have morbidity and mortality rates that range from 10% to 50%.109,178,211,261,267,274 Elucidation of the mechanism of injury has led to the development of a classification scheme that has provided a better understanding of the associated injuries seen with pelvic ring fractures. The Young and Burgess classification (described in greater detail later) was based on the mechanism of injury, and specifically the direction of force applied to the pelvis during injury. These investigators described four groups of injuries: Anterior–posterior compression (APC), lateral compression (LC), vertical shear (VS), and combined mechanism (CM). When looking at mortality and pelvic ring fractures alone, the overall mortality for APC injuries is approximately 20%, whereas LC injuries are about 6.6%. In the series by Burgess et al.,33 the pelvic ring fracture was the primary cause of death in only 2 of the 14 deaths, but pelvic ring fracture contributed or was related to death in all 14. The major cause of death in the LC fracture was head injury. The APC deaths were secondary to both the visceral and pelvic injuries. 

Associated Injuries with Pelvic Ring Fractures

Many patients with pelvic ring fractures have multisystem injury. These patients will often have associated head, thoracic, and abdominal injuries, in addition to other extremity injuries. Previous studies16,65 have indicated that the most frequently encountered injuries associated with pelvic ring fractures in general are chest injuries (63%), long bone fractures (50%), head injury (40%), solid organ injury (40%), and spinal fracture (25%). Intestinal injuries are also encountered in up to 14% of patients with concomitant pelvic ring fractures.65 
It is important to understand the mechanism of injury and the resultant pelvic injury pattern, which can help to elucidate associated injuries. Specifically, in patients with APC injuries there is an eightfold increased incidence in thoracic aorta injuries when compared to patients with blunt trauma without pelvic ring fracture.227 APC type III injuries are associated with a high rate of circulatory shock (67%) and greater blood loss and transfusion requirements than other injury patterns. In additionally, in patients who are hemodynamically unstable there is a higher incidence of acute respiratory distress syndrome (ARDS) (18.5%), sepsis (59%), and death (37%). Lateral compression injuries tend to be associated with a high incidence of head injury (50%). The most severe, LC type III, which can occur from a rollover mechanism, is associated with a 20% risk of bowel injury, 40% incidence of concomitant lower extremity fracture, and 60% presence of a retroperitoneal hematoma. Vertical shear injuries have a high risk of hypovolemic shock (63%), mortality (25%), head injury (56.2%), lung injury (23%), and splenic injury (25%).60 Patients with pelvic ring fracture require a systematic well-organized multidisciplinary approach to effectively and efficiently manage the multiple injuries that are frequently encountered. 

Genitourinary Tract Injuries

Bladder and urethral injuries occur in 6% to 15% of pelvic ring injuries depending on the severity of the pelvic ring fracture.6,78,80,82,232 Male patients have a higher incidence of urethral injury compared to female patients.6,78,193,243 The female urethra is short and adjacent to the vagina, which protects it from injury by the pelvic ring fracture.39,221 In addition, the vagina has a remarkably low incidence of injury, ranging from 0% to 5%.222 The male urethra is divided into anterior and posterior portions, with the latter being more commonly injured from shearing forces rather than by direct laceration from bony fragments.47,250 In posterior urethral injuries, there is a 10% to 20% associated incidence of bladder rupture.36 
Because of its location behind the symphysis pubis, the bladder can be injured easily; extraperitoneal (EPBR) bladder rupture is common. In this type of injury, the urine may communicate with the pelvis. An intraperitoneal (IPBR) bladder rupture, which is often caused by compression on the distended bladder resulting in rupture of the dome, communicates with the peritoneal cavity but will not contaminate the pelvis.46 Bladder injuries occur in up to 10% of pelvic ring fractures, with approximately 60% EPBR, 30% IPBR, and 10% both.6,40,41,78,215 Because the amount of force required to rupture hollow structures, such as the bladder, is so high, the associated mortality has been reported anywhere from 22% to 34%.40,179 
The majority of patients with a urologic injury will have gross hematuria, although a small subset of patients may have only the finding of >30 to 50 red blood cells noted on a urinalysis, which is indicative of an injury.38,78,83,130 All these patients should have a cystogram.85,259 In the male patient, a dynamic retrograde urethrogram (RUG) is the best study to evaluate for a urethral injury (Fig. 46-1). A Foley catheter is inserted into the penile urethra and the balloon is inflated with 1 to 2 mL of saline; 25 mL of water-soluble contrast material is then instilled. An anteroposterior (AP) view of the pelvis or a 30- to 45-degree oblique view is obtained under fluoroscopy, if possible. Lack of contrast in the bladder usually indicates a urethral disruption, although the bladder may still fill with contrast (Fig. 46-2). After the RUG is performed, if the urethra is not injured, an attempt is made to pass the catheter into the bladder and a cystogram (either plain radiograph or computerized tomography [CT] scan) is performed by instilling an additional 300 to 400 mL of water-soluble contrast into the bladder.78,240 The radiographic appearance of a bladder rupture is demonstrated in Figure 46-3A. Many centers prefer to use a CT cystogram (Fig. 46-3B–D) to diagnose bladder ruptures (Fig. 46-3A–D). 
Figure 46-1
Normal retrograde urethrogram and the appearance of intact bladder.
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Figure 46-2
Proximal urethral disruption seen by contrast extravasation over the perineum; bladder is intact.
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Figure 46-3
 
A: Contrast extravasation in obese female patient indicating bladder rupture. B–D: Due to size of patient and poor plain imaging, suspected bladder rupture confirmed with CT cystogram.
A: Contrast extravasation in obese female patient indicating bladder rupture. B–D: Due to size of patient and poor plain imaging, suspected bladder rupture confirmed with CT cystogram.
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Figure 46-3
A: Contrast extravasation in obese female patient indicating bladder rupture. B–D: Due to size of patient and poor plain imaging, suspected bladder rupture confirmed with CT cystogram.
A: Contrast extravasation in obese female patient indicating bladder rupture. B–D: Due to size of patient and poor plain imaging, suspected bladder rupture confirmed with CT cystogram.
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Once a bladder or urethral injury has been diagnosed, consultation by the urologic service is needed to manage the injuries. Clear communication between the orthopaedic trauma service and the urologic service is recommended to ensure that urologic treatment does not prevent or hinder potential orthopaedic interventions for the pelvic ring injury.232 Intraperitoneal bladder ruptures are treated with exploratory laparotomy and suture repair, and must be drained by Foley or suprapubic catheter placed well out of the way of sites of potential anterior incisions (Fig. 46-4). If anterior fixation is required, it can be accomplished in the same setting, or an anterior external fixator can be placed if the patterns warrant it. An extraperitoneal bladder rupture can be treated nonoperatively with Foley catheter drainage and antibiotic prophylaxis.159,232 However, in situations for which an open reduction and internal fixation (ORIF) of the anterior pelvis is necessary, both bladder repair and ORIF of the anterior pelvic ring can be performed at the same surgical setting through the same incision. If an extraperitoneal bladder injury is not repaired or repair is contraindicated, then strong consideration should be given to external fixation as the definitive treatment for the anterior pelvic injury, since internal hardware may be contaminated by urine.80 Nonoperative management of extraperitoneal bladder ruptures has a reported complication rate of up to 26% versus 0% in operatively managed bladder ruptures.160 
Figure 46-4
Incorrect placement of a suprapubic catheter that is too low and in the field of a Pfannenstiel incision.
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The treatment of urethral tears in male patients is controversial and ranges from endoscopic realignment to acute suprapubic drainage followed by delayed reconstruction.158,215 Advocates of realignment procedures note decreased stricture rates from 14% to 45% versus almost 100% in delayed reconstructions.80 In either case, the bladder must be reliably drained to avoid complications from extravasation of urine in the face of internal anterior ring fixation. 

Open Pelvic Ring Fractures and Gastrointestinal Injuries

With significant trauma and high-energy injuries, pelvic ring fracture fragments can penetrate soft tissue, resulting in direct communication with the external environment in an open fracture in up to 5% of patients with a pelvic ring fracture.27,256 In addition, the bony fragments may cause direct damage when in contact with the visceral cavity. Furthermore, open fractures may occur from the tensile forces in APC type injury in the midline. These open pelvic ring fractures are often contiguous with the vagina or rectum resulting in contamination. This can significantly increase the number of complications including osteomyelitis, deep pelvic infection, long-term disability, and mortality. Jones et al.141,274 reported on a classification of open pelvic ring fractures: Class 1, 2, or 3. Class 1 fractures were open pelvic ring fractures in which the pelvic ring is stable. In class 2 fractures, the pelvic ring is rotationally or vertically unstable, and there is no rectal or perineal wound. In class 3 open pelvic ring fractures, the ring is rotationally or vertically unstable, and a rectal or perineal wound with potential for fecal contamination is present. Many of these class 3 patients developed sepsis with a 44% mortality rate. Clinical examination of patients with a pelvic ring fracture should include a careful genitourinary examination to ensure that no occult open fracture has been missed. A digital rectal examination and a vaginal examination should be performed in female patients. Open wounds may occur anywhere along the course of the iliac crest or through the perineum (Fig. 46-5). Open pelvic ring fractures with fecal contamination have been associated with a high mortality rate of up to 50%;242,256 therefore, early recognition and appropriate therapeutic interventions are required.119 
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Figure 46-5
CT scan showing paralabial open wound (arrow).
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Such injuries, which damage the anal sphincter or the gastrointestinal tract may require diverting colostomy and emergent irrigation and debridement of the fracture.27,236 Any potential for fecal contamination of the fracture site or the open wound should be addressed with fecal diversion and distal washout in an effort to prevent infection.264,373 The actual placement of the colostomy should be as high as feasible and as far as possible from any possible surgical approaches for pelvic ring fracture fixation. Ideally, to maximize outcome and minimize sepsis and death, the diverting colostomy should be performed within the first 6 to 8 hours after injury.373 Discussion of this between the trauma surgeon and the orthopaedic traumatologist is in the best interest of the patient. 
In cases where fecal contamination is not a concern, the fracture can be treated with regular irrigation and debridement of the open fracture site and handling of the soft tissues as indicated along with intravenous antibiotics. Similarly, an open fracture communicating with the vagina can be managed with serial irrigation and debridement, packing, and eventual closure of the vaginal wound over a drain when clean. This may require assistance of the gynecologic service and pelvic stabilization to avoid reinjury. 

Signs, Symptoms, and Initial Management of Pelvic Ring Fractures

Initial Assessment

Multiply injured patients require a thorough evaluation, including a careful history regarding the mechanism of injury. Prehospital personnel can provide valuable information. Taking the mechanism of injury into account, the patient presentation, and physical examination a suspicion for an occult pelvic ring fracture may be raised. Prehospital management of multiply injured patients includes immobilization of the spine with the use of cervical collars and back boards and various ready-made splints for extremity injuries. Airway protection as needed and appropriate circulatory support with intravenous fluids continue to be a main goal of prehospital transport with expedient transport to the nearest trauma center. In the last decade, as an adjunct to resuscitative measures, the use of external pelvic compression devices (binders; sheets) has become increasingly popular in the prehospital setting.362 Various emergency department algorithms and prehospital transport protocols now include the early use of such binders and can improve patient survival.32,58,196 Such protocols vary from institution to institution based on available resources and expertise; however, it is important to have a protocol in place that is customized to each trauma center. In an effort to increase the awareness of the importance of pelvic ring fracture management in the treatment of the multiply injured patient, the Orthopaedic Trauma Association (OTA) has proposed a generic pelvic algorithm that can be posted in the emergency department (Fig. 46-6; www.ota.org). 
Figure 46-6
OTA poster for emergency department to highlight initial pelvic fracture management.
 
(Reprinted with permission from: Orthopaedic Trauma Association. Emergency Department Guide for Acute Management of Pelvic & Acetabular Fractures. The Newsletter of the Orthopaedic Trauma Association, 2012 Fall.)
(Reprinted with permission from: Orthopaedic Trauma Association. Emergency Department Guide for Acute Management of Pelvic & Acetabular Fractures. The Newsletter of the Orthopaedic Trauma Association, 2012 Fall.)
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Figure 46-6
OTA poster for emergency department to highlight initial pelvic fracture management.
(Reprinted with permission from: Orthopaedic Trauma Association. Emergency Department Guide for Acute Management of Pelvic & Acetabular Fractures. The Newsletter of the Orthopaedic Trauma Association, 2012 Fall.)
(Reprinted with permission from: Orthopaedic Trauma Association. Emergency Department Guide for Acute Management of Pelvic & Acetabular Fractures. The Newsletter of the Orthopaedic Trauma Association, 2012 Fall.)
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Initial management of the trauma patient should be dictated by Advanced Trauma Life Support (ATLS) protocols.3,209 Multiply injured patients require a multidisciplinary team approach to optimize management.163 Patients are at risk for intracranial, chest, abdominal, soft tissue, pelvic, and extremity hemorrhage. The ATLS protocol provides a systematic and organized approach to management of these critically injured patients.3 Initial evaluation by the trauma team during the primary survey begins with airway evaluation and management, ensuring that the patient is adequately moving air as well as oxygenating appropriately. In all cases, but especially in the hemodynamically unstable patient (systolic blood pressure [SBP] <90 mm Hg), sources of hemorrhage must be identified emergently. Traumatic wounds with obvious bleeding should have dressings applied to minimize ongoing blood loss, with appropriate surgical management to follow. Careful monitoring of patients throughout their emergency department trauma resuscitation is vital. Determination of the appropriate studies or interventions to determine internal bleeding such a CT scan, focused assessment with sonography for trauma (FAST), or diagnostic peritoneal lavage (DPL) is often surgeon and institution dependent as well as dependent on the patient’s initial presentation.214 Patients who present initially with hemodynamic stability can quickly decompensate. Thus patients with multiple injuries require close observation in the intensive care unit for the first 24 to 48 hours. 
Initial radiographic studies of the chest, abdomen, and pelvis continue to be a mainstay in the routine initial screening evaluation of trauma patients. Further evaluation includes CT scan of the chest, abdomen, and pelvis. This allows for the evaluation for free fluid within the peritoneal and preperitoneal cavities as well as for organ injury and pelvic ring fracture anatomy. Patients who present with hemodynamic instability and have persistent hypotension despite adequate attempts at resuscitation—which include crystalloid, colloid, and blood transfusions—often require emergent exploratory laparotomy to evaluate for abdominal hemorrhage. 
Over the last several years there has been increased use of FAST. There has been some controversy as to its reliability due to lower sensitivity, negative predictive value, and significant operator variability. Early reports did not support its use as a substitute for either DPL or screening CT scan.116,154,352 Serial FAST examinations may increase sensitivity but are not practical in an unstable patient, and thus the DPL can be a valuable diagnostic tool for these hemodynamically unstable patients.42 The FAST, however, is becoming increasingly used in all patients followed by the operating room or angio in the unstable patient. However, the new Advanced Trauma Life Support, Ninth Edition, compendium of changes, which was recently released, now includes FAST as a skill station.4 It is recommended that either DPL or FAST be taught during a surgical skill station as a way to evaluate the abdomen as a source of hemorrhage. Many centers across the United States have already utilized FAST as part of the primary survey. The advantages of FAST include its noninvasive sonographic evaluation, lack of radiation exposure to patient, and its ease-of-use and availability for trauma surgeons as well as emergency medicine physicians. 
The patient with a pelvic ring fracture has sustained the injury in a high-energy impact, and these patients often have associated intra-abdominal, intrathoracic, or intracranial injuries in addition to other fractures. In the setting of an unstable pelvic ring fracture, one must not overlook the abdomen and chest as other potential life-threatening sources of hemorrhage. The decision to explore these cavities for bleeding sources needs to be made early using diagnostic studies or clinical findings; this is crucial to lower the mortality in this group of multiply injured patients. It has been suggested that either DPL or FAST be performed in hemodynamically unstable patients within 30 minutes of arrival to the emergency department.129 Although numerous diagnostic studies are available to evaluate these patients, ongoing hypotension, hemorrhage from a chest tube, and acute abdomen are indications for immediate surgical intervention. The decision to proceed with thoracotomy or laparotomy should still largely be based on the clinical presentation. Constant communication between the trauma team and the orthopaedic trauma service is paramount to provide efficient care. Often procedures between services can be coordinated, such as plating of the symphysis or pelvic packing in conjunction with laparotomy. Urologic intervention can occur concomitantly as well. However, it is important to remember that life-saving procedures and the overall condition of the patient are priority. Damage control surgery may take precedence, and subspecialty procedures should be delayed until the patient is fully resuscitated in the intensive care unit. 
If the patient does not require emergency surgical exploration and remains stable, or no clear source for the patient’s hypotension can be found, one can carefully proceed with the secondary survey while providing fluid resuscitation. Continual reassessment of the patient, especially the ABCs (airway, breathing, circulation), should be occurring. During the secondary survey, other injuries should be identified, especially those that may contribute to ongoing blood loss, which may also push the stable patient over the edge and into shock. If the CT scans have ruled out the chest and abdomen as the source of hemorrhage, persistent blood loss and hypotension are considered pelvic in origin. A finding of a pelvic hematoma >500 cm3 in size has been shown to have a 4.8 times increased risk of arterial injury and need for angiography.17,18,58 

Physical Examination

Patients may present with clinical signs suggestive of injury. VS injuries may present with lower extremity shortening and external rotation of the affected side. Unstable lateral compression injuries may have an internal rotation deformity of the lower extremity. APCs injuries often present with scrotal edema in the male trauma patient. A palpable hematoma over the perineum (Destot sign), above the inguinal ligament, or the proximal thigh may be indicative of a pelvic ring fracture with concomitant bleeding. Flank ecchymosis, or the Grey Turner sign, is indicative of retroperitoneal hemorrhage. Visual inspection and examination can lead to the diagnosis in many instances. In the conscious patient who can cooperate with a physical examination, the examination can yield 90% sensitivity in the diagnosis of a pelvic ring fracture.111 Careful examination of the patient with a pelvic ring fracture should be undertaken to include neurovascular assessment of the lower extremities, inspection of the skin to rule out open wounds, examination of the perineum for ecchymosis or frank blood, and palpation of the soft tissues to assess for fluctuant areas indicating potential degloving (Morel-Lavallee) injuries. Possible clinical findings in the patient with a pelvic ring fracture are listed in Table 46-1. Blood from the rectum or urethra often is indicative of an underlying injury, whereas in the nonmenopausal female, bleeding may be indicative of menses. However, in the female patient with a pelvic ring fracture a vaginal examination is warranted to rule out mucosal tears. Obstetrics and gynecology service should be asked to evaluate these patients, and communicating injuries may require dual management for the open and contaminated pelvic ring fracture. Rectal examination with frank blood may indicate a communication with the gastrointestinal tract, which requires colostomy. A high prostate on rectal examination may indicate a urethral tear. Urology should be consulted in such cases. 
 
Table 46-1
Pelvic Ring Fracture Clinical Examination
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Table 46-1
Pelvic Ring Fracture Clinical Examination
Open wounds of the groin, buttock, or perineum
Blood at the urethral meatus
Blood in or around the rectum
Pelvic, flank, or perineal contusions, ecchymoses, or abrasions
Blood out of the vagina (rule out laceration vs. menses)
Neurologic deficit involving the lumbosacral plexus
Leg length inequality
High-riding prostate (urethral injury)
Abnormal pelvic motion on anteroposterior or lateral compression of the anterior iliac spines and iliac crests
External or internal rotation deformity of the hemipelvis
Scrotal edema
Pain on palpation of posterior pelvis
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Gross instability of the pelvis can often be detected by direct manual compression and manipulation. Subtle instability is often difficult to detect. However, any manipulative attempts should be done only once, as this can elicit pain and be extremely uncomfortable for the patient. Furthermore, repetitive manipulation can dislodge clots and cause bleeding. Anteroposterior or internal compression should be applied directly to the iliac wings. Instability can be detected with posterior displacement or rotation of the hemipelvis. In addition, direct posterior pelvic palpation has been found to have high specificity and sensitivity in detecting posterior pathology in the awake and alert patient and has been suggested as a way to identify patients who may not need CT scan.194 At present, however, CT scanning remains an integral part of the clinical evaluation and management of the patient with pelvic ring fracture. In additionally, with modern imaging, direct manipulation of the pelvis is not always necessary as it causes pain and is of limited value in known injuries. 
Given the proximity of the lumbosacral plexus to the pelvis, it is crucial to obtain an accurate neurologic examination. Bilateral functional motor testing of the lower extremities (Table 46-2) should be performed in all trauma patients. Unfortunately, many trauma patients are intubated or sedated, making the examination impossible. Despite the variable mental status, some information can be gathered from the physical examination. When performing the rectal examination, rectal tone and the bulbocavernosus reflex can be assessed to rule out associated spinal cord injury. In the female patient, the bulbocavernosus reflex can be elicited by gently tugging on the Foley catheter. In the awake, cooperative patient, peripheral nerve examination is possible primarily for distal motor groups in the lower leg. Extra attention should be paid to testing the L5 and S1 nerve roots due to their frequent involvement in sacral fractures. The L5 nerve root lies on the sacral ala. The sacral nerve roots can be injured in transforaminal sacral fractures. Perineal sensation should be tested to evaluate the lower sacral nerve roots. Proximal muscle testing can be limited secondary to pain associated with the pelvic ring fracture, although simple contraction of muscle groups can be assessed and documented. Documentation of neurologic deficits or the inability to test for such deficits is warranted for medicolegal purposes as well. 
 
Table 46-2
Lower Extremity Motor Testing
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Table 46-2
Lower Extremity Motor Testing
L1–2: Hip flexors
L3–4: Quadriceps/knee extension
L4–5: Ankle and toe dorsiflexion
S1: Ankle plantarflexion
S2–3: Toe plantarflexion
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Diagnosis and Management of Pelvic Bleeding

Orthopaedic intervention depends on the stability of the fracture pattern as well as the stability of the patient. The patient with persistent hemodynamic instability warrants prompt diagnosis as to the etiology and appropriate treatment. Massive transfusion protocols and the need for immediate uncrossed-matched blood may be needed for appropriate resuscitation prior to orthopaedic interventions. These protocols are in place at all trauma centers and typically are utilized only as a last resort. It has been shown that patients with pelvic ring fractures who are hemodynamically stable on presentation have a mortality rate of 3%, compared with a mortality rate of 38% for patients who are hypotensive on presentation.218 The majority of deaths directly related to pelvic ring fractures are caused by arterial and venous disruptions with resultant hemorrhage.252 These vessels are intimately associated with and supported by the ligamentous structures that stabilize the pelvic ring (Fig. 46-7). Although venous structures have been classically considered the most frequent source of bleeding,138 this can be controlled with tamponade from increased tissue pressure within the retroperitoneal space. Unfortunately, a considerable amount of blood can be lost within the large pelvic cavity and the retroperitoneal space, even after closure of open-book–type injuries.117 If concomitant arterial bleeding is present, the tamponade of the retroperitoneal tissues can be overwhelmed. Mortality in patients with pelvic ring fracture secondary to pelvic hemorrhage usually results from uncontrolled bleeding from single or multiple arterial lacerations.17 Branches of the internal iliac system, most commonly the superior gluteal and pudendal arteries, are the usual sources.71 Contrast extravasation (CE) on CT is a sign of arterial bleeding that requires angiography,17,18,26,201,326 and recent improvements with the advent of the 64-slice multidetector CT scan has been shown to improve the overall accuracy in identifying arterial pelvic bleeding by identifying CE.210 Because of the evidence of CE as a strong predictor of arterial bleeding, the Eastern Association for the Surgery of Trauma (EAST) guidelines gave a Level I recommendation for the use of pelvic angiography and embolization regardless of hemodynamic status based on a positive finding of CE on CT scan.58 
Figure 46-7
Schematic drawing showing vascular structures intimate with ligamentous structures of the pelvis.
 
(Primal pictures 3D software utilized to create image; Copyright Primal Pictures 3D).
(Primal pictures 3D software utilized to create image; Copyright Primal Pictures 3D).
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Figure 46-7
Schematic drawing showing vascular structures intimate with ligamentous structures of the pelvis.
(Primal pictures 3D software utilized to create image; Copyright Primal Pictures 3D).
(Primal pictures 3D software utilized to create image; Copyright Primal Pictures 3D).
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As described earlier, patients with pelvic injuries should be aggressively resuscitated and the causes of hypotension identified expeditiously. The bleeding fracture edges may contribute to the blood loss, but their clinical contribution to decreases in hematocrit and blood pressure has been questioned.74 Recognition of the pelvic ring fracture pattern can help guide appropriate diagnostic studies toward the more likely source of bleeding. In general, stable LC injuries are not associated with major pelvic bleeding as seen in APC or VS injuries. Early identification of the pelvic ring fracture pattern can aid in the resuscitation of the patient, since some injuries are amenable to quick stabilization of the injury, which can decrease ongoing blood loss. It is important to remember that severe bleeding can occur in all fracture patterns and one must take into account the entire clinical picture, which should guide the resuscitation and interventions.17,271 
In the hypotensive patient with a pelvic ring fracture and no other source for hemorrhage, acute resuscitation of the patient may include emergent stabilization of the unstable pelvic ring fracture. These techniques include traction, military (or medical) antishock trousers (MAST), sheets, commercially available binders, and external fixation.24,276,279 Angiographic embolization to control arterial hemorrhage should also be part of the overall management of a patient with pelvic hemorrhage, but its use is unique to each institution.54,124,171 Retroperitoneal pelvic packing, which has been performed with some frequency overseas,86,89,104 has gained some popularity here in the United States56,230 at certain centers. It is clear that all of these interventions should be considered and pelvic hemorrhage management algorithm should be based on institutional capabilities.99,214,271 Such algorithms can improve outcomes as shown by a review of the German Trauma Registry over a 10-year period, during which the mortality directly due to pelvic injury and its resultant hemorrhage decreased significantly from 11% to 7% when such a protocol was initiated.127 
Transfusion Requirements.
Although certain pelvic ring fracture patterns are associated with increased blood loss compared to others, it is important to note that the radiographic pattern alone does not necessarily determine the risk of ongoing hemorrhage. The radiograph is a static image and does not accurately portray the displacement that occurred at the time of the impact. Early work by Dalal et al.60 showed that the most severe APC injury, APC type III, has a high rate of circulatory shock (67%) and greater blood loss and transfusion requirements than other types of injury patterns. In a subsequent study by Burgess et al.33 LC patterns also had a much lower blood utilization in the first day than the APC patterns (5.8 units vs. 28.4 units, respectively). However, a more recent study showed an equal number of arterial bleeding sites for APC and LC injuries, although APC injuries still had greater transfusion requirements.199 The increased transfusion requirements of unstable fracture patterns as defined by the Young and Burgess classification continue to hold true. Magnussen et al.180 showed that 62% of the patients with an APC III injury required a mean blood transfusion of 12.6 units versus 60% of LC III patients, who required only a mean blood transfusion of 4.0 units. A recent study from Shock Trauma183 also confirmed the utility of the Young and Burgess classification in predicting transfusion requirements. The APC II and III and the LC II and III patterns required significantly more units of blood than did the stable patterns. However, mortality and nonorthopedic injuries could be predicted only by dividing patterns into stable and unstable groups. Transfusions should be undertaken as needed to manage hemodynamic instability in patients in whom the pelvic fracture is the suspected sole cause of hemorrhage. If the patient remains hypotensive after appropriate and adequate fluid resuscitation, either pelvic arterial bleeding or coagulopathy should be suspected. Unfortunately, patients with higher transfusion requirements tend to have an increased risk of death.133,372 These scenarios require emergent intervention to prevent continued blood loss and shock, and subsequent death.84 
Binders/MAST.
Closing the pelvic diastasis in open-book–type injuries reduces the pelvic volume available for hemorrhage, thereby improving the chance of tamponade and clot formation.84,103,117,197,237 This can be performed with either invasive or noninvasive devices. Clot stabilization and decreased bleeding also occur with stabilization of the fracture, which reduces the motion of the fragments. The earliest forms of external compression devices were the pneumatic antishock garment (PASG) and the military (or medical) antishock trousers (MAST), which were inflatable garments. Complications from the use of these devices included compartment syndrome and extensive skin necrosis, especially in the setting of a concomitant internal degloving injury. In addition, access to the abdomen for examination was precluded and necessitated device removal to address abdominal issues. Subsequent studies have shown that simple frames are equally effective,29,102,192 and the use of these garments/trousers has fallen out of favor. Both pelvic binders and external fixators can achieve the same goal with much less morbidity. 
The purpose of external compression is the following: (a) To close the open-book pelvic injury, which reduces the pelvic volume thereby allowing for a tamponade effect; (b) to stabilize the pelvic ring injury, which allows for clot formation; and (c) allow for autotransfusion by returning the blood from the lower extremities to the vascular system.192 These goals can easily be accomplished with a circumferential folded bed sheet279 or pelvic binder. In a cadaveric study comparing an experimental pelvic sling (with the ability to monitor the tension applied) to both a C-clamp and anterior external fixation, the pelvic sling was comparable to the C-clamp in providing stability but was less effective than an anterior external fixator and thus was felt to be excellent for temporary use to aid in resuscitation in the acute phase.25 A separate biomechanical study looking at commercially available binders (Pelvic binder, SAM Sling, T-Pod) also showed that all can effectively reduce the pelvic injury.155 For optimal reduction of the APC injury, a binder should be placed at the level of the greater trochanters.19,25 Adduction and internal rotation of the extremities, if uninjured, can also assist in reducing the pelvic ring fracture. It has been estimated that approximately 180 N of force is required to close the ring in a cadaveric model,25 but the amount of force required to obtain a reduction has varied based on the device used.155 
It is clear that biomechanically, external pelvic compression devices can reduce pelvic volume. However, in a three-dimensional (3D) modeling utilizing CT scans, the pelvis was determined to be a hemielliptical sphere and its volume did not increase dramatically with an increase in the radius or diameter of the pelvis.332 These authors felt that bleeding could be controlled by compressing and stabilizing the fracture, rather than by reducing pelvic volume per se. In a clinical trial, binders were found to decrease blood loss and transfusion requirements at both 24 hours and 48 hours when compared to external fixation, likely due to their earlier placement.164 A retrospective review of patients admitted to a Level I trauma center over a 10-year period confirmed the reduction in transfusion requirements as well as in length of stay, but the use of angiography and mortality was similar in the two groups.57 This is controversial as in another single-institution retrospective study, the use of a binder on arrival in the emergency department in hypotensive patients had no effect on 24-hour transfusion requirements, mortality, or need for angioembolization.101 A clear clinical advantage is that binders can be applied safely and quickly in the field by EMS personnel or in the trauma bay by caregivers who are not familiar with external fixation24,64 (Fig. 46-8A–D). Because application of a binder in the field is based entirely on clinical examination and intuition, there has been concern about “overreduction” in “undiagnosed” unstable lateral compression injury, but a cadaveric study indicated that a specific tension-controlled sling device could be placed safely in such situations without such concerns.25 Toth et al. showed, in a clinical study, that external pelvic compression devices were also found to be safe without causing additional trauma.349 Overreduction can occur in some cases (Fig. 46-9A, B) and theoretical concerns remain about use of these devices in lateral compression injuries, a pattern for which use is not warranted. In these injuries rami fracture spikes may be driven across the midline with resultant bladder or vessel injury (Fig. 46-10A, B), No clinical data have been published to date confirming these hazards. The use of such devices in the field for all patterns of “undiagnosed” pelvic injury continues in some areas and is recommended by ATLS guidelines.3 However, it is also important to note that prolonged use should be avoided as soft tissue problems can result if the compression is maintained for extended periods, especially if use is combined with prolonged immobilization on a spine board.156 The problems range from pressure ulcerations to full-thickness skin necrosis and resultant sloughing, and these are especially problematic in critically ill intensive care unit (ICU) patients who cannot provide conscious feedback. It has been recommended that such devices be removed as soon as the patient’s hemodynamic status has been stabilized, but that they can be left in place up to 24 hours without substantial problems.143 
Figure 46-8
Patient brought in by EMS with pelvic binder in place.
 
A: Initial AP with binder. B, C: CT scan cut showing axials with binder in place suggestive of an APC injury with closure of posterior lesion. D: AP after binder removed showing widening.
A: Initial AP with binder. B, C: CT scan cut showing axials with binder in place suggestive of an APC injury with closure of posterior lesion. D: AP after binder removed showing widening.
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Figure 46-8
Patient brought in by EMS with pelvic binder in place.
A: Initial AP with binder. B, C: CT scan cut showing axials with binder in place suggestive of an APC injury with closure of posterior lesion. D: AP after binder removed showing widening.
A: Initial AP with binder. B, C: CT scan cut showing axials with binder in place suggestive of an APC injury with closure of posterior lesion. D: AP after binder removed showing widening.
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Figure 46-9
Patient with open pelvic ring injury from MVC injection.
 
A: Injury film showing probable combined mechanism injury owning to injection with bilateral injuries. B: Overreduction with pelvic binder.
A: Injury film showing probable combined mechanism injury owning to injection with bilateral injuries. B: Overreduction with pelvic binder.
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Figure 46-9
Patient with open pelvic ring injury from MVC injection.
A: Injury film showing probable combined mechanism injury owning to injection with bilateral injuries. B: Overreduction with pelvic binder.
A: Injury film showing probable combined mechanism injury owning to injection with bilateral injuries. B: Overreduction with pelvic binder.
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Figure 46-10
 
A: Inlet film showing anterior ring fractures prebinder. B: Binder in place (skinny blue arrow) and superior rami fracture (red arrow) showing potential for injury (thick blue arrow) to bladder (yellow sphere).
A: Inlet film showing anterior ring fractures prebinder. B: Binder in place (skinny blue arrow) and superior rami fracture (red arrow) showing potential for injury (thick blue arrow) to bladder (yellow sphere).
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Figure 46-10
A: Inlet film showing anterior ring fractures prebinder. B: Binder in place (skinny blue arrow) and superior rami fracture (red arrow) showing potential for injury (thick blue arrow) to bladder (yellow sphere).
A: Inlet film showing anterior ring fractures prebinder. B: Binder in place (skinny blue arrow) and superior rami fracture (red arrow) showing potential for injury (thick blue arrow) to bladder (yellow sphere).
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Emergent External Fixation.
Although binders have almost supplanted the use of emergent external fixation, its use still deserves mentioning. Use of external fixation still remains a viable option for the definitive management of certain pelvic ring injuries as an adjunct to posterior internal fixation, especially when anterior stabilization is required and precluded by soft tissue problems or genitourinary injuries. Emergent external fixation was traditionally undertaken with a C-clamp placed either anteriorly or posteriorly,88 placed percutaneously and blindly; or an anterior external fixator with pins in the iliac crests, or more recently in the supra-acetabular region.86 The ideal position for such frames is discussed later under the heading Operative Management.150,197,353 Although trauma surgeons in Europe were the early pioneers in the use of external fixation as part of an aggressive resuscitative measure to aid in the control of bleeding from a pelvic ring fracture,84,151 centers in the US started adapting this technique in an effort to reduce mortality.169,266 These devices were placed in a way that would still allow access to the abdomen in cases of emergent laparotomy. 
If the posterior ring is intact, the anterior external fixator can reduce the pelvic widening to its anatomic position. The fixator is used to internally rotate each hemipelvis, thereby closing an “open-book” injury or emergently re-establishing some pelvic ring geometry (Fig. 46-11A–C). The posterior ring acts as a hinge around which the rotation is centered, but when the posterior ligamentous structures are disrupted, perfect reduction is difficult to obtain and certainly cannot be treated definitively with the anterior frame as shown in Figures 46-11A–C. This is not true for the pelvic C-clamp, which functions by translating the hemipelvis medially76,246 This was felt to be a superior method in cases with posterior disruption because of the better control of the posterior lesion, but it can also be used to treat the anterior ring. The tines of the clamp function as a pointed reduction clamp does in other fractures. Classically, the tips of the clamps were placed onto the external iliac fossa to apply this medially directed force. Because this was done without fluoroscopic imaging, problems arose to include iatrogenic visceral injuries. Placement of the tips more anteriorly on the gluteus ridge has been described as an alternative option, which was effective in APC type II injuries.263 C-Clamps are used in the emergent setting primarily and are not indicated for the definitive treatment of a pelvic ring injury. In cases in which ORIF of the anterior injury is contraindicated, anterior external fixation is an effective option. 
Figure 46-11
Emergently placed anterior ExFix on patient from Figure 46-10(A) AP, (B) inlet, (C) outlet.
 
Pelvis temporarily reduced awaiting definitive fixation.
Pelvis temporarily reduced awaiting definitive fixation.
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Figure 46-11
Emergently placed anterior ExFix on patient from Figure 46-10(A) AP, (B) inlet, (C) outlet.
Pelvis temporarily reduced awaiting definitive fixation.
Pelvis temporarily reduced awaiting definitive fixation.
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If emergent external fixation is required, an orthopaedic surgeon with expertise in pelvic ring fracture management must be readily available. Utilization of sterile technique and fluoroscopic visualization will provide the best and safest environment in which to apply the external fixator or C-clamp. The C-clamp can be placed quickly in a blind fashion in the situation when the patient is too unstable to go to the operation room, but careful attention to anatomy is critical to avoid injury to neurovascular structures. In patients with pelvic ring fractures who fail to respond to initial fluid resuscitation, arterial bleeding is more likely, and delay in angiography for placement of an external fixator should be avoided by placing the external immobilization in the angiography suite.201 Arterial bleeding has also been shown to be more likely in patients older than 60. In older patients angiography should be considered earlier than in younger patients if such resources are immediately available, and typically these patients should have a contrast enhanced CT to aid in the diagnosis.153 In patients who present in shock without abdominal or thoracic bleeding who do not respond to appropriate resuscitation and external stabilization, laparotomy with pelvic packing or angiography is advocated.76,124 
Complications of emergent external fixation are similar to those of any external fixation and include pin-site infection, aseptic pin loosening, serosanguineous discharge, and adjacent skin necrosis.186 In addition, complications can be extremely problematic for obese patients, especially those with a large pannus. Given the ease of use of pelvic binder devices and the potential complications associated with emergent application of external fixators and C-clamps, the utilization of such invasive devices in the emergency department has been decreasing in frequency. 
Angiography.
The use of pelvic angiography as a first course of action in patients with pelvic ring fractures who are hemodynamically unstable is controversial, since arterial bleeding requiring embolization has been reported to be low.147,201,271 Much of the bleeding occurs from the venous plexus and the cancellous fracture surfaces. However, there is good evidence that suggests that arterial embolization should be performed quickly in the presence of ongoing blood loss despite resuscitative efforts, after other sources have been ruled out and binder application has failed to stabilize the patient, as opposed to waiting for emergent external fixation.11,58,79,86,124,201 Some algorithms perform immediate angiography in the hemodynamically unstable patient when the FAST or CT are negative or there is contrast extravasation on CT scan. Angiography is delayed in the unstable patient that underwent laparotomy for a positive FAST but remains hemodynamically unstable.129,201 Other algorithms use angiography as a last resort after laparotomy in all hemodynamically unstable patients regardless of the FAST exam findings.230,336 Although it is controversial as to who absolutely needs arteriography, Starr et al.321 noted that patients who did require it were older and had higher revised trauma scores. Fracture type has not been found to be predictive in determining those that require arteriography.147 The only clear recommendation for arteriography is in patients with contrast extravasation on CT scanning regardless of hemodynamic stability.18,58 The overall success rates have been reported in the >95% range,99 and arteriography continues to be a useful adjunct in the management of hemorrhage in pelvic ring fractures. 
Most arterial injuries involve the internal iliac artery and its branches (Fig. 46-12A–C).199 Therefore, surgical exploration and ligation is not effective and can lead to uncontrollable hemorrhage.76 Embolization maybe selective, the distal branches of the internal iliacs, or nonselective, the internal iliac branch itself, although the former is preferred.8,336 It has been shown that multiple sites of bleeding can be present up to 40% of the time.79 The most common branches involved are reported as the superior gluteal, lateral sacral, internal pudendal (Fig. 46-12A, B), inferior gluteal, and obturator.34,71,99,147 
Figure 46-12
Patient with pelvic ring injury hemodynamically unstable taken to angiography.
 
A: Angiography image showing bilateral internal iliacs. B: Internal pudendal extravasation. C: Coils placed to embolize internal pudendal.
A: Angiography image showing bilateral internal iliacs. B: Internal pudendal extravasation. C: Coils placed to embolize internal pudendal.
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Figure 46-12
Patient with pelvic ring injury hemodynamically unstable taken to angiography.
A: Angiography image showing bilateral internal iliacs. B: Internal pudendal extravasation. C: Coils placed to embolize internal pudendal.
A: Angiography image showing bilateral internal iliacs. B: Internal pudendal extravasation. C: Coils placed to embolize internal pudendal.
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Despite the effectiveness of the procedure itself, complications from arterial embolization should be considered. Liver necrosis, skin necrosis, nerve damage, femoral head necrosis, bladder necrosis, adverse reaction to contrast, and sexual dysfunction have all been reported.147,219,258 Gluteal necrosis has been a major concern, especially in cases of bilateral embolization, but it is believed to be caused by either prolonged immobilization or direct trauma to the gluteal area as opposed to the actual embolization.58 The overall complication rate is anywhere from 0% to 6%.8,171 
Pelvic Packing.
The use of pelvic packing has been limited to several North American centers despite its widespread use in Europe and Asia.71 This is often done in conjunction with the general surgeons during exploratory laparotomy for other potential intra-abdominal injuries. Thus pelvic packing may be preferable in the unstable and critically ill patient who is already going to the operating room.76 There has been increased use of this technique over the last two decades.56,89,350 Advocates of its use feel that that the majority of bleeding, from the venous system and fracture surfaces, is directly addressed with pelvic packing and external fixation with embolization used as a secondary procedure.34,36 For pelvic packing to be effective, it is important to note that the pelvis must be stabilized either with a C-clamp or external fixation such that a stable wall exists against which the packing can occur.336 In a retrospective review, comparing pelvic packing to angiography, the pelvic packing group had a decrease in the amount of blood transfused within the first 24 hours after the procedure, which was not seen in the arteriography group. However, overall transfusion requirements, complications, and mortality rates were similar.230 A review of the literature supports the use of pelvic packing as part of a damage control protocol and should be part of one’s armamentarium.233 The EAST guidelines gives pelvic packing a Level III recommendation for its use as a salvage technique after embolization as well as part of a multidisciplinary pathway in controlling hemorrhage.58 

Imaging and Diagnostic Studies for Pelvic Ring Fractures

Plain Radiography

Plain radiographs are still the mainstay of initial diagnostic imaging, although recent clinical trends have made plain films an afterthought. The most recent ATLS protocol3 (8th edition) still recommends an AP pelvis as part of the initial trauma radiographs: “An anteroposterior (AP) view of the pelvis should be obtained early for all patients with multiple injuries who have no hemodynamic abnormalities and for whom a source of bleeding has not been identified.”3 However, many institutions have increased their use of immediate CT scan as the initial diagnostic examination. Some trauma surgeons have an integrated trauma CT protocol with complete imaging of the trauma patient (head, spine, chest, abdomen, and pelvis).310 The use of an early full-body CT scan was shown to have an association with increased survival.135 There are concerns with this protocol regarding radiation dose and intravenous contrast, which may limit its widespread acceptance and use. 
Dedicated films are often ordered once confirmatory evidence of a pelvic ring fracture exists. “Ghost” images have also been used in increasing frequency, and the argument has been made that this obviates the need for true AP, inlet, and outlet films (Fig. 46-13A–F). Unlike acetabular Judet views, where there is a “dynamic” component because the position of the patient changes, for outlet and inlet views the beam changes, so ghost images may be satisfactory if the image quality remains high. The advantage of such reconstructed images is that they allow for manipulation to correct rotation and angulation as opposed to plain radiographs, which may be malpositioned. However, if plain films are obtained, attempts should be made to obtain the best images possible. The AP radiograph should not be rotated. The pubic symphysis should be midline and collinear with the sacral spinous processes, but with injury it is difficult to use as a guide. If the patient’s torso is not rotated, the lumbar spinous processes being centered within the pedicles can be utilized and more reliable in pelvic ring injuries (Fig. 46-14). However, one must be aware of the patient who has a subtle lumbar scoliosis. Such properly aligned imaging will facilitate diagnosis especially in subtle posterior injuries. Any asymmetry either in the sacroiliac (SI) joint or sacral foramina can be indicative of pathology such as a SI joint dislocation or sacral fracture, and underscores the importance of a centered AP to allow for such side-to-side comparisons. Because the pelvis is a ring structure, when a fracture occurs, a minimum of two injuries will be present. If symphyseal diastasis or displaced rami fractures are seen, one should seek out the additional injury, which is usually in the posterior pelvis. In a recent study, 97% of patients with pubic rami fractures were found to have an injury in the posterior pelvic ring, with a predominance of transforaminal sacral fractures.292 Other subtle injuries can indicate underlying severe pathology. L5 transverse process fractures, called the “sentinel sign” for a VS injury, typically represent an avulsion fracture by the iliolumbar ligaments. 
Figure 46-13
 
Patient with APC III injury and respective plain radiographs and matching ghost images—(A, B) AP, (C, D) inlet, and (E, F) outlet.
Patient with APC III injury and respective plain radiographs and matching ghost images—(A, B) AP, (C, D) inlet, and (E, F) outlet.
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Figure 46-13
Patient with APC III injury and respective plain radiographs and matching ghost images—(A, B) AP, (C, D) inlet, and (E, F) outlet.
Patient with APC III injury and respective plain radiographs and matching ghost images—(A, B) AP, (C, D) inlet, and (E, F) outlet.
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Figure 46-14
 
Patient with APC II injury, showing disruption of symphysis and inability to use it as a guide for rotation; dotted line on lumbar spinous processes showing excellent AP film without any evidence of rotation.
Patient with APC II injury, showing disruption of symphysis and inability to use it as a guide for rotation; dotted line on lumbar spinous processes showing excellent AP film without any evidence of rotation.
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Figure 46-14
Patient with APC II injury, showing disruption of symphysis and inability to use it as a guide for rotation; dotted line on lumbar spinous processes showing excellent AP film without any evidence of rotation.
Patient with APC II injury, showing disruption of symphysis and inability to use it as a guide for rotation; dotted line on lumbar spinous processes showing excellent AP film without any evidence of rotation.
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The AP view is done with the patient supine on the imaging table. The beam is centered directly over the pelvis. All structures of the pelvic ring can be assessed for injury on this view. Although displacement is generally visible on this view, the inlet and outlet views help to identify the exact direction of the displacement as do orthogonal radiographs in other skeletal regions. It is important to appreciate any peculiarity in the appearance of the sacrum on the AP view. Any of the following findings indicate a dysmorphic sacrum (see Fig. 46-80B): (a) the upper sacrum being collinear with the iliac crest; (b) presence of mammillary processes in the alar region; (c) uppermost sacral foramen are larger, misshapen, and irregular; (iv) residual disk space between the dysmorphic upper and second sacral segments; (v) alar slope is more acute on lateral sacral view and thus is not collinear with the iliac cortical density; (vi) tongue-in-groove SI articulation visible on CT scan; or (vii) an anterior cortical indentation is present in the dysmorphic sacral ala.200 If the upper sacrum appears to be in a different orientation than the distal sacrum, a lateral pelvic or sacral radiograph should be obtained. Such injuries can be further delineated by CT scans and reconstructions. 
The inlet (Fig. 46-13C) and outlet (Fig. 46-13E) views are obtained by directing the x-ray beam 45 degrees (up to 60 degrees) caudally and cephalad (Fig. 46-15A, B), respectively, to the radiographic plate and aid in the diagnosis and management of these injuries.225 However, obtaining these views may require adjustments in the angle due to the patient’s pelvic obliquity and sacral inclination. These angles were questions in a retrospective CT scan study. Investigators looked at the “ideal” angle in this population of patients, and they found that 25 degrees for the inlet and 60 degrees for the outlet were the optimal angles for images.262 This was true irrespective of the patient’s sex or the presence of sacral dysmorphism. 
Figure 46-15
Schematic representing the direction of the incident x-ray beam for (A) inlet projection and (B) outlet projection of the pelvic ring.
Rockwood-ch046-image015.png
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The inlet view allows for assessment of an internal or external rotation of each hemipelvis in addition to opening of the SI joint. Impaction fractures of the sacral ala are best seen on this view. Because this is a direct view “into” the pelvis from above, any anterior or posterior displacement in the plane of the sacrum is also well visualized. 
The outlet view allows for evaluation of sacral fractures with respect to the foramina. Adequate outlet views are in the plane of the foramen, and are visualized as close to circular, as well as the SI joints. Most important, the relationship of each side of the symphysis to one another and the ischia to one another allows for detection of flexion or extension deformities in unstable pelvic ring patterns. 
Although, these “oblique” images show displacement in a particular direction, it is important to note that the amount of translation is always a sum of the displacement vectors in two planes. Hence on an outlet view, any “vertical” displacement is still accompanied by anterior or posterior translation seen on the inlet view. Each view must be interpreted within the context of the other. 
Single-leg-stance radiographs, the “Flamingo” views, are dynamic views that can aid in identifying occult instability that otherwise may be overlooked.301 It is important to note that up to 5 mm of physiologic motion and translation occurs when obtaining these stress views in women, particularly if they have had children.96 The clinical setting in which to obtain these views is still unclear and their utilization ill defined, but they are most useful in late cases where instability is suspected.290 
The complex anatomy of the pelvis mandates CT scan evaluation for pelvic ring injuries. The CT scan has become integral in the management of pelvic ring injuries and can aid in the classification of injuries.157 Many injuries may be subtle and not visualized clearly on plain radiography. Because the pelvis is a ring structure, one must always remember that a disruption in one location is accompanied by a second disruption somewhere in the pelvic ring. The CT scan can aid in the recognition of many of these injuries that go undetected on plain radiographs. Axial cuts of the CT scan should be done in 2- to 3-mm increments. Larger axial slices may miss fractures in the axial plane and thus will not be seen on the reconstructed images. In addition, the quality of reconstructed images is improved with finer cuts. This is especially true for the three-dimensional reconstructions (Fig. 46-16A–G). The 3D and other reconstructed images can assist in determination of the surgical approach to be used. The sagittal sacral reconstructions are especially useful to evaluate for the presence of kyphosis, which may be indicative of a sacral fracture-dislocation, U-shaped sacral fracture, or a spinopelvic disassociation291 (Fig. 46-17A–C). 
Figure 46-16
CT scan images for patient with LC II injury.
 
A: Axial cut. B: Coronal. C: Three-dimensional AP. D: Three-dimensional inlet. E: Three-dimensional outlet. F: The 3D image can be manipulated and rotated to visualize injury (180-degree rotation for posterior view). G: A 3D rotation for lateral image depicting crescent fracture.
A: Axial cut. B: Coronal. C: Three-dimensional AP. D: Three-dimensional inlet. E: Three-dimensional outlet. F: The 3D image can be manipulated and rotated to visualize injury (180-degree rotation for posterior view). G: A 3D rotation for lateral image depicting crescent fracture.
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A: Axial cut. B: Coronal. C: Three-dimensional AP. D: Three-dimensional inlet. E: Three-dimensional outlet. F: The 3D image can be manipulated and rotated to visualize injury (180-degree rotation for posterior view). G: A 3D rotation for lateral image depicting crescent fracture.
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Figure 46-16
CT scan images for patient with LC II injury.
A: Axial cut. B: Coronal. C: Three-dimensional AP. D: Three-dimensional inlet. E: Three-dimensional outlet. F: The 3D image can be manipulated and rotated to visualize injury (180-degree rotation for posterior view). G: A 3D rotation for lateral image depicting crescent fracture.
A: Axial cut. B: Coronal. C: Three-dimensional AP. D: Three-dimensional inlet. E: Three-dimensional outlet. F: The 3D image can be manipulated and rotated to visualize injury (180-degree rotation for posterior view). G: A 3D rotation for lateral image depicting crescent fracture.
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A: Axial cut. B: Coronal. C: Three-dimensional AP. D: Three-dimensional inlet. E: Three-dimensional outlet. F: The 3D image can be manipulated and rotated to visualize injury (180-degree rotation for posterior view). G: A 3D rotation for lateral image depicting crescent fracture.
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Figure 46-17
Patient with spinopelvic disassociation.
 
A: Axial cut clearly shows bilateral sacral fractures. B: Sagittal reconstruction shows the kyphotic deformity seen with spinopelvic disassociations. C: A 3D CT scan with H-type fracture outlined in red.
A: Axial cut clearly shows bilateral sacral fractures. B: Sagittal reconstruction shows the kyphotic deformity seen with spinopelvic disassociations. C: A 3D CT scan with H-type fracture outlined in red.
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Figure 46-17
Patient with spinopelvic disassociation.
A: Axial cut clearly shows bilateral sacral fractures. B: Sagittal reconstruction shows the kyphotic deformity seen with spinopelvic disassociations. C: A 3D CT scan with H-type fracture outlined in red.
A: Axial cut clearly shows bilateral sacral fractures. B: Sagittal reconstruction shows the kyphotic deformity seen with spinopelvic disassociations. C: A 3D CT scan with H-type fracture outlined in red.
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Fluoroscopic Stress Examinations

Fracture classifications are based on the radiographic appearance of the pelvis. It is important to note because the AP, inlet, and outlet radiographs as well as the CT scan at the time of presentation are static images; the displacement that occurred at the time of impact is not necessarily represented. Recently, fluoroscopic stress views to assist in determining instability and the subsequent need for operative stabilization have been recommended. In a series of 68 patients undergoing fluoroscopy after an initial determination of stability, 34 were believed to have stable patterns (APC type I or LC type I), but 41% (14) were actually found to have sufficient instability on stress examination to warrant operative fixation.284 Examination under anesthesia may aid the clinician in determining the degree of instability of pelvic ring injuries and guide treatment (Fig. 46-18A–C). 
Figure 46-18
Patient with LCI showing stable stress exam.
 
A: Fluoro inlet without stress. B: Same view with abduction stress. C: Same view with inward stress.
A: Fluoro inlet without stress. B: Same view with abduction stress. C: Same view with inward stress.
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A: Fluoro inlet without stress. B: Same view with abduction stress. C: Same view with inward stress.
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Figure 46-18
Patient with LCI showing stable stress exam.
A: Fluoro inlet without stress. B: Same view with abduction stress. C: Same view with inward stress.
A: Fluoro inlet without stress. B: Same view with abduction stress. C: Same view with inward stress.
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A: Fluoro inlet without stress. B: Same view with abduction stress. C: Same view with inward stress.
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Magnetic Resonance Imaging

Although magnetic resonance imaging (MRI) has been useful in the management of certain ligamentous injuries, such as that in knee dislocations, its use in pelvic injuries is limited. CT scan imaging provides both fracture and ligamentous disruption information. An understanding of pelvic anatomy, pelvic ring fracture classification schemes, and pelvic biomechanics aids the surgeon in determining the structures injured. There has been no clear benefit to the added use of MRI in the acute management of pelvic ring injuries. However in cases of lumbopelvic dissociation or sacral fractures with neurologic compromise, MRI is of benefit in determining the areas of neural canal compromise and nerve root compression.375 MR venography is also useful for the evaluation of deep vein thrombosis (DVT) in the pelvic veins.212,317 

Classifications of Pelvic Ring Fractures

Like in many areas of orthopaedic trauma, injury classification is helpful as a communication tool and aids in tracking data for research and reporting. In pelvic ring fractures, classification predicts resuscitative requirements as well as outcome.60 
Malgaine182 in 1859 was the first to characterize a pelvic ring fracture, when he reported on a patient with a “double vertical fracture”—this was described as fractures through both the superior and inferior rami anteriorly, with a concomitant fracture or dislocation through the posterior ring. Through the subsequent years there were isolated case reports of patients with pelvic ring fractures.132 The first attempts at classification of these injuries was in 1965 by Peltier238 and then again in 1972 by Huittinen.137 Not only did they try to classify the injury based on mechanism, but attempted to correlate it with both complications and outcomes. Pennal241 and Tile343 gave us the first comprehensive classification scheme based on the structural elements of the pelvis that were injured. 
The Tile classification (Table 46-3) is divided into three types: A, B, and C. Type A injuries (A1, A2) are stable and can be managed nonoperatively. Type B injuries (B1-3) include rotationally unstable injuries that are vertically stable. The type C injury (C1-3) is both rotationally and vertically unstable. This classification scheme aids in the understanding of the stability of each pelvic ring fracture and the need for surgical intervention. Investigators have reported outcomes based on the Tile classification. Type C injuries tend to have the worse outcomes, predominately because of associated neurologic injuries.269 However, the most widely used classification scheme today is that of Young and Burgess378 (Table 46-4). This classification is based on the mechanism of injury. There are four types described: Lateral compression (LC I-III), anterior-posterior compression (APC I-III), vertical shear (VS), and combined mechanism (CM). 
 
Table 46-3
Tile Classification
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Table 46-3
Tile Classification
Type A: Pelvic Ring Stable
  •  
    A1: fractures not involving the ring (i.e., avulsions, iliac wing, or crest fractures)
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    A2: stable minimally displaced fractures of the pelvic ring
Type B: Pelvic Ring Rotationally Unstable, Vertically Stable
  •  
    B1: open book
  •  
    B2: lateral compression, ipsilateral
  •  
    B3: lateral compression, contralateral, or bucket-handle-type injury
Type C: Pelvic Ring Rotationally and Vertically Unstable:
  •  
    C1: unilateral
  •  
    C2: bilateral
  •  
    C3: associated with acetabular fracture
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Table 46-4
Young and Burgess Classification
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Table 46-4
Young and Burgess Classification
LC: anterior injury = rami fractures
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    LC I: sacral fracture on side of impact
  •  
    LC II: crescent fracture on side of impact
  •  
    LC III: type I or II injury on side of impact with contralateral open book injury
Anterior-posterior compression (APC): anterior injury = symphysis diastasis/rami fractures
  •  
    APC I: minor opening of symphysis and SI joint anteriorly
  •  
    APC II: opening of anterior SI, intact posterior SI ligaments
  •  
    APC III: complete disruption of SI joint
Vertical shear (VS) type:
Vertical displacement of hemipelvis with symphysis diastasis or rami fractures anteriorly, iliac wing, sacral facture, or sacroiliac dislocation posteriorly
Combined mechanism (CM) type: any combination of above injuries
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Lateral compression injuries are the most common pattern encountered.367 These result from side impact injuries such as T-bone motor vehicle collisions. The hemipelvis on the side of the impact sustains an inward or internal rotation force, often resulting in sacral impaction and/or an iliac wing fracture posteriorly. The anterior injuries usually are rami fractures or occasionally the “locked symphysis.” The pathognomonic finding of this pattern is rami fractures that are in the transverse plane on the inlet view. These injuries may be rotationally unstable but are vertically stable (Tile type B). Some will have some flexion deformity of the hemipelvis. The LC injuries are further subclassified by the posterior lesion. The LC I has a sacral impaction fracture (Fig. 46-19A–E); the typical LC II has an iliac wing fracture or the “crescent” fracture, which is a fracture dislocation of the iliac wing through the SI joint (Fig. 46-20A–D); and the LC III or the “wind-swept” pelvis, which is a composite injury of an LC I or II on the side of impact, with an opening of the contralateral hemipelvis, usually at the SI joint (Fig. 46-21A–G). However, it is becoming more clear that the LC classification comprises a heterogeneous group of fracture patterns due to the variability in the posterior lesion, namely the sacral fracture morphology in lower grade patterns.367 In addition, the LC II pattern has been subdivided into three subcategories, depending on the level through which the SI joint fracture occurs. It is divided into thirds from anterior to posterior.61 This subclassification may prove useful for surgical decision-making. It seems apparent that the three-level classification scheme of lateral compression injuries by Young and Burgess may be too broad for this group of pelvic ring injuries. 
Figure 46-19
Patient with LCI injury from Figure 46-18.
 
A: AP showing posterior lesion (circled in red and black arrow) and anterior lesions (rami fractures; black arrows). B: CT scan axial cut showing impaction fracture of sacrum (red arrow). C–E: Three-dimensional reconstructions showing injury: AP, inlet, and outlet.
A: AP showing posterior lesion (circled in red and black arrow) and anterior lesions (rami fractures; black arrows). B: CT scan axial cut showing impaction fracture of sacrum (red arrow). C–E: Three-dimensional reconstructions showing injury: AP, inlet, and outlet.
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Figure 46-19
Patient with LCI injury from Figure 46-18.
A: AP showing posterior lesion (circled in red and black arrow) and anterior lesions (rami fractures; black arrows). B: CT scan axial cut showing impaction fracture of sacrum (red arrow). C–E: Three-dimensional reconstructions showing injury: AP, inlet, and outlet.
A: AP showing posterior lesion (circled in red and black arrow) and anterior lesions (rami fractures; black arrows). B: CT scan axial cut showing impaction fracture of sacrum (red arrow). C–E: Three-dimensional reconstructions showing injury: AP, inlet, and outlet.
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A: AP. B: Inlet. C: Outlet. D: CT axial cut.
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Figure 46-20
Patient with LC II showing fracture dislocation (crescent fracture) through left SI joint.
A: AP. B: Inlet. C: Outlet. D: CT axial cut.
A: AP. B: Inlet. C: Outlet. D: CT axial cut.
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Figure 46-21
Patient with LC III fracture with right-sided LC injury and left-sided APC injury.
 
A: AP. B: Inlet. C: Outlet. D: Multiple CT scan images showing right-sided LC injury with sacral fracture and left-sided APC injury with SI joint widening. E–G: Three-dimensional CT scan reconstructions of AP, inlet, and outlet views.
A: AP. B: Inlet. C: Outlet. D: Multiple CT scan images showing right-sided LC injury with sacral fracture and left-sided APC injury with SI joint widening. E–G: Three-dimensional CT scan reconstructions of AP, inlet, and outlet views.
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A: AP. B: Inlet. C: Outlet. D: Multiple CT scan images showing right-sided LC injury with sacral fracture and left-sided APC injury with SI joint widening. E–G: Three-dimensional CT scan reconstructions of AP, inlet, and outlet views.
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Figure 46-21
Patient with LC III fracture with right-sided LC injury and left-sided APC injury.
A: AP. B: Inlet. C: Outlet. D: Multiple CT scan images showing right-sided LC injury with sacral fracture and left-sided APC injury with SI joint widening. E–G: Three-dimensional CT scan reconstructions of AP, inlet, and outlet views.
A: AP. B: Inlet. C: Outlet. D: Multiple CT scan images showing right-sided LC injury with sacral fracture and left-sided APC injury with SI joint widening. E–G: Three-dimensional CT scan reconstructions of AP, inlet, and outlet views.
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A: AP. B: Inlet. C: Outlet. D: Multiple CT scan images showing right-sided LC injury with sacral fracture and left-sided APC injury with SI joint widening. E–G: Three-dimensional CT scan reconstructions of AP, inlet, and outlet views.
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The “open-book” pelvis or APC injury was described as anterior-posterior in nature, but can be from posterior to anterior, and in most cases is caused by severe external rotation of one hemipelvis such as those from motorcycle accidents where one leg is sharply rotated. As the injury force progresses from anterior to posterior, an external rotation of one or both hemipelvises occurs and is hinged posteriorly through the SI joints or sacrum. Ligamentous structures fail in a dominolike pattern with the symphysis failing first. Isolated injury to the symphysis results in an APC I injury (Fig. 46-22A–F). As the force continues posteriorly, there is an increasing external rotation and abduction force that is applied to each hemipelvis. Sequential failure of the sacrotuberous (ST), sacrospinous (SSp), and anterior sacroiliac (ASI) ligaments occurs under tension. Injury to these structures results in an APC II pattern (Fig. 46-23A–F). A symphyseal diastasis >2.5 cm, classically indicated disruption of all these structures, thus differentiating the APC I from the APC II injury. This 2.5-cm cutoff has recently been questioned in a cadaveric model, where the anterior sacroiliac ligaments did not disrupt in some case until 4.5 cm.69 However, the overall average symphysis diastasis measured when the anterior sacroiliac ligaments failed was approximately 2.2 cm, which does support the original value described. In addition, the sacrospinous and sacrotuberous ligaments only disrupted 15% of the time, with the anterior sacroiliac ligaments always disrupting, which is contrary to the original sequence of events. The exact clinical significance of their findings has yet to be elucidated. Continued external rotation force results in disruption of the intraarticular and posterior SI ligaments, producing a completely unstable SI joint and an APC III pattern (Fig. 46-24A–E). Biomechanical cadaveric studies show that at this stage all the supporting ligamentous structures of the pelvic ring, including the pelvic floor and perineal musculature, have been completely disrupted.128,364 
Figure 46-22
Patient with an APC I injury.
 
A: AP view showing widened symphysis. B, C: CT scan axial and coronal cuts showing measurement of <2.5 cm at symphysis. D–F: Three-dimensional reconstructions of AP, inlet, and outlet views—note the left ramus fracture with external rotation displacement.
A: AP view showing widened symphysis. B, C: CT scan axial and coronal cuts showing measurement of <2.5 cm at symphysis. D–F: Three-dimensional reconstructions of AP, inlet, and outlet views—note the left ramus fracture with external rotation displacement.
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Figure 46-22
Patient with an APC I injury.
A: AP view showing widened symphysis. B, C: CT scan axial and coronal cuts showing measurement of <2.5 cm at symphysis. D–F: Three-dimensional reconstructions of AP, inlet, and outlet views—note the left ramus fracture with external rotation displacement.
A: AP view showing widened symphysis. B, C: CT scan axial and coronal cuts showing measurement of <2.5 cm at symphysis. D–F: Three-dimensional reconstructions of AP, inlet, and outlet views—note the left ramus fracture with external rotation displacement.
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Figure 46-23
Patient with APC II injury.
 
A–C: AP, inlet, and outlet views. D: CT scan posterior axial cut showing widening of right SI joint. E: CT scan anterior axial cut showing >5.7 cm widening. F: A 3D reconstruction of AP view showing APC II injury.
A–C: AP, inlet, and outlet views. D: CT scan posterior axial cut showing widening of right SI joint. E: CT scan anterior axial cut showing >5.7 cm widening. F: A 3D reconstruction of AP view showing APC II injury.
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Figure 46-23
Patient with APC II injury.
A–C: AP, inlet, and outlet views. D: CT scan posterior axial cut showing widening of right SI joint. E: CT scan anterior axial cut showing >5.7 cm widening. F: A 3D reconstruction of AP view showing APC II injury.
A–C: AP, inlet, and outlet views. D: CT scan posterior axial cut showing widening of right SI joint. E: CT scan anterior axial cut showing >5.7 cm widening. F: A 3D reconstruction of AP view showing APC II injury.
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Figure 46-24
Patient with APC III injury.
 
A–C: AP, inlet, and outlet views. D: CT scan showing complete left SI joint dislocation. E: A 3D CT reconstruction of the AP view.
A–C: AP, inlet, and outlet views. D: CT scan showing complete left SI joint dislocation. E: A 3D CT reconstruction of the AP view.
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Figure 46-24
Patient with APC III injury.
A–C: AP, inlet, and outlet views. D: CT scan showing complete left SI joint dislocation. E: A 3D CT reconstruction of the AP view.
A–C: AP, inlet, and outlet views. D: CT scan showing complete left SI joint dislocation. E: A 3D CT reconstruction of the AP view.
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Falls from a significant height can result in VS injuries. The primary force vector is directed cephalad. The injured hemipelvis is displaced vertically, and on x-ray the iliac crest is seen to be cephalad when compared to the contralateral side. A vertically unstable hemipelvis can be indicated by a transverse process fracture of L5, which has been avulsed by the iliolumbar ligament (Fig. 46-25A–G). It is also important to evaluate these patients for associated calcaneus and spinal fractures. 
Figure 46-25
Patient with vertical shear injury.
 
A–C: AP, inlet, and outlet views showing vertical displacement of right hemipelvis through a complete sacral fracture and transverse process fracture avulsion (indicated by arrow). D, E: CT scan cuts axial and coronal. F, G: Three-dimensional CT scan reconstructions of inlet and outlet views.
A–C: AP, inlet, and outlet views showing vertical displacement of right hemipelvis through a complete sacral fracture and transverse process fracture avulsion (indicated by arrow). D, E: CT scan cuts axial and coronal. F, G: Three-dimensional CT scan reconstructions of inlet and outlet views.
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A–C: AP, inlet, and outlet views showing vertical displacement of right hemipelvis through a complete sacral fracture and transverse process fracture avulsion (indicated by arrow). D, E: CT scan cuts axial and coronal. F, G: Three-dimensional CT scan reconstructions of inlet and outlet views.
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Figure 46-25
Patient with vertical shear injury.
A–C: AP, inlet, and outlet views showing vertical displacement of right hemipelvis through a complete sacral fracture and transverse process fracture avulsion (indicated by arrow). D, E: CT scan cuts axial and coronal. F, G: Three-dimensional CT scan reconstructions of inlet and outlet views.
A–C: AP, inlet, and outlet views showing vertical displacement of right hemipelvis through a complete sacral fracture and transverse process fracture avulsion (indicated by arrow). D, E: CT scan cuts axial and coronal. F, G: Three-dimensional CT scan reconstructions of inlet and outlet views.
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A–C: AP, inlet, and outlet views showing vertical displacement of right hemipelvis through a complete sacral fracture and transverse process fracture avulsion (indicated by arrow). D, E: CT scan cuts axial and coronal. F, G: Three-dimensional CT scan reconstructions of inlet and outlet views.
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In situations where multiple force vectors result in an injury, a CM pattern is usually seen. These pelvic ring fractures exhibit features from two or more of the other types of patterns (Fig. 46-26A–G). These patients usually are ejected from a vehicle involved in motorcycle or industrial accidents. 
Figure 46-26
Patient with CM pelvic ring injury.
 
A–C: AP, inlet, and outlet views showing multiple patterns of APC, VS, and LC injuries. D: CT scan axial cut showing posterior injuries. E–G: Three-dimensional CT scan reconstructions of AP, inlet, and outlet views showing the multiple patterns of injury.
A–C: AP, inlet, and outlet views showing multiple patterns of APC, VS, and LC injuries. D: CT scan axial cut showing posterior injuries. E–G: Three-dimensional CT scan reconstructions of AP, inlet, and outlet views showing the multiple patterns of injury.
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A–C: AP, inlet, and outlet views showing multiple patterns of APC, VS, and LC injuries. D: CT scan axial cut showing posterior injuries. E–G: Three-dimensional CT scan reconstructions of AP, inlet, and outlet views showing the multiple patterns of injury.
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Figure 46-26
Patient with CM pelvic ring injury.
A–C: AP, inlet, and outlet views showing multiple patterns of APC, VS, and LC injuries. D: CT scan axial cut showing posterior injuries. E–G: Three-dimensional CT scan reconstructions of AP, inlet, and outlet views showing the multiple patterns of injury.
A–C: AP, inlet, and outlet views showing multiple patterns of APC, VS, and LC injuries. D: CT scan axial cut showing posterior injuries. E–G: Three-dimensional CT scan reconstructions of AP, inlet, and outlet views showing the multiple patterns of injury.
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A–C: AP, inlet, and outlet views showing multiple patterns of APC, VS, and LC injuries. D: CT scan axial cut showing posterior injuries. E–G: Three-dimensional CT scan reconstructions of AP, inlet, and outlet views showing the multiple patterns of injury.
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The Orthopaedic Trauma Association229 along with the Association for the Study of Internal Fixation has described a more comprehensive classification scheme.363 It is utilized primarily for data collection and reporting. The classification systems described do not really aid in planning the surgical approach, operative fixation, or functional outcome for a particular patient. Instead for treatment purposes, it is often more useful to separate the pelvic ring fracture into anterior and posterior injuries. 
Injuries can be fractures or ligamentous disruptions and can occur in varying combinations. Anteriorly the injury can be in the form of rami fractures, pubic body fractures, or symphyseal disruptions. Occasionally the anterior ring fracture can be in the form of an acetabular fracture. The posterior lesion can be represented by a sacral fracture, SI joint dislocation, crescent fracture (SI fracture-dislocation), or an iliac wing fracture. The overall fracture pattern taking into account the posterior and anterior lesions, associated gastrointestinal and genitourinary injuries, the condition of the patient, and the soft tissues will guide the final treatment and rehabilitative plan. 
Recently, Rommens and Hoffman270 published a comprehensive classification for fragility fractures of the pelvic ring (FFP). They describe four types each with subclassifications. The FFP type I involves the anterior ring only. The FFP type II has a nondisplaced posterior injury with varying degrees of anterior involvement. An FFP type III fracture has a displaced unilateral posterior injury, whereas the FFP type IV is bilateral. Recommendations for surgical management are based on the classification. Type I fractures generally can be treated nonoperatively, whereas surgical intervention has been recommended for types II through IV. 

Classification of Sacral Fractures

Sacral fractures are most commonly classified by the system described by Denis.66 It categorizes the fractures based on the fracture line orientation and location with respect to the sacral foramina. Vertical or oblique fractures that occur just lateral to the sacral foramina are considered Zone I fractures (Fig. 46-27). This is the most common pattern, comprising almost 50% of injuries. Because the fracture is lateral to the foramen, the rate of neurologic injury is low. When the fracture line enters the sacral foramina, it is classified as a Zone II injury, and these account for about one third of all sacral fractures (Fig. 46-28). These fractures are accompanied by a neurologic deficit in 30% of cases. The Zone III injury is a much more heterogeneous group of fracture patterns compared to Zone I or 2 injuries. The fracture lines are all medial to the sacral foramina and enter the spinal canal, but can run in a vertical, oblique, or horizontal direction (Fig. 46-29A, B). Rates of injury to the nerve roots or the cauda equina can be as high as 60% due to extension into the spinal canal. Zone III fractures are the least common of injuries with an incidence of 16%. Pelvic stability is compromised with Zone I or II injuries. Moed207 described the vertical midline “split” that is associated with unstable APC injuries of the pelvic ring. Horizontal fractures can be easily missed without fine-cut CT scans and sagittal reconstructions. Most of the time these fractures do not affect pelvic stability, but they can affect spinal stability depending on the location of the fracture relative to the SI joints. Fractures below the level of the SI joints are stable injuries, but can cause injury the spinal nerve roots and the cauda equina. Fracture fragments may occlude the canal, resulting in injury to these structures usually at the S3 level and below. When a horizontal fracture occurs at the level of the SI joints, there usually are associated bilateral vertical transforaminal fracture lines, which can result in a U- or H-shaped fracture pattern.166,184,309,311 These injuries occur because of acute hyperflexion of the pelvis and lumbosacral junction, leading to lumbopelvic dissociation as described by Denis,66 Roy-Camille,282 and Strange-Vognsen.333 This “disassociation” results in a loss of continuity between the pelvis and spine that can lead to a kyphotic deformity, impaction, and potential compromise of the sacral spinal canal. This is best seen on sagittal reconstruction images of a fine-cut CT scan of the pelvis as shown previously in Figure 46-17B. This is in contrast to Zone I or II injuries. These highly unstable fractures are a result of either vertical shear forces or rotational forces on the pelvis. In these injuries, spinal stability can be affected if the fracture line extends proximally and disrupts the L5-S1 articulation,140 or transforaminal fractures with comminution, fracture separation and/or vertical instability, and may also require triangular osteosynthesis and spinopelvic fixation.283 
Figure 46-27
CT scan showing Zone I sacral fracture (lateral to the foramen).
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Figure 46-28
CT scan showing Zone II sacral fracture—through the foramen—with fragment (arrow) in the S1 foramen resulting in neuro deficit.
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Figure 46-29
CT scan cuts showing Zone III sacral fracture (A) through the S1 body and (B) lateral to foramen with extension into spinal canal.
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The Roy–Camille282 classification initially had three subtypes but was modified by Strange-Vognsen and Lebech333 to include a fourth subtype. The type 1 patterns have kyphosis (anteriorly flexed) without translation. The type 2 patterns have kyphosis with posterior translation of the cephalad fragment. Type 3 fractures are completely translated injuries, most often with the cephalad fragment anterior to the caudad segment. The type 4 fracture has complete comminution without displacement of the cephalad fragment. In addition, these high-energy fractures have been classified into morphologic variations based on the fracture configurations: “U”, “H”, “T”, and “Y” patterns.375 

Pelvic Ring Fracture Outcomes

Outcomes of pelvic ring fractures have been difficult to evaluate because of the heterogeneity in existing studies and classification schemes. As is the case with many trauma outcome scores, many patients are multiply injured and thus it is a challenge for the functional evaluations to relate the outcome to a particular injury. In the case of isolated pelvic ring fractures, functional scores may provide some information as to the efficacy of surgical and nonsurgical treatment of these potentially horrific injuries. Studies reporting outcomes are flawed in that the patient populations studied are often heterogeneous and evaluate all pelvic injury types. In addition many patients have associated injuries, which have been shown to greatly affect outcome, even more so than the pelvic injury itself. Few studies, if any, standardize treatment protocols such that outcome can be tied to procedure. It is obvious that certain pelvic ring fractures inherently have worse outcomes. The outcome is also related to the reduction for certain types of pelvic ring fractures. 
One of the first reports published that makes a clear distinction between bony and ligamentous injuries with respect to functional outcome was in 1948 by Holdsworth.132 He evaluated 50 patients, and compared those with pure SI dislocations to those with a fracture of the ilium or sacrum. Patient with the pure SI joint dislocation fared worse with respect to return to work than those with fracture. He also noted that functional outcome appeared to be related to the quality of the reduction. Patients with an anatomic or near anatomic reduction appeared to do better functionally. A subsequent study by Raf255 in 1966 showed the same relationship between reduction and functional outcome. He also reported on the high incidence of neurologic injury, chronic pain, and limp, as well as bowel and bladder dysfunction in patients with unstable or displaced high-energy pelvic ring fracture-dislocations. Dujardin70 in 1998 also showed that an anatomic reduction improved functional outcomes. 
There are only four outcome scores designed specifically for use in pelvic ring injuries. The earliest to be described was the Majeed pelvic score in 1989,181 a patient-reported outcome evaluating five areas: Pain (30 points), work (20 points), sitting (10 points), sexual intercourse (4 points), and standing (36 points). Van den Bosch et al.360 looked at the score and validated it against the 36-Item Short Form Health Survey (SF-36). They evaluated a group of 37 patients who had undergone surgical stabilization of their pelvic ring injury. They found general limitations in functioning after long-term follow-up. Anterior fixation yielded good results in partially unstable fractures. In completely unstable fractures, patients treated with internal fixation for both the posterior and anterior injuries had a better outcome than those treated with posterior internal fixation and anterior external fixation. 
Martin et al.185,340 developed the Iowa Pelvic Score (IPS), which is a functional assessment tool focusing on the patient’s own perception of their condition. It evaluates the following six categories: Activities of daily living (20 points), work history (20 points), pain (25 points), limp (20 points), visual pain line (10 points), and cosmesis (5 points). The higher the score, the better the outcome, with 85 to 100 points designated as an excellent outcome. The IPS has been validated against the SF-36 in a study looking at VS injuries where residual displacement in the vertical direction did not correlate with functional outcome.220 
The Orlando pelvic outcome score was described and validated against the SF-36 by Cole et al.,48 but in contrast to the patient-reported SF-36 and IPS, it is a clinician-based outcome. It utilizes six subscales: Functional pain (5 points), subjective pain (4 points), narcotic use (1 point), activity status (10 points), physical exam (10 points), and radiographic (10 points) for a total of 40 points. The investigators reported a heterogeneous group of Tile C pelvic ring fractures and the treatment varied. They did note that associated injuries statistically affected the pelvic outcome score when compared to a group without associated injuries, further highlighting the difficulty in functional outcome evaluation of multiply injured patients. 
The Hannover pelvic score was initially described by Pohlemann et al.,248 and evaluated clinical symptoms and social reintegration. The scale is 1 to 4 for clinical symptoms and 1 to 3 for social factors, with the total score being 7. This has never been validated against the SF-36. Its use has been limited. 
Only the Majeed, Orlando Pelvis Score, and Iowa Pelvis Score have been validated against the SF-36. These measures have been found to be of some use clinically. However, they do have some methodologic constraints, in that they have not been tested for their reliability or responsiveness. In a recent review of the literature that reported outcome scores in the management of pelvic ring fractures, it was clear that the current literature was unable to provide meaningful data about the functional outcome of these injuries after operative repair.171 Most of these studies report outcomes of large series of patients with pelvic ring fracture with various fracture patterns. There are retrospective data to suggest that relative to partially unstable injuries, completely unstable fracture patterns tend to be associated with higher morbidity, varying degrees of long-term impairment and disability, and increased mortality.120,131,144,269,360 In addition, patients with completely unstable injuries fared better with both anterior and posterior internal fixation as opposed to anterior external fixation and posterior internal fixation.269,360 Better outcome measures need to be developed to improve validity, responsiveness, and reproducibility, allowing for the effects of nonpelvic ring associated injuries to be evaluated as well. Further research in the functional outcome after operative repair of pelvic ring fractures is clearly needed. 

Surgical Anatomy and Approaches Relating to Pelvic Ring Fractures

Surgical Anatomy

The pelvis comprises three bones: The sacrum and each hemipelvis, also known as the innominate bones. The innominate bone is a fusion of three embryonic components—the ilium, the ischium, and the pubis (Fig. 46-30). The fusion occurs at the triradiate cartilage where the acetabulum develops. The articulation of the femoral head with the acetabulum allows the transmission of forces from the lower extremities up to the spine by way of the ilium. Thus the bone in the ilium has two columns, which are extremely thick and strong. The first column runs from the ischial tuberosity to the SI joint and allows for force transfer during sitting. The second column runs from the dome of the acetabulum to the SI joint and allows for force transfer during standing. The sciatic buttress, an extremely dense region of bone, is spanned by both columns. Anteriorly the two hemipelvises are joined at the symphysis pubis. The sacrum, which forms from the fusion of five embryonic sacral vertebral bodies, is joined by each hemipelvis posteriorly through the sacroiliac joints (Fig. 46-31). Superiorly it articulates with the L5 vertebral body through the L5-S1 disc space and corresponding facet joints. This bony configuration with its ligamentous support creates a structure that connects the spine to the lower extremities and is often referred to as the spinopelvic junction. The posterior aspect of the pelvic ring serves as part of the spine (sacrum) as well as being the cornerstone for stability of the pelvic ring, namely the sacroiliac joints and their related ligaments. 
Figure 46-30
Bony model of pelvis with indicated landmarks.
 
ASIS, anterior superior iliac spine; AIIS, anterior inferior iliac spine; SI joints, sacroiliac joints.
ASIS, anterior superior iliac spine; AIIS, anterior inferior iliac spine; SI joints, sacroiliac joints.
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Figure 46-30
Bony model of pelvis with indicated landmarks.
ASIS, anterior superior iliac spine; AIIS, anterior inferior iliac spine; SI joints, sacroiliac joints.
ASIS, anterior superior iliac spine; AIIS, anterior inferior iliac spine; SI joints, sacroiliac joints.
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Figure 46-31
Magnified view of bony model of the sacrum viewed in the outlet position.
 
The fusion of five sacral bodies as demonstrated by the black bars. Foramen are seen on the end as visualized in the outlet view.
The fusion of five sacral bodies as demonstrated by the black bars. Foramen are seen on the end as visualized in the outlet view.
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Figure 46-31
Magnified view of bony model of the sacrum viewed in the outlet position.
The fusion of five sacral bodies as demonstrated by the black bars. Foramen are seen on the end as visualized in the outlet view.
The fusion of five sacral bodies as demonstrated by the black bars. Foramen are seen on the end as visualized in the outlet view.
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Because it is formed through fusion of the five sacral bodies, the sacrum is prone to segmentation anomalies, which need to be evaluated as they can affect treatment options and strategies when treating pelvic ring injuries. These segmentation anomalies can be in the form of sacralization of L5 or lumbarization of S1; they can be complete (Fig. 46-32A, B; bilateral) or incomplete (Fig. 46-32C; unilateral). The sacrum forms in such a way that the posterior aspect is convex and anterior concave, and there are varying degrees of kyphosis inherent in the curvature. Such anatomic and geometric subtleties need to be noted when sacral fixation is considered. 
Figure 46-32
Images of a patient with bilateral sacralization of L5 best visualized on (A) outlet view.
 
B: A 3D reconstruction outlet view with red arrows pointing to sacralization. C: Patient with unilateral (right side) sacralization of L5 as indicated by white arrow.
B: A 3D reconstruction outlet view with red arrows pointing to sacralization. C: Patient with unilateral (right side) sacralization of L5 as indicated by white arrow.
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Figure 46-32
Images of a patient with bilateral sacralization of L5 best visualized on (A) outlet view.
B: A 3D reconstruction outlet view with red arrows pointing to sacralization. C: Patient with unilateral (right side) sacralization of L5 as indicated by white arrow.
B: A 3D reconstruction outlet view with red arrows pointing to sacralization. C: Patient with unilateral (right side) sacralization of L5 as indicated by white arrow.
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These three bony structures are held together with strong ligaments. The articulations between each of the bony structures—the bilateral SI joints posteriorly and the symphysis pubis anteriorly—are all inherently unstable. The normal anatomic relationships are maintained secondarily to these strong supporting ligamentous structures. The SI joints are held together with anterior, intra-articular, and posterior sacroiliac ligaments. Additional stabilization of the posterior ring is provided by the sacrotuberous and sacrospinous ligaments. The posterior ring structures are responsible for the majority of pelvic ring stability, whereas the symphyseal ligaments, which hold the pubis together, account for only 15% of the stability to the entire ring.364 These ligaments are responsible for anterior stability. It is important to understand the structures that are affected with differing pelvic ring injuries such that appropriate treatment plans can be made (Figs. 46-33A, B). 
Figure 46-33
Schematic drawing showing ligamentous structures of the pelvis with the left transparent hemipelvis.
 
A: Anterior view—ligaments intact on right side, with the sacrospinous and iliolumbar ligament (lumbosacral band) removed on left side for better visualization of underlying structures (sacrotuberous, lateral coccygeal and full visualization of anterior sacroiliac ligaments). B: Posterior view—ligaments intact on right side, with the long posterior sacroiliac and sacrotuberous ligaments removed on left side for better visualization of underlying structures (sacrospinous, interosseous sacroiliac, and short posterior sacroiliac ligaments).
 
(Primal pictures 3D software utilized to create image; Copyright Primal Pictures 3D)
A: Anterior view—ligaments intact on right side, with the sacrospinous and iliolumbar ligament (lumbosacral band) removed on left side for better visualization of underlying structures (sacrotuberous, lateral coccygeal and full visualization of anterior sacroiliac ligaments). B: Posterior view—ligaments intact on right side, with the long posterior sacroiliac and sacrotuberous ligaments removed on left side for better visualization of underlying structures (sacrospinous, interosseous sacroiliac, and short posterior sacroiliac ligaments).
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Figure 46-33
Schematic drawing showing ligamentous structures of the pelvis with the left transparent hemipelvis.
A: Anterior view—ligaments intact on right side, with the sacrospinous and iliolumbar ligament (lumbosacral band) removed on left side for better visualization of underlying structures (sacrotuberous, lateral coccygeal and full visualization of anterior sacroiliac ligaments). B: Posterior view—ligaments intact on right side, with the long posterior sacroiliac and sacrotuberous ligaments removed on left side for better visualization of underlying structures (sacrospinous, interosseous sacroiliac, and short posterior sacroiliac ligaments).
(Primal pictures 3D software utilized to create image; Copyright Primal Pictures 3D)
A: Anterior view—ligaments intact on right side, with the sacrospinous and iliolumbar ligament (lumbosacral band) removed on left side for better visualization of underlying structures (sacrotuberous, lateral coccygeal and full visualization of anterior sacroiliac ligaments). B: Posterior view—ligaments intact on right side, with the long posterior sacroiliac and sacrotuberous ligaments removed on left side for better visualization of underlying structures (sacrospinous, interosseous sacroiliac, and short posterior sacroiliac ligaments).
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The biomechanics of the pelvic ring are also important to understand to aid in treatment decisions. Because the axial skeleton is off axis relative to the SI joints and acetabula, the forces on the pelvic ring vary according to load, principally, either single-leg or bilateral-leg stance. When a person stands on both legs, both the symphysis and inferior SI joints are under tension, whereas the superior aspect of the SI joint is under compression. During a single-leg stance, the symphysis actually undergoes compression and VS while the SI joint forces flip, with compression inferiorly and tension superiorly.364 These stresses are noted in the intact pelvis. When ligaments are injured, there is an alteration in the directional forces. If the symphysis is disrupted, but the posterior ligamentous complex is intact, the symphysis will close, that is, compressional forces prevail, hence the rationale for nonoperative management of an APC I injury. The diastasis has been noted to close down over time with mobilization. When the anterior SI ligaments are disrupted in addition to the symphyseal injury, there continues to be tension on the symphysis resulting in further widening with weightbearing. Surgical intervention is then warranted. 
These ligaments not only support the bony pelvis but also the soft tissue structures contained within the pelvis. With disruption of the ligaments, and thus the pelvic ring integrity, there can be hemorrhage from both venous and arterial vessels. Notably the venous plexus is almost always injured to some extent with pelvic disruption. The internal iliac vessels and its major trunks pass anterior to the SI joints (Fig. 46-34) and then exit the pelvis through the greater and lesser sciatic notches and the obturator foramen. The superior gluteal vessels exit the greater sciatic notch and are frequently involved. 
Figure 46-34
Schematic drawing showing the neurovascular vascular structures within the pelvis.
 
The left hemipelvis is visualized with a transparent sacrum and L5 body. The internal iliac branches are seen anterior to the SI joint. The proximity of the bladder and urethra to the symphysis is appreciated. The nerve roots exiting the foramen are demonstrated with the L5 nerve root anterior on the sacral ala.
 
(Primal pictures 3D software utilized to create image; Copyright Primal Pictures 3D)
The left hemipelvis is visualized with a transparent sacrum and L5 body. The internal iliac branches are seen anterior to the SI joint. The proximity of the bladder and urethra to the symphysis is appreciated. The nerve roots exiting the foramen are demonstrated with the L5 nerve root anterior on the sacral ala.
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Figure 46-34
Schematic drawing showing the neurovascular vascular structures within the pelvis.
The left hemipelvis is visualized with a transparent sacrum and L5 body. The internal iliac branches are seen anterior to the SI joint. The proximity of the bladder and urethra to the symphysis is appreciated. The nerve roots exiting the foramen are demonstrated with the L5 nerve root anterior on the sacral ala.
(Primal pictures 3D software utilized to create image; Copyright Primal Pictures 3D)
The left hemipelvis is visualized with a transparent sacrum and L5 body. The internal iliac branches are seen anterior to the SI joint. The proximity of the bladder and urethra to the symphysis is appreciated. The nerve roots exiting the foramen are demonstrated with the L5 nerve root anterior on the sacral ala.
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Disruption of the pelvic ring, either through ligamentous disruption or fractures, requires a significant force. Many visceral structures are intimately associated with the bony pelvis and are often injured. Urologic injuries occur with pelvic ring injuries due to the bladder and urethra being immediately posterior to the pubic symphysis (Fig. 46-34). Scrotal hematomas and vaginal lacerations also occur with pelvic trauma because of their proximity to the symphysis. Because the rectum is immediately anterior to the sacrum, injury can occur. 
Neurologic injuries can also occur in association with pelvic ring injuries. The L5 nerve root lies on the anterior aspect of the sacral ala and is at risk with pelvic ring fractures or during surgical intervention. The sacral nerve roots exit from each of the five sacral foramina. These coalesce to form part of the lumbosacral and all of the sacral plexus, which innervate the perineal structures and lower extremities. The nerve roots can be injured with sacral fractures, and in Zone II injuries may require decompression if involved. The primary named peripheral nerves that exit the pelvis via the greater sciatic notch are the sciatic nerve, the superior and inferior gluteal nerves, and the internal pudendal nerve. The obturator nerve exits the pelvis via the obturator foramen (Fig. 46-34). 
Pelvic ring injuries ultimately require a multidisciplinary approach for management because of the associated injuries to other organ systems. A full understanding of pelvic anatomy is required to treat these fractures, to prevent iatrogenic injuries, and to provide the best results. These associated neurologic, thoracic, and abdominal visceral injuries have been shown to be more predictive than the pelvic ring fracture itself in determining mortality and functional outcome.59,65,252 Early consultation with urologists and general surgeons is paramount. 

Overview of Surgical Approaches for Pelvic Ring Fractures

The pelvis is generally approached from either an anterior exposure or posterior exposure depending on the injury being addressed. Percutaneous techniques are common and have been useful in the management of pelvic ring injuries. Surgical approaches are described in detail in each respective section on specific surgical technique. 
Anterior ring injuries require anterior approaches. The Pfannenstiel approach is the workhorse for an anterior approach to the treatment of symphyseal injuries. Additionally, a vertical midline approach can often be used in conjunction with trauma surgery when an exploratory laparotomy is indicated and/or pelvic packing is needed. If associated acetabular injuries or high rami fractures need to be addressed, the Stoppa approach can be useful. Percutaneous methods requiring minimal exposure can be also be used to address anterior ring injuries. 
The posterior ring can be accessed using anterior or posterior approaches. The posterior approach is generally the most direct approach to the SI joint, but the lateral window of the ilioinguinal approach (alternatively considered the proximal limb of the Smith-Pedersen approach) can be also used to repair SI joint dislocations. This approach allows for direct reduction and fixation with plates as well as decompression of the L5 nerve root in the event of entrapment in the SI joint or the sacral fracture. Iliac wing fractures and select crescent fractures can be managed using this anterior or posterior approach, depending on fracture location and configuration. However, all lumbopelvic disassociations should be managed with a posterior approach as is the case for sacral fractures requiring open reduction and internal fixation or sacral root decompression. 

Treatment Options for Pelvic Ring Fractures

Nonoperative Treatment of Pelvic Ring Fractures

Careful evaluation of the patient, preoperative plain radiographs, and a CT scan can help determine the need for surgical intervention in pelvic ring fractures. Many pelvic ring fractures can be treated nonoperatively given the right conditions. The following injuries are amenable to nonsurgical management: (a) Stable pelvic ring injuries, (b) stable sacral injuries, (c) comorbidities precluding surgical intervention, (d) poor bone quality where screw purchase may be problematic, and (e) the low-energy osteoporotic pelvic ring fracture. The most common stable pelvic ring injury is the LC I, which can be treated nonoperatively. In a retrospective review, serial radiographs of patients with lateral compression pelvic ring fractures were evaluated for displacement. The authors found that incomplete lateral compression sacral fractures with ipsilateral rami fractures were unlikely to displace. In addition, 15 of 22 (68%) complete sacral fractures combined with bilateral rami fractures displaced, and 33% of complete sacral fractures with unilateral rami fracture displaced.31 Patients with fractures of the rami anteriorly with complete sacral fractures are at risk for displacement. 
As our population ages, there has been an increase in low-energy osteoporotic pelvic ring injuries.161,272 The previously described classification system, for fragility fractures of the pelvis, by Rommens and Hoffman,270 provides recommendations for treatment. The FFP type I nondisplaced fractures can often be managed nonoperatively. As an adjunct to nonoperative fracture management, parathyroid hormone has been shown to be useful.213,235 In a randomized controlled trial,235 21 patients were given a daily injection of 100 micrograms of PTH 1–84 with a control group of 44 patients. All patients received vitamin D and calcium. The treatment group had significant improvement in both pain, as measured by the visual analogue scale (VAS), and the Timed “Up and Go” test. Union rates were significantly improved in the PTH group (100% vs. 9.1%). 
Historically, weightbearing was limited to toe touch on the side of the sacral fracture with repeat imaging after the patient had ambulated with a walker or crutches, with the weight-bearing restriction maintained for 6 to 12 weeks. Over time, it has become evident that these fractures can be progressed to weightbearing as tolerated (WBAT) as the patient’s pain subsides. To ensure pelvic stability, repeat radiographic evaluation should be undertaken after the patient mobilizes. 

Treatment-Specific Outcomes

There are very few studies looking at the functional outcome of single type of pelvic ring fracture. In addition most outcome studies focus on surgical treatment as opposed to nonsurgical management. Siebler et al.300 reported the functional outcomes of a small consecutive series of 11 patients treated nonoperatively for Denis Zone III sacral fractures that were in essence lumbopelvic disassociation injuries. Six fractures were Roy-Camille type 2 fractures and five were type 1 fractures. At a minimum of 2-year follow-up, all fractures healed, but mean SF-36 scores were lower than in the general population, and 73% of patients still had residual bowel, bladder, or sexual dysfunction. The majority of patients did show improvement in neurologic findings over time. 

Operative Treatment of Pelvic Ring Fractures

Current Treatment Options

Surgical treatment of pelvic ring fractures is best performed by a fellowship-trained orthopaedic traumatologist. The procedures, albeit straightforward with appropriate training, can be overwhelming and create great anxiety for any orthopaedic surgeon regardless of experience. The surgical anatomy is complicated and the pelvis a very “3D structure” with the usual AP and lateral images inadequate in the evaluation of such injuries. Significant experience is required to appropriately evaluate the patient and the pelvic ring injury with the aforementioned imaging modalities. To operate or not to operate as well as which approach to utilize—anterior, posterior, or both—are the main decisions that must be made; this is the most crucial step. There are some basic tenets in pelvic ring fracture management that can aid the orthopaedic traumatologist in determining the need for surgery as well as the type of fixation and the order in which to proceed (anterior vs. posterior). The indications for anterior ring stabilization (Table 46-5) are as follows:187 
 
Table 46-5
Indications for Anterior Ring Stabilization
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Table 46-5
Indications for Anterior Ring Stabilization
Symphyseal dislocations demonstrating >2.5 cm of diastasis on either static or dynamic (examination under anesthetic) imaging, indicating a rotationally unstable but vertically stable pattern
Augmentation of posterior fixation in vertically displaced unstable pelvic ring injuries
Augmentation of posterior fixation in completely unstable pelvic ring injuries
To augment poor posterior fixation in osteopenic bone
Significantly displaced rami fractures
Locked symphysis
Straddle fractures (bilateral superior and inferior rami fractures)
Pain and inability to mobilize (relative indication)
X
It is important to note that in fractures associated with bladder ruptures, internal fixation may be contraindicated despite the preceding indications, and external fixation may be the technique of choice. If anterior fixation is indicated, it is imperative that communication with the general surgeon and urologist be maintained if colostomy or suprapubic catheter placement is contemplated. Poor placement of either may also prevent appropriate incisions for internal fixation. 
The posterior ring injury can involve one of three areas or any combination thereof: (a) A ligamentous injury to the SI joint, (b) a sacral fracture, or (c) an iliac wing fracture. Stabilization of the posterior ring probably causes the most angst among surgeons because of the potential neurovascular structures at risk during surgical intervention. The relative indications for posterior ring stabilization (Table 46-6) are as follows: 
 
Table 46-6
Relative Indications for Posterior Ring Stabilization
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Table 46-6
Relative Indications for Posterior Ring Stabilization
Complete disruption of the SI joint and anterior and posterior SI ligaments, resulting in multiplanar instability
Any posterior ring injury, SI dislocation, or sacral fracture with vertical displacement or the propensity to do so
Displaced crescent fractures—displaced iliac wing fractures that enter and exit both the crest and greater sciatic notch or SI joint
Complete sacral fractures with the potential for displacement
Displaced sacral fractures
Lumbopelvic disassociation
 

SI, sacroiliac.

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Sacral fractures deserve special consideration because they can be considered a part of a larger pelvic ring injury or in isolation as a spinal injury with or without neurologic compromise, or both. The sacrum articulates with each hemipelvis to form the sacroiliac joints on each side, thereby serving as the “keystone” for the posterior ring and its connection between the pelvis and the spine. Therefore, all forces are transmitted between the lower extremities and the torso through the sacroiliac and L5-S1 facet joints. The management of sacral fractures is challenging due to the uniqueness of these relationships between the hemipelvis, sacrum, and spine. Furthermore, the care of these fractures is complicated by their close association with critical neurovascular structures, which are at risk during surgical procedures. The appropriate treatment depends largely on careful analysis of the sacral fracture pattern, neurologic involvement, and associated pelvic ring disruption. It is crucial to ensure that the lumbopelvic junction is stable and to address any associated neurologic injury. 
The VS fractures of the sacrum result in disruption of the posterior pelvis. H-shaped or U-shaped sacral fractures are bilateral transforaminal vertical fractures joined by a transverse fracture line. The level of the transverse line determines the “H” or “U” configuration. These injuries result in the so-called lumbopelvic disassociation, which rarely disrupts the ring structure. There can be associated and variable degrees of injury of the L5-S1 facet joint with cephalad extension of the fracture resulting in instability.66 The neurologic deficit may be in the form of a true cauda equina lesion, in the case of lumbopelvic disassociation with the transverse or U-shaped sacral fracture,108,293 or a unilateral peripheral nerve root injury, most often associated with VS fractures.66 
The sacrum is an important structure to consider in the treatment of pelvic ring fractures, as it is part of the posterior pelvic complex. The sacral fracture may or may not require fixation depending on the severity of the fracture, type of fracture, and the amount of displacement and neurologic involvement. The impacted lateral compression fracture, albeit vertical in nature, is often incomplete and inherently stable. These most often do not require operative fixation. Additional indications for the reduction and stabilization of the sacral fracture component of the posterior ring injury or spinopelvic disassociation are seen in (Table 46-7). 
 
Table 46-7
Indications for Sacral Fracture Stabilization
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Table 46-7
Indications for Sacral Fracture Stabilization
Vertical shear sacral fracture posteriorly and a concomitant anterior ring injury is present
Comminuted sacral alar fractures with external rotation deformity of the hemipelvis
Lumbopelvic disassociation injury
Lateral compression fractures with sacral impaction and excessive internal rotation
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If the vertical sacral fracture is displaced, longitudinal traction is required to obtain the reduction (Fig. 46-35A–C). Reestablishment of the height of the hemipelvis can be a challenge, but the AP view should be evaluated to ensure that the iliac crests, acetabular domes, and the ischial tuberosities are at the same levels bilaterally. Once the pelvis is brought back down caudal to its proper height, medial translation is required to reduce the fracture gap that usually has occurred. This is done with reduction clamps through a posterior incision if it is large. Percutaneous SI lag screw fixation can be used in cases where there is minimal gapping and no rotational or translational forces to stabilize the injury. Nonunions may occur if there is residual distraction286 (Fig. 46-36), and maximum stability is achieved when there is anatomic reduction of the fracture.260 If there is severe comminution in a Zone II injury or at the sacral ala, caution must be taken during reduction and stabilization to avoid inadvertent L5 or sacral nerve root injury. 
Figure 46-35
Patient with vertical shear pelvic ring injury.
 
A: Outlet view showing cephalad displacement of right hemipelvis (white bars) with arrow showing avulsion fracture of L5 transverse process fracture. B: Longitudinal traction view showing vertical reduction of right hemipelvis (straight bar across symphysis). C: Postoperative view after reduction and stabilization with ORIF of symphysis and iliosacral screw fixation of right SI joint (bars showing level iliac crests and ischial tuberosities).
A: Outlet view showing cephalad displacement of right hemipelvis (white bars) with arrow showing avulsion fracture of L5 transverse process fracture. B: Longitudinal traction view showing vertical reduction of right hemipelvis (straight bar across symphysis). C: Postoperative view after reduction and stabilization with ORIF of symphysis and iliosacral screw fixation of right SI joint (bars showing level iliac crests and ischial tuberosities).
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Figure 46-35
Patient with vertical shear pelvic ring injury.
A: Outlet view showing cephalad displacement of right hemipelvis (white bars) with arrow showing avulsion fracture of L5 transverse process fracture. B: Longitudinal traction view showing vertical reduction of right hemipelvis (straight bar across symphysis). C: Postoperative view after reduction and stabilization with ORIF of symphysis and iliosacral screw fixation of right SI joint (bars showing level iliac crests and ischial tuberosities).
A: Outlet view showing cephalad displacement of right hemipelvis (white bars) with arrow showing avulsion fracture of L5 transverse process fracture. B: Longitudinal traction view showing vertical reduction of right hemipelvis (straight bar across symphysis). C: Postoperative view after reduction and stabilization with ORIF of symphysis and iliosacral screw fixation of right SI joint (bars showing level iliac crests and ischial tuberosities).
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Figure 46-36
Patient with nonunion of sacral fracture and hardware failure with distraction (comminution) at time of iliosacral fixation.
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When treating pelvic ring injuries, it is important to keep the following general principles in mind: 
  1.  
    The posterior injury is regarded as the more critical one, requiring an accurate reduction and maintaining it with stable fixation.
  2.  
    If there is complete instability of the posterior ring, anterior fixation can neither maintain posterior reduction nor restore stability. This is true for internal fixation and even more so for external fixation. Complete instability of the posterior ring may be ligamentous SI joint disruption or displaced sacral fractures.
  3.  
    If there is associated cephalad displacement of the hemipelvis with complete instability of the posterior ring, posterior fixation should always be supplemented with anterior stabilization (ORIF or external fixation).328 Fixation of the symphysis pubis has been shown to be critical in restoring normal loading response and stability to the unstable hemipelvis.287 This is despite the pubic symphysis providing only 10% to 15% of the stability to the intact pelvic ring.128,364
  4.  
    In general, the posterior pelvic ring should be reduced and stabilized first, followed by reduction and stabilization of the anterior pelvic ring.172,176 Although some controversy exists, with anterior fixation followed by posterior fixation by some when the symphyseal injury is unilateral with an intact innominate bone.162

External Fixation

Anterior external fixation of the pelvis can be undertaken for the uncommon isolated anterior ring injuries, such as bilateral rami fractures (Straddle injury), or for rotationally unstable injuries involving the anterior and posterior ring. The decision to first perform anterior external fixation may be for one of the following reasons: (a) As an emergent procedure to reduce pelvic volume and restore hemodynamic stability or (b) to reduce the posterior lesion prior to posterior stabilization. Anterior external fixation can also be performed after posterior stabilization to neutralize and augment the posterior fixation, as well as in cases requiring prone positioning. The use of external fixation in isolation has been problematic in unstable pelvic ring fracture patterns, with high rates of loss of reduction and subsequent malunions.177 
Surgical Technique.
The classic placement for an anterior external fixator involved fixation into the iliac crest. Traditionally either two or three 5-mm partially threaded Schanz pins have been used in each crest,249 but a simple one-pin (in each crest) two-bar fixator has been used effectively in definitive cases.353 Smaller Schanz pins are weaker30 and larger pins usually cannot be accommodated within the ilium. Pins are placed using small incisions approximately 2 to 3 cm posterior to the anterior superior iliac spine (ASIS) to minimize injury to the lateral femoral cutaneous nerve. They are placed into the iliac wing and directed toward the supra-acetabular region for the best chance of solid fixation (Fig. 46-37). The small incisions should be used to allow palpation of the inner table to ascertain the proper trajectory for the pin. Either finger palpation or even placement of a K-wire against the inner table can aid in the trajectory. Incisions may need to be extended in cases of severe displacement of the pelvis or in obese individuals. After reduction, incisions may need to be “relaxed” if there is any tension on the skin. 
Figure 46-37
Emergent external fixation for open pelvic ring fracture with two “traditional” pins placed in each iliac crest.
 
The red shaded areas represent the supra-acetabular bone in which the pins should end.
The red shaded areas represent the supra-acetabular bone in which the pins should end.
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Figure 46-37
Emergent external fixation for open pelvic ring fracture with two “traditional” pins placed in each iliac crest.
The red shaded areas represent the supra-acetabular bone in which the pins should end.
The red shaded areas represent the supra-acetabular bone in which the pins should end.
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At this point a triple soft tissue sleeve is utilized, and the trocar is placed directly onto the crest. The trocar is removed and a drill bit is used to create a pilot hole. The Schanz pin is then placed manually and allowed to find its way between the inner and outer tables. If possible, the pin should end short of the acetabulum in the thick supra-acetabular bone. A second pin can be placed posterior along the crest but in a convergent manner. If a multipin clamp is used, both the location and direction of the pin are often predetermined. The surgeon must be familiar with the instrumentation of the external fixation system being used and as to what options are available in terms of rods and clamps. 
The same procedure is performed on the contralateral side. Pin to bar clamps or multipin clamps are used, and then a single bar to bar clamp to connect the two rods. The pelvis is reduced by direct pressure on each hemipelvis—the pins should not be used as a joystick and manipulated as reduction tool as the pins may fracture out of the narrow ilium. Connections are tightened once reduction is achieved. External fixation is now complete. 
Hannover Surgical Technique.
Recently a two-pin construct utilizing Schanz pin placement into the supra-acetabular bone has been described.87,245 This construct is being advocated more and more,92,123 as these pins are biomechanically superior.79 Small incisions are used to place these pins. The plentiful bone in the supra-acetabular region is used, and the pins are directed toward the posterior inferior iliac spine into the thick bone of the sciatic buttress. Advantages of this technique are the following: (a) Placement of pins below the abdomen and the external fixation construct is out of the way of abdominal procedures, (b) two pins are sufficient (one on each side), (c) fixation is excellent, (d) allows for the direction of closure of an open-book injury in the same plane and thus better control,68 and (e) biomechanically superior in resisting rotational forces and equal to an iliac crest frame in resisting flexion and extension7,152,251 (Fig. 46-38). A disadvantage is that this two-pin construct is more dependent on the use of intraoperative fluoroscopy for placement of the pins. 
Figure 46-38
 
Patient with pelvic ring fracture where the anterior injury was stabilized with a two-pin anterior supra-acetabular fixator.
Patient with pelvic ring fracture where the anterior injury was stabilized with a two-pin anterior supra-acetabular fixator.
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Figure 46-38
Patient with pelvic ring fracture where the anterior injury was stabilized with a two-pin anterior supra-acetabular fixator.
Patient with pelvic ring fracture where the anterior injury was stabilized with a two-pin anterior supra-acetabular fixator.
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To place supra-acetabular pins, the c-arm is used to determine the appropriate starting point, which is usually about two finger-breadths below the ASIS and is easily palpable in slim individuals. In the obese individual, the accurate starting point can be difficult to ascertain and thus fluoroscopy is helpful. An obturator-outlet view of the acetabulum on the side of fixation is obtained. This view is generally at the 45-45-degree position to start with but is adjusted in both planes as necessary to obtain the “teardrop” view (Fig. 46-39). The author utilizes the handle end of a hemostat directly over the teardrop to mark the skin. This is the area for the skin incision. The teardrop itself is a radiographic representation of the inner and outer tables of the ilium and the top of the greater sciatic notch inferiorly. The center is the column of bone through which fixation is desired and extends from the anterior iliac spine to the posterior inferior iliac spine as seen on an iliac oblique view. 
Figure 46-39
Obturator outlet view, “Teardrop” view obtained via fluoroscopy.
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The skin is incised in a slight oblique fashion, so as to prevent any potential tenting of the skin from the shaft of the pin, but often skin releases are needed after reduction of the pelvis is obtained. A triple soft tissue sleeve is used from the external fixator system, and the sharp trocar is placed down directly onto the anterior inferior iliac spine (AIIS) angled toward the sciatic buttress. The trocar is removed and an appropriate sized drill bit for the external fixation system being used creates a pilot hole. There is no need to drill the entire depth and in fact it is safer to allow the Schanz pin “to find its way” while visualizing under intraoperative fluoroscopy. Manual advancement is preferred, but a power drill may be used under experienced hands. The c-arm should be positioned for an iliac oblique view of the operative side while the pin is being placed (Fig. 46-40A–C). The tip of the Schanz pin should either end in the sciatic buttress bone to avoid far cortical penetration and prevent any potential injury to the structures exiting the greater sciatic notch or it can be directed toward the posterior inferior iliac spine (PIIS) (Fig. 46-40C). In a similar fashion the opposite side Schanz pin is placed. Reduction of the pelvis may have already occurred via posterior fixation; if the frame is used for reduction purposes the pins may be used to close the pelvis, but in general application of force to the hemipelvis itself through the lateral aspect is preferred to avoid ripping out pins. Pin to bar clamps are applied and two bars with a bar to bar clamp are used to connect the two pins. All connections are tightened while the reduction is being held. External fixation is now complete. 
Figure 46-40
Sequential imaging for placement of supra-acetabular pin.
 
A: Soft tissue guide and trocar on AIIS. B: Advancement of drill. C: Placement of Schanz pin (supra-acetabular area of bone in red shaded area stopping short or greater sciatic notch; arrow showing that trajectory of pin can also be from AIIS to PIIS).
A: Soft tissue guide and trocar on AIIS. B: Advancement of drill. C: Placement of Schanz pin (supra-acetabular area of bone in red shaded area stopping short or greater sciatic notch; arrow showing that trajectory of pin can also be from AIIS to PIIS).
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A: Soft tissue guide and trocar on AIIS. B: Advancement of drill. C: Placement of Schanz pin (supra-acetabular area of bone in red shaded area stopping short or greater sciatic notch; arrow showing that trajectory of pin can also be from AIIS to PIIS).
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Figure 46-40
Sequential imaging for placement of supra-acetabular pin.
A: Soft tissue guide and trocar on AIIS. B: Advancement of drill. C: Placement of Schanz pin (supra-acetabular area of bone in red shaded area stopping short or greater sciatic notch; arrow showing that trajectory of pin can also be from AIIS to PIIS).
A: Soft tissue guide and trocar on AIIS. B: Advancement of drill. C: Placement of Schanz pin (supra-acetabular area of bone in red shaded area stopping short or greater sciatic notch; arrow showing that trajectory of pin can also be from AIIS to PIIS).
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A: Soft tissue guide and trocar on AIIS. B: Advancement of drill. C: Placement of Schanz pin (supra-acetabular area of bone in red shaded area stopping short or greater sciatic notch; arrow showing that trajectory of pin can also be from AIIS to PIIS).
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Distraction External Fixation.
A special hybrid modification by Evans et al.,77 the “oblique distraction external fixator,” requires special mention. This utilizes one pin placed in the iliac crest (as described earlier) and an opposite pin placed in the supra-acetabular region (as described earlier). The mismatch in pin trajectories allows the frame to be used for the lateral compression pelvic ring disruptions, which have associated flexion deformities in addition to the internal rotation. Once the pins are applied, either the large femoral distractor (DePuy Synthes) or the large external fixator rods with a compression/distractor device can be used to obtain the reduction. The obliquity of the frame allows for an external rotation force and extension force to be applied simultaneously. This does require an incomplete posterior pelvic ring injury, which acts as the hinge. It can be used, as any other external fixator, as definitive treatment, as an adjunct to internal fixation, or as a reduction tool after which internal fixation is applied and then the fixator removed. 
Postoperative Care.
External fixation requires additional postoperative care with respect to pin care. The author uses Kerlix gauze wraps only without additional use of peroxide or saline. Patients may shower after any additional incisions for other operative interventions have healed, which is generally 2 weeks postoperatively. The pins may be unwrapped before showers and soap and water allowed to run onto the pin sites. The pin sites are then dried and wrapped to fill in the gap between the skin and the bottom of the pin clamp. This is done to minimize skin motion around the pin site, which we feel contributes to pin-site infection. If a superficial pin-site infection occurs, generally a 10 to 14 day course of oral antibiotics and continued pin care will resolve it. Deeper infection, which may be exhibited by gross purulence and even loosening on a plain radiograph, may require more aggressive surgical debridement, intravenous antibiotics, and possible revision. 
Potential Pitfalls and Preventive Measures.
Iliac Crest Frame
Perforation of the inner table into the internal iliac fossa, or the outer table into the gluteal musculature is not uncommon (Fig. 46-41). This occurs predominately with the traditional iliac crest pins and frames. The iliac wing is thin, and attempts at placement of two or three pins often results in frequent perforation into the internal iliac fossa150,197,353 as well as suboptimal fixation. Often the trajectory of such pins is directed into the thin position of the iliac wing as opposed to being directed down toward the acetabulum. The wing itself is extremely thin and perforation occurs. To prevent this, finger palpation or placement of a K-wire onto the surface of the inner table can guide the surgeon. Aiming toward the opposite greater trochanter while taking into consideration the trajectory of the wing will allow for proper placement and minimize perforation and poor fixation. 
Figure 46-41
CT scan after placement of ex-fix showing perforation of outer ilium with Schanz pin (red circle).
Rockwood-ch046-image041.png
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Injury to the lateral femoral cutaneous nerve may occur if the incision is not posterior on the crest. Injury to the bowel can occur with poor trajectory. Penetration into the joint can occur without proper intraoperative visualization. 
Hannover Frame
Intraoperative fluoroscopy should be used when placing Schanz pins to avoid (a) penetration of the acetabulum,315 (b) penetration into the sciatic notch, and (c) penetration anterior or posterior. The starting point should be determined by obtaining the “teardrop” view, and confirmation of placement of the pin should occur with the same view (Fig. 46-42). The pin should always be advanced under the iliac oblique view so as to ensure that the greater sciatic notch is not violated (Fig. 46-40A–C). 
Figure 46-42
 
Fluoro view showing placement of supra-acetabular pin in right side—note “misfire” hole from first attempt (red arrow).
Fluoro view showing placement of supra-acetabular pin in right side—note “misfire” hole from first attempt (red arrow).
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Figure 46-42
Fluoro view showing placement of supra-acetabular pin in right side—note “misfire” hole from first attempt (red arrow).
Fluoro view showing placement of supra-acetabular pin in right side—note “misfire” hole from first attempt (red arrow).
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Treatment-Specific Outcomes.
Cole et al.,49 comparing anterior external fixation to an anterior internal fixator technique utilizing plates and screws, reported higher incidences of wound complications and overall morbidity with the external fixation group. In addition, external fixation patients reported higher surgical site pain that persisted through follow-up. Pin-site infections are common, occurring anywhere from 2% to 50%.177 
Internal External Fixator—New Technique (Off-Label).
Recently there has been interest in using an internal external fixator in place of the anterior external frame. The supra-acetabular position of Schanz pins is replaced with the use of pedicle screws. Vaidya et al. reported the first use of such a device, termed INFIX, by adapting spinal instrumentation to the pelvis (off-label use).355 Indications in their series were for vertically unstable pelvic ring fractures after which posterior stabilization was performed, windswept injuries (LC III) after posterior fixation, for distraction of the anterior injury in lateral compression fractures, open-book injuries for which ORIF was less desirable, and conversion from “temporary external fixation” in unstable patients to a more definitive fixation. The internal external fixator was not used in the acute case, and was initially designed for obese patients, but through their series, they began adapting the technique to normal-sized individuals. The authors reported minimal complications, most of which were associated with the supra-acetabular fixation and its proximity to the lateral femoral cutaneous nerve. Gardner et al. published their experience with this technique, and used it in cases to augment posterior fixation by stabilizing the anterior ring injury. They reported similar results and complications, adding the finding of Grade I heterotopic ossification (HO) at the screws sites. Operative removal is required, which is a disadvantage compared to many external fixators, which can be removed in the clinic. 
A variation of the internal external fixator has been described in which pelvic reconstructive plates (14 to 18 hole) and 3.5 mm screws are utilized. Cole et al.49 in their retrospective chart review, reported fewer wound complications, lower overall morbidity, and a lower rate of surgical site pain when compared to the anterior external fixation group (pins applied to the iliac crest). Indications were similar and pelvic reduction was maintained in both groups. The plate runs from one ASIS to the other along the anterior aspect of the pelvic ring. Screws are applied to each ASIS, as well as to the symphysis, and thus this uses three separate incisions for placement. Although, hardware removal was routinely performed in their series, the potential advantage of a plate “internal fixator” could be retention. Despite the additional technical requirements and surgical approach of utilizing a plate, an anatomic study reported that the crucial structures evaluated were not at significant risk.203 
Surgical Technique.
NOTE: This procedure requires spinal instrumentation and thus is an off-label indication at the time of writing. Modifications of current spinal systems are underway by some companies to be pelvic specific. 
Patient positioning and prepping is the same as described previously. The posterior injury should be addressed first (see Posterior techniques). The surgeon should become familiar with the spinal system to be used. The starting point for the placement of the pedicle screws is similar to placement of supra-acetabular pins described previously. An anatomic study looking at the feasibility of such a technique emphasized that attention to the surgical technique can minimize potential risks.198 
A 2- to 3-cm incision is centered over the AIIS in an oblique transverse fashion in line with the groin crease. Blunt dissection is carried down through the soft tissues and the interval between the sartorius and tensor fascia lata is developed. This should allow direct access to the AIIS. A pedicle awl or an appropriately sized drill bit can be used to open the cortex. The iliac oblique view is then used, as described earlier, for placement of the pedicle screw. The length of the pedicle screw is determined with a pedicle finder, which is inserted into the cortical perforation created and depth visualized via c-arm. The measurement can be read directly off the pedicle finder. A pedicle screw that is 15 to 40 mm longer than what is measured should be placed to allow it to sit above the bone in the soft tissues so as to accept the end of a spinal rod. The additional length is based on the patient’s size. The opposite side pedicle screw is placed in the same way. The spinal rod should be contoured using the rod benders and cut to about 5 to 6 cm longer than the distance between the two pedicle screws. The rod is then tunneled subcutaneously from one screw to another. Connection to the pedicle screws is performed. The anterior pelvis can be closed anteriorly with use of compressor tools (if open-book pelvis injury; lateral compression injuries can conversely be distracted) that usually accompany the spinal instrumentation sets. Once reduction is achieved, the rods can be secured to the pedicle screws and locked into place (Fig. 46-43A–C). Next the excessive rod length can be removed in situ with a rod cutter, and the incisions can be irrigated and closed.355 
Figure 46-43
Morbidly obese patient with anterior InFix and posterior screw fixation.
 
A: AP. B: Inlet. C: Outlet (note broken guide wire for placement of cannulated pedicle screw right side).
A: AP. B: Inlet. C: Outlet (note broken guide wire for placement of cannulated pedicle screw right side).
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Figure 46-43
Morbidly obese patient with anterior InFix and posterior screw fixation.
A: AP. B: Inlet. C: Outlet (note broken guide wire for placement of cannulated pedicle screw right side).
A: AP. B: Inlet. C: Outlet (note broken guide wire for placement of cannulated pedicle screw right side).
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Postoperative Care.
Postoperative management does not require pin care as all fixation is internal. Removal has been advocated, although the timing has varied in each series reported, and some even declined removal without any ill effects.90,355 The hardware should be maintained at a minimum of 3 months, as that is the usual time for ligamentous healing, and then removed. Toe touch weight bearing restrictions are placed on the side of the injury, and advanced anywhere from 6 to 12 weeks, depending on the fracture pattern and healing progression. Sutures are removed at 2 weeks. 
Potential Pitfalls and Preventive Measures.
The same preventive measures should be applied in this procedure as with placement of supra-acetabular pins, namely the use of intraoperative c-arm fluoroscopy throughout the procedure. The pedicle screw should be maintained about 30 to 40 mm above the bone so as not to cause compression of crucial neurovascular (femoral nerve and/or artery) structures beneath it once the rod is attached.90,355 Minimizing soft tissue trauma around the screw insertion site may help to decrease the incidence of HO being reported (Fig. 46-44A, B). Because spine instrumentation is being adapted to the pelvis, the cannulated screw systems have been somewhat problematic for the dense supra-acetabular bone compared to the soft cancellous bone in the spine (Figs. 46-43 and 46-44). 
Figure 46-44
Patient with anterior InFix.
 
A: AP—note broken tap on left side of pelvis. B: AP after removal at 6-month follow-up showing HO (blue arrows).
A: AP—note broken tap on left side of pelvis. B: AP after removal at 6-month follow-up showing HO (blue arrows).
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Figure 46-44
Patient with anterior InFix.
A: AP—note broken tap on left side of pelvis. B: AP after removal at 6-month follow-up showing HO (blue arrows).
A: AP—note broken tap on left side of pelvis. B: AP after removal at 6-month follow-up showing HO (blue arrows).
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Treatment-Specific Outcomes.
In a multicenter study, complications reported included early revisions due to technical errors, irritation of the lateral femoral cutaneous nerve with subsequent resolution, and asymptomatic heterotopic ossification.356 In the two small single-center series published, all patients healed without loss of reduction. No deep infections or loosening of the device was reported. In one symptomatic case, the HO was debrided at time of hardware removal.90,355 

Surgical Procedures of the Anterior Pelvic Ring

Preoperative Planning and Positioning for Anterior Pelvic Ring Fixation.
Historically, anterior stabilization of the pelvis was approached predominately with external fixation. It was also used as an adjunct to posterior fixation in many cases. The procedure could be performed with relative ease by the majority of orthopaedists, was minimally invasive, and could treat both symphyseal diastasis and rami fractures.54 External fixation is not without its issues. It is cumbersome for the patient and can impede access to the abdomen required by the trauma surgeon. Pin-site complications, especially in the obese, and concerns with maintenance of reductions have tempered their use, especially as sole stabilization.10,100,186 Loosening of pins and poor fixation into the iliac wings had been problematic, but the use of supra-acetabular pins has improved fixation constructs.87,92,123,152,245 Although, biomechanical studies have shown that external fixation and internal fixation are equivalent for controlling external rotation in pelvic ring injuries,128,328 internal fixation is much better for controlling and resisting vertical displacement of the hemipelvis. In cases of VS pelvic ring fractures, significant improvement in pelvic ring stability occurs when the posterior fixation is augmented by anterior fixation.128,287 
With improvement in implant technology and increased comfort level of orthopaedic trauma surgeons in performing anterior surgical approaches, the use of internal fixation has increased. External fixation is still useful, especially in the situations where ORIF may be problematic, such as in abdominal compartment syndrome with an open contaminated laparotomy incision or bladder rupture where the fixation would be contaminated by urine. However, the determination of which surgical technique to employ should be based on many factors, including the condition of the patient and their soft tissues, associated injuries, the pattern of anterior injury (fracture and/or symphyseal disruption), biomechanical strength of fixation constructs, available implants, and the surgeon’s comfort level and skill. These techniques include anterior external fixators, the newly described “INFIX” (off-label use of spinal implants), formal open reduction and internal fixation with plates and screws, as well as percutaneous techniques, often reserved for rami fractures. Recently, the use of percutaneous screw fixation for symphysis diastasis was reported showing better functional outcome than standard ORIF techniques.44 An additional consideration in female patients of childbearing age is their potential plans for having children. Normal vaginal delivery requires relaxation of the pelvic ring, which may be hindered or prevented by residual internal fixation. The concern over the need for use of a cesarean section in patients with previous pelvic ring fractures has been raised.35 This, however, may be unfounded, as recent literature shows that normal delivery can occur even in the presence of internal fixation.357 
Careful evaluation of the plain radiographs and CT scans should be undertaken to determine if the planned surgical procedure can be accommodated by the patient’s pelvic structure. For example, is the column of bone large enough to handle the size of the screw planned (Fig. 46-45)? In addition, the coronal, sagittal, and 3D reconstructions can be useful for preoperative planning of one’s exposure and may alter the surgical plan. 
Figure 46-45
 
Coronal image of patient with pelvic ring injury showing anterior column of bone with smaller diameter than usual (approximately 4.6 mm).
Coronal image of patient with pelvic ring injury showing anterior column of bone with smaller diameter than usual (approximately 4.6 mm).
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Figure 46-45
Coronal image of patient with pelvic ring injury showing anterior column of bone with smaller diameter than usual (approximately 4.6 mm).
Coronal image of patient with pelvic ring injury showing anterior column of bone with smaller diameter than usual (approximately 4.6 mm).
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The patient should have a catheter in place to keep the bladder drained and decompressed. If a suprapubic catheter is placed, it should be placed well above the umbilicus by the urologist or trauma surgeon and away from the operating field (Fig. 46-46). Similarly, colostomies should be placed well above and out of the way of any potential anterior approach. Constant communication with and educating of both the trauma surgeons and urologists is helpful to avoid such potential problems. If a colostomy or suprapubic catheter is present, an occlusive dressing can be used to cover this area and sterile prep can be performed over it. Malplacement of either may force surgical stabilization alternatives that may not be optimum. If an external fixator is in place, the following several options exist and selection is dependent on the surgeon’s personal preference and experience: (a) Include the pins with or without the bars in the sterile prep and reapply a second prep once the drapes have been placed, (b) remove all of the components and cover the pin sites with occlusive dressing, or (c) remove rods and leave pins to aid in reduction maneuvers during the procedure. 
Figure 46-46
Patient with pelvic ring injury and associated bladder disruption.
 
Suprapubic catheter placed in poor position in direct way of Pfannenstiel incision (marked by dotted yellow line).
Suprapubic catheter placed in poor position in direct way of Pfannenstiel incision (marked by dotted yellow line).
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Figure 46-46
Patient with pelvic ring injury and associated bladder disruption.
Suprapubic catheter placed in poor position in direct way of Pfannenstiel incision (marked by dotted yellow line).
Suprapubic catheter placed in poor position in direct way of Pfannenstiel incision (marked by dotted yellow line).
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Positioning for anterior fixation is generally supine on a radiolucent table, preferably from head to toe. Supine positioning is usually not a problem even for the multiply injured patient. A general anesthetic is preferred to allow for adequate paralysis, which will aid in reduction. The Orthopedic System Incorporated (OSI, Union City, CA) flat-top table allows for adequate mobility of the c-arm underneath for inlet and outlet views without a base getting in the way. Regardless of the preference of operating room table, one must ensure that adequate images can be obtained on the table that is chosen. The patient should be placed flat without bumps under the hip to ensure that orientation of the pelvis is not altered. A small bump can be placed midline at the level of the normal lumbar lordosis to accentuate it. This increased extension of the pelvis can aid with screw placement. There are several methods for closed reduction of the open-book pelvic ring injury. A sheet can be placed around the patient at the level of the greater trochanters to aid in reduction if so desired. Another technique to reduce the open-book injury is internal rotation and taping of the lower extremities (IRTOTLE).94 All of these methods can simplify any intraoperative reduction maneuvers needed when the symphysis is exposed. These methods are especially useful for obtaining a closed reduction, if any vertically stable component is reduced as well, prior to placement of iliosacral screws. 
Surgical Approaches for Anterior Fixation.
The Pfannenstiel incision is the mainstay of anterior approaches for internal fixation of the pelvis. This incision is transverse and generally located about 2 cm, or two finger-breadths, above the symphysis pubis. The incision is typically about 6 to 8 cm in length in the transverse direction and in line with the “bikini line.” In obese patients, the location of the incision may be underneath the pannus and caution is needed because this area tends to be problematic.29 An alternative incision is one that is made midline, often used for exploratory laparotomy. However, it usually is not extended all the way down to the symphysis. If the trauma surgeon plans on doing a midline incision and the pelvic injury warrants anterior fixation, it is prudent to discuss a joint procedure with them and extension of their incision down to the symphysis. Planning and communication are required preoperatively, which can be challenging, especially if the patient is taken emergently to the operating room because of hemodynamic instability and intra-abdominal sources of bleeding. A midline incision for an exploratory laparotomy used by the trauma surgeon usually stops superior to the umbilicus, and thus in the event that a discussion did not occur prior to surgery, the author has performed a Pfannenstiel separately without skin bridge complications. 
At a minimum, the entire anterior pelvis from above the umbilicus to the top of the perineum and laterally on both sides to include the iliac crests and down around the gluteal region should be prepped (Fig. 46-47A). On occasion, one or both entire lower extremities may need to be prepped depending on the need for intraoperative traction/manipulation for reduction purposes. If a traction pin is in place in the lower extremity and desired/needed for the procedure, prep can be done to the mid-thigh and traction left in place to hang off the end of the bed. 
Figure 46-47
Patient undergoing anterior approach to symphysis for plating.
 
A: Pfannenstiel incision drawn out. Area prepped out from above umbilicus to perineum and down laterally on each side. B: Skin incision with exposed fascia. C: Longitudinal incision through fascia. D: Linea alba exposed confirming proper plane. E: Deep exposure showing symphysis and right ramus with malleable retractor protecting bladder. F: Final plate fixation.
A: Pfannenstiel incision drawn out. Area prepped out from above umbilicus to perineum and down laterally on each side. B: Skin incision with exposed fascia. C: Longitudinal incision through fascia. D: Linea alba exposed confirming proper plane. E: Deep exposure showing symphysis and right ramus with malleable retractor protecting bladder. F: Final plate fixation.
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Figure 46-47
Patient undergoing anterior approach to symphysis for plating.
A: Pfannenstiel incision drawn out. Area prepped out from above umbilicus to perineum and down laterally on each side. B: Skin incision with exposed fascia. C: Longitudinal incision through fascia. D: Linea alba exposed confirming proper plane. E: Deep exposure showing symphysis and right ramus with malleable retractor protecting bladder. F: Final plate fixation.
A: Pfannenstiel incision drawn out. Area prepped out from above umbilicus to perineum and down laterally on each side. B: Skin incision with exposed fascia. C: Longitudinal incision through fascia. D: Linea alba exposed confirming proper plane. E: Deep exposure showing symphysis and right ramus with malleable retractor protecting bladder. F: Final plate fixation.
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The skin is incised and dissection is carried down through the subcutaneous fat. At this point the rectus fascia will be encountered and the length of the incision can be gauged (Fig. 46-47B). The incision should run from one external inguinal canal to the other. This will allow the identification and protection of the spermatic cord in male patients and round ligament in female patients. In cases of significant symphyseal disruption, the rectus has been torn off usually on the side of the intact posterior structures. This allows for easy access, and the intact side can be taken down in a transverse fashion allowing exposure of the entire symphysis. Additional extension of the dissection laterally will increase exposure but again is limited by the reproductive structures. A more common approach is to develop this traumatic dissection vertically along the linea alba with minimal lateral dissection over the intact pubis. Either way, the traumatic tear in the rectus fascia must be repaired with nonabsorbable suture to prevent the development of subsequent hernias. If the rectus is completely intact, there are two options for continued exposure: (a) A transverse incision in the rectus at a level above the external inguinal canal but extended onto the external oblique aponeurosis allows a small anterior cuff of tissue to repair (similar to an ilioinguinal approach) or (b) the preferred method of a longitudinal incision in the linea alba down through the rectus musculature exposing the symphysis and the pubic bodies (Fig. 46-47C–E). In either exposure, dissection should not extend excessively anterior to the pubic bodies so as to avoid injury to the suspensory ligament of the penis or clitoris. 
At this point it does not matter whether the transverse exposure is used or the rectus is split longitudinally, as the deep dissection is similar. After splitting or lifting up the rectus fascia, the transversalis fascia is encountered, which often already has been torn. A blunt-ended self-retractor may be placed between the two rectus sheaths if a longitudinal split was used. Blunt dissection can be applied with a finger to allow access to the retropubic space of Retzius. Usually a large hematoma is encountered, which should be evacuated. The bladder should be carefully separated from the posterior aspect of the pubis. The Foley catheter can be palpated to help identify the bladder neck and urethra, which is useful because ideally the bladder has been successfully decompressed. Care must be taken to avoid inadvertent penetration of the peritoneal cavity. Remaining in intimate contact with the pubic rami during blunt dissection will aid in preventing intraperitoneal penetration. A large malleable retractor is placed to gently retract the bladder. Lap sponges may be placed behind the retractor, but this is not required and they may inadvertently be left in place. Excessive retraction resulting in pressure inferiorly can injure either the bladder neck or urethra and should be avoided. Once adequate exposure has been obtained and the hematoma evacuated, the retropubic space can be irrigated. 
Open reduction and internal fixation of the symphysis pubis requires sufficient exposure laterally over each superior ramus for placement of the plate. Dissection should extend anteriorly, until the superior medial aspect of the obturator foramen is encountered, and superiorly out lateral, in a subperiosteal fashion until the pubic tubercle is reached. This exposure should be carried out on both sides. Once adequate exposure is achieved, the symphyseal disruption can be reduced and fixed (Fig. 46-47F). 
For formal ORIF of rami fractures, the exposure over the superior aspect of the ramus must extend further laterally. A formal Stoppa329 approach can be performed as described. To aid in exposure, flexion of the hip with a bump placed underneath the knee will relax the neurovascular bundles, thereby minimizing the risk for injury, while a blunt-ended retractor is placed underneath the rectus and the neurovascular structures. Retraction of these structures should be done gently and with caution, as thrombosis of the vessels has been reported. The periosteum overlying the ramus can be incised sharply and peeled back with an AO or small Cobb elevator. At this point, it is paramount that, if present, the corona mortis is identified, isolated, and ligated prior to further dissection. This anastomotic connection between the external iliac and obturator vessels can bleed profusely and result in significant morbidity.347 The dissection can continue to the pubic root once ligation of the corona mortis if present and if needed has occurred (in cases of concomitant acetabular fractures through the quadrilateral surface) to the supra-acetabular bone of the inner table of the ilium. 

ORIF of Symphysis Diastasis

The surgical exposure for open reduction of the symphysis pubis has been described previously. If the patient’s injury is consistent with an open-book type injury, Young and Burgess APC II or III, where it is deemed necessary to perform ORIF of the symphysis diastasis, much of the reduction can be accomplished during positioning of the patient. In APC II or equivalent injuries with an intact posterior hinge, the reduction can often be anatomic (Fig. 46-48A, B). 
Figure 46-48
Patient with Zone II sacral fracture acting as APC II injury with intact posterior hinge.
 
A: Injury AP. B: AP after sheet placed showing near anatomic reduction of posterior lesion.
A: Injury AP. B: AP after sheet placed showing near anatomic reduction of posterior lesion.
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Figure 46-48
Patient with Zone II sacral fracture acting as APC II injury with intact posterior hinge.
A: Injury AP. B: AP after sheet placed showing near anatomic reduction of posterior lesion.
A: Injury AP. B: AP after sheet placed showing near anatomic reduction of posterior lesion.
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Surgical Technique.
A sheet is placed at the level of the greater trochanters and is wrapped circumferentially around the pelvis. Gardner et al93 has described this technique, whereby the sheet is wrapped entirely around the pelvis, in great detail with “windows” cut into the drape for iliosacral fixation. For purposes of ORIF of the symphysis, this is neither required nor desired. The sheet is kept at the level of the hips and wrapped, using hemostats or towel clamps to secure the sheet. This is done below the level at which the Pfannenstiel incision is made (Fig. 46-49). The approach is performed. 
Figure 46-49
 
Sheet placed preoperatively at the level of the greater trochanters still allowing for access to symphysis pubis for Pfannenstiel incision.
Sheet placed preoperatively at the level of the greater trochanters still allowing for access to symphysis pubis for Pfannenstiel incision.
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Figure 46-49
Sheet placed preoperatively at the level of the greater trochanters still allowing for access to symphysis pubis for Pfannenstiel incision.
Sheet placed preoperatively at the level of the greater trochanters still allowing for access to symphysis pubis for Pfannenstiel incision.
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Once the pubic bodies are exposed, several reduction instruments can be used to complete the reduction if the sheet failed to achieve complete reduction (often the case with completely unstable injuries; APC III or Tile C equivalents). The Jungbluth clamp has holes to allow for 3.5/4.5 mm screw placement into the anterior aspect of pubic body on each side, through which the clamp can be “fixed,” thereby allowing reduction to occur.190 (Fig. 46-50A–C). Alternatively, a Farabeuf clamp, which also allows utilization of screws (either 3.5 or 4.5 mm), can be used but is a little more cumbersome because of the exposure (Fig. 46-51A, B). This technique is often useful in cases where there may be additional sagittal plane rotation (flexion) and posterior translation, which often occurs in injuries with posterior ring involvement that require better control to obtain the reduction. Simple skeletal traction may resolve this deformity as well. The “screw” fixation allows for better multiplanar reduction maneuvers, as does a Schanz pin placed in the supra-acetabular area (see oblique distraction technique above). Attention must be taken to place these screws or any reduction forceps within the bone such that superior plate fixation is not impeded. 
Figure 46-50
Bony pelvic model showing screws placed in pubic tubercles anteriorly.
 
A: AP view with clamp in place. B: Anterior close-up view showing widened symphysis. C: Anterior close-up view showing reduced symphysis.
A: AP view with clamp in place. B: Anterior close-up view showing widened symphysis. C: Anterior close-up view showing reduced symphysis.
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Figure 46-50
Bony pelvic model showing screws placed in pubic tubercles anteriorly.
A: AP view with clamp in place. B: Anterior close-up view showing widened symphysis. C: Anterior close-up view showing reduced symphysis.
A: AP view with clamp in place. B: Anterior close-up view showing widened symphysis. C: Anterior close-up view showing reduced symphysis.
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Figure 46-51
Bony pelvic model showing Farabeuf clamp anteriorly.
 
A: Widened symphysis. B: Reduced symphysis.
A: Widened symphysis. B: Reduced symphysis.
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Figure 46-51
Bony pelvic model showing Farabeuf clamp anteriorly.
A: Widened symphysis. B: Reduced symphysis.
A: Widened symphysis. B: Reduced symphysis.
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Pointed reduction clamps (Weber) have been used with points of contact described within the obturator foramen or into the lateral aspect of the body. Care must be taken with all of these reduction maneuvers in osteopenic bone. In good quality bone, a pilot hole can be drilled on each pubic body anteriorly into which the tines of either a modified Weber clamp or a craniomaxillofacial (CMF) clamp (tines are almost parallel) can be placed (Fig. 46-52A–C). An additional option is the use of Schanz pins from a previously placed fixator, or new pins that can be placed temporarily in the supra-acetabular region as described previously. These can be used to manipulate the injured side. Throughout reduction maneuvers, the c-arm is used to obtain satisfactory AP, inlet, and outlet images to ensure that anatomic reduction has been achieved. Regardless of the technique used, proper placement of the screws (for the Jungbluth or Farabeuf clamps) or the reduction forceps will allow for drilling for screw placement and plate application superiorly (Fig. 46-53). When there is considerable damage to the cartilage within the symphysis or loose fragments, excision of the cartilage can be performed prior to reduction and fixation. 
Figure 46-52
 
A–C: Bony pelvic model showing CMF clamp anteriorly A: Close-up of clamps. B: Widened symphysis. C: Reduced symphysis.
A–C: Bony pelvic model showing CMF clamp anteriorly A: Close-up of clamps. B: Widened symphysis. C: Reduced symphysis.
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Figure 46-52
A–C: Bony pelvic model showing CMF clamp anteriorly A: Close-up of clamps. B: Widened symphysis. C: Reduced symphysis.
A–C: Bony pelvic model showing CMF clamp anteriorly A: Close-up of clamps. B: Widened symphysis. C: Reduced symphysis.
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Figure 46-53
Bony pelvic model showing ability to drill medially to previously placed screws for use of Jungbluth or Farabeuf clamps.
Rockwood-ch046-image053.png
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Once reduction has been obtained and confirmed, plate fixation can be applied. Various plate configurations have been described in the literature.167,288,307,368 Debate has centered around the need to maintain some “physiologic” motion at the symphysis, and thus two hole plates have been advocated.368 The use of two hole plates has shown a higher rate of failure and pelvic malunion, leading pelvic surgeons to use alternative plates that allow for at least two points of fixation on either side288 or dual plating which allows for multiplanar fixation.306,307,316 Our preference is for use of a small fragment symphyseal specific plate, which allows for either two or three points of fixation on each side of the symphysis (Fig. 46-54A–D). Alternatively, a 3.5- or 4.5-mm pelvic reconstruction plate (generally a 4 to 8 hole plate, depending on the anatomy and size) can be used and contoured to fit over the symphysis. This also will allow the same number of fixation points to occur. If the bone is osteoporotic, locked screws may be used in many of the plates available today, although the advantages to the use of such locked plates have been questioned.118,205 
Figure 46-54
Photographs of symphyseal specific designed plates.
 
A: Top with oblong holes centrally and locking holes peripherally; bottom plate with all locking holes. B–D: Representation of plate applications superiorly with CMF clamp holding reduction (B, old style four-hole plate; C, oblong symphyseal plate; D, locking symphyseal plate).
A: Top with oblong holes centrally and locking holes peripherally; bottom plate with all locking holes. B–D: Representation of plate applications superiorly with CMF clamp holding reduction (B, old style four-hole plate; C, oblong symphyseal plate; D, locking symphyseal plate).
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Figure 46-54
Photographs of symphyseal specific designed plates.
A: Top with oblong holes centrally and locking holes peripherally; bottom plate with all locking holes. B–D: Representation of plate applications superiorly with CMF clamp holding reduction (B, old style four-hole plate; C, oblong symphyseal plate; D, locking symphyseal plate).
A: Top with oblong holes centrally and locking holes peripherally; bottom plate with all locking holes. B–D: Representation of plate applications superiorly with CMF clamp holding reduction (B, old style four-hole plate; C, oblong symphyseal plate; D, locking symphyseal plate).
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During drilling, a malleable retractor is placed to protect the bladder. We prefer to use a malleable retractor that is somewhat radiolucent to help with imaging during plate application. If residual reduction is required, the plate can be used to obtain some compression by following AO principles of eccentric drilling. If this is done, the two screws closest to the midline should be placed first. Care must be taken to ensure that the rest of the plates, on each end, are still on the bone. Proper trajectory for drilling can be determined by finger palpation on the inside of the pubis. Even if locked plates are used, albeit not routinely needed, it is recommended that the initial two screws be nonlocking such that the plate can be placed onto the bone. Use of such screws will also aid in reduction in the sagittal plane, and will allow for any other adjustments needed before finalizing the fixation. These minor adjustments can be made with pointed reduction forceps placed in an oblique fashion, one tine anterior on one body and the other posterior on the contralateral body. The determination of which tine goes on what side is based on the side needs to be brought forward. The side posterior should have the tine placed posteriorly, and thus with a rotational motion toward the anterior side, the posterior body can be brought forward. Again, adequate and frequent intraoperative imaging should be used to ensure maintenance of the reduction throughout plate application. A second nonlocking screw can aid in this and use of a ball spike to push the plate down to realign with the opposite side. Use of the longest screw possible while obtaining bicortical purchase should be attempted. Screws should exit the inferior aspect of each body. Care should be taken to avoid posterior penetration as the screw ends can irritate, perforate, or erode into the bladder over time. Final screw placement is then performed followed by final intraoperative imaging. 
If dual plating is chosen or needed in cases when the initial plate exhibits poor fixation, the second plate is placed anteriorly. A four- to six-hole pelvic reconstruction plate is generally used. Care must be taken to place the screws around the screws from the other plate, which can often be challenging. An option to use only two screws in the anterior plate, directed almost colinearly with the superior ramus, has been described instead of the usual anterior–posterior direction traditionally used.316 
Closure is then performed of the surgical exposure after the retropubic space is adequately irrigated. We routinely drain the space of Retzius with a small diameter round Blake drain (fluted). The drain should be brought out away from the incision. Nonabsorbable suture in an interrupted figure-of-eight fashion is used to close the rectus fascia and muscle as one single layer. Subcutaneous closure is performed with absorbable suture and skin is closed with staples, although in some female patients who have expressed cosmesis concerns, a subcuticular closure with Dermabond tape has been used. 
Postoperative Care.
Postoperatively, toe touch weightbearing restrictions are placed on the side of the posterior ring injury regardless of the completeness of the injury. This is done for 12 weeks. The drain is removed generally at 48 hours and prophylactic antibiotics continued during this time and discontinued at time of drain removal. DVT prophylaxis is used for at least 6 weeks and is ultimately dependent on the patient’s associated injuries and mobility status. Staples or sutures are removed at 2 weeks. 
Plate removal has been discussed because the long-term effects have not been well understood, and there has been no consensus as to the need for hardware removal.257 Suprapubic pain, impotence, and dyspareunia were unrelated to implant status in a retrospective review of patients with symphyseal plating.105 In addition, implant failure was asymptomatic in this series, which also questioned the need for plate removal. The need for removal in women of childbearing age has not been determined; several authors have reported that vaginal delivery has been successful even with retained hardware.35,105,357 In general, we do not routinely remove symphyseal hardware in these female patients who may have required internal fixation. Discussion with these patients is recommended about the potential need for a cesarean section based on the size of the baby, but the decision should be left to the obstetrician and the patient. 
Potential Pitfalls and Preventive Measures.
Poor reduction, failure or loosening of reduction, or inability to obtain reduction can occur. Poor reduction is usually a failure to use adequate intraoperative imaging or improper plate application, which can sometimes cause displacement when screws are being placed, or releasing “clamps” prior to two points of fixation being placed on each side of the symphysis when the reduction was being held. We do not recommend the use of two-hole plates, since rotational instability cannot be controlled and because of the high failure rate. If fixation with a single plate seems to be insufficient, supplementing with an anterior plate can be helpful. Alternatively, if fixation is poor, an external fixator can be applied. 
Failure of the hardware is often results from weightbearing or underappreciation of the severity of posterior ring injury resulting in excess stress of the anterior fixation and subsequent failure. If significant posterior instability is detected, posterior fixation should be considered. 
Inability to obtain the reduction can occur for many reasons including failure to appreciate the associated ring injuries such as a concomitant rami fracture, posterior displacement or rotational component, concomitant acetabular fracture, or delayed presentation. 
Excessive bleeding can occur if the corona mortis is violated with extensive lateral dissection. If this occurs, one must work quickly to gain control and cauterize or if possible ligate the vessel. In extreme cases or when bleeding cannot be controlled adequately, packing should be undertaken with immediate skin closure and the angiography suite being alerted for embolization. 
Bladder injury can occur with improper “drilling” trajectory. A malleable retractor should always be used to protect the bladder. A Foley catheter should always be used to decompress the bladder. Formation of blood-tinged urine during the procedure can alert one to injury. In such cases, intraoperative urology consultation should occur. 
Treatment-Specific Outcomes.
In patients with rotationally unstable injuries but vertically stable injuries, anterior fixation alone has been shown to be sufficient.244 When posterior fixation is needed in such injury patterns, still remains to be answered. Many outcome studies on pelvic ring fractures are reported, but do not necessarily one individual injury pattern or method of treatment. Because the patient populations are heterogeneous in terms of injuries and treatment, it is difficult to evaluate any single method of treatment alone. 
Kellam did show that when an adequate reduction of <2 cm of the symphysis pubis was obtained in rotationally unstable injuries, 100% of the patients returned to normal function.150 However, only 31% of patients had normal function when they had associated posterior pathology. Similar findings show the importance of an anatomic reduction of the anterior injury in these APC II patterns to favorable outcomes.346 
In terms of plate fixation of the symphysis, hardware failure is a common reported occurrence but it does not seem to correlate with functional outcome.105,254,257,288 Despite successful radiologic outcomes and anatomic restoration of the pelvic ring, those patients that require both anterior and posterior fixation still report functional limitations as a continued problem.21,150,248,254 In a study with 1 year of follow-up, the mean SF-36 physical score was approximately 20% lower than that in the normal population and patients reported their physical function at 69% of normal.254 A recently described alternative to plate fixation, percutaneous screw fixation across the symphysis, did show some promise for improved results.44 In this prospective study of 90 patients, equally dispersed and treated with either method, the authors reported significantly improved functional Majeed scores and less blood loss. Reduction, implant failure, malunion, revision rates, and male impotence were all found to be equal in both groups. Although this is one relatively small series, further evaluation of this percutaneous method seems warranted. 

Surgical Treatment of Rami Fractures

At times, surgical stabilization of rami fractures may be warranted. This is usually in the case of the rami fracture(s) associated with VS injuries, where there is considerable soft tissue damage around the anterior ring. In addition, in any posterior ring injury where there is considerable instability and associated soft tissue damage, it may be desirable to augment the posterior fixation with anterior fixation. Fortunately this is rare, and many rami fractures can be treated nonoperatively, since these are not ligamentous disruptions as in the case of symphyseal diastasis. The soft tissue structures can aid in the successful healing of these fractures. The periosteum provides a biologic environment, whereas the inguinal ligament provides a mechanical environment by stabilizing the fracture when the location of the fracture is lateral to its insertion. If medial, the fracture tends to act similar to a symphyseal disruption, with widening, and thus may require formal surgical management. 
Options for operative stabilization include ORIF utilizing pelvic reconstruction plates, external fixation, and percutaneous stabilization with screw fixation in either an antegrade or retrograde fashion.275,322,323 Stabilization with a retrograde screw has been biomechanically evaluated and found to be comparable to that of plate fixation.302 Unilateral injuries can often be treated with any of these methods if there is significant displacement or in an effort to augment posterior fixation. With bilateral injuries, ORIF can require extensive dissection and may be counterproductive; an external fixator can stabilize the anterior ring injury allowing fracture healing to occur or percutaneous techniques can be utilized. 
A prerequisite for percutaneous techniques is obtaining a reduction before screw placement. If the reduction can be performed closed or carefully in a minimally invasive manner with a bone hook as described,322 then a percutaneous technique is probably preferred. Starr et al.322 classified rami fractures (Nakatani classification) into three types by looking at their percutaneous results in an attempt to determine what would potentially predict fixation failure. Overall there was a 15% loss of reduction, which was more common in elderly patients, female patients, and patients who had screws placed retrograde. Anterior loss of reduction was always accompanied by loss of posterior reduction. Most cases of loss of reduction involved fractures medial to the lateral border of the obturator foramen (Nakatani Zone II injuries more so than Nakatani Zone I). In addition, retrograde screws failed more often. 
If a percutaneous method is chosen, either antegrade or retrograde methods may be used.275,322,323 Multiple factors should be considered when choosing the technique, including the location of the fracture,322 the patient’s habitus, associated soft tissue injuries, bony anatomy and space available for screw placement, and surgeon’s experience with both techniques. Antegrade screws may be better utilized when the fracture is lateral, near the pubic root, or in the middle of the ramus, or the patient is morbidly obese (as long as fracture pattern is amenable). Retrograde screws are useful for those medially based fractures. Regardless of the direction used, intraoperative fluoroscopy and a technician well versed in obtaining appropriate images are paramount for a successful and stressfree surgery. Placement of a guide wire and ultimately the screw must be accomplished utilizing the obturator oblique view (OOV) and iliac inlet or inlet view (IV), so as not to penetrate the cortex or exit out the fracture site. The external iliac vascular structures are at risk superiorly (OOV), acetabulum inferiorly (OOV), the bladder inwardly (IV), and the corona mortis inwardly (IV) (Fig. 46-55). 
Figure 46-55
The corona mortis is demonstrated on the inside of the superior pubic rami about 6 cm from the symphysis.
 
It represents the anastomosis of the obturator artery and the external iliac artery.
 
(Adapted from: Wiesel S. Operative techniques in orthopaedic surgery. Philadelphia, PA: Lippincott Williams & Wilkins; 2010.)
It represents the anastomosis of the obturator artery and the external iliac artery.
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Figure 46-55
The corona mortis is demonstrated on the inside of the superior pubic rami about 6 cm from the symphysis.
It represents the anastomosis of the obturator artery and the external iliac artery.
(Adapted from: Wiesel S. Operative techniques in orthopaedic surgery. Philadelphia, PA: Lippincott Williams & Wilkins; 2010.)
It represents the anastomosis of the obturator artery and the external iliac artery.
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Surgical Techniques

ORIF of Ramus Fracture.
ORIF of a ramus fracture can be performed through the Pfannenstiel incision, but often extension of this into a Stoppa or full ilioinguinal may be required. The usual precautions as indicated previously should be undertaken. Because of the extensive exposure required, many surgeons prefer percutaneous techniques to minimize the need for such exposure. In any event, if ORIF is undertaken, fixation often needs to occur lateral to the pubic root, which requires the screws to be placed in the supra-acetabular bone. Care must be taken to avoid intra-articular screw penetration into the acetabulum. The OOV can be useful during this procedure (Fig. 46-56A–C). The plate can be applied laterally to begin with and the then used as a reduction tool. A clamp can be placed through the plate and the other side onto the medial fragment, bringing the plate to the bone. Plate application must be collinear with the bone and requires some contouring to ensure that the plate will be on the bone once reduction is achieved. Pelvic reconstruction plates are best for this purpose. Some have been precontoured to aid in this procedure. Final fixation is accomplished with screws through the medial aspect of the plate into the medial fracture fragment. If the symphysis is also disrupted, a longer plate can be utilized and extended to cross over the midline and onto the opposite ramus. Attention to detail is required to ensure that the plate fits appropriately on the bone. Closure is done in the same fashion, and a round Blake drain is used. 
Figure 46-56
Patient with unstable pelvic ring injury (widening through right-sided sacral fracture and superior ramus anteriorly).
 
A: AP view showing right superior ramus fracture and bilateral sacral injuries. B: Intraoperative fluoro obturator oblique view (OOV) to insure screws in supra-acetabular bone above the joint. C: Postoperative AP view showing reduction of anterior ring and stabilization of right-sided sacral fracture.
A: AP view showing right superior ramus fracture and bilateral sacral injuries. B: Intraoperative fluoro obturator oblique view (OOV) to insure screws in supra-acetabular bone above the joint. C: Postoperative AP view showing reduction of anterior ring and stabilization of right-sided sacral fracture.
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Figure 46-56
Patient with unstable pelvic ring injury (widening through right-sided sacral fracture and superior ramus anteriorly).
A: AP view showing right superior ramus fracture and bilateral sacral injuries. B: Intraoperative fluoro obturator oblique view (OOV) to insure screws in supra-acetabular bone above the joint. C: Postoperative AP view showing reduction of anterior ring and stabilization of right-sided sacral fracture.
A: AP view showing right superior ramus fracture and bilateral sacral injuries. B: Intraoperative fluoro obturator oblique view (OOV) to insure screws in supra-acetabular bone above the joint. C: Postoperative AP view showing reduction of anterior ring and stabilization of right-sided sacral fracture.
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Antegrade Percutaneous Screw Fixation.
Antegrade screw insertion for superior ramus fractures (Fig. 46-57A–F) is generally performed with the patient supine, although it is possible with prone placement. The entire pelvic area is draped and prepped, similar to that for ORIF, in the event that an open procedure is required. Intraoperative fluoroscopy is used throughout the procedure, shifting between OOVs and inlet views. The guide pin for a 6.5/7.3 mm screw is used and placed percutaneously above the acetabulum in line with the level of the greater trochanter. The starting point has been described as being the midpoint on a line between the tip of the greater trochanter and a spot about 4 cm posterior to the ASIS.323 In addition, the author uses a line drawn on the skin, which marks the trajectory of the screw by using the OOV to determine the starting point. The pin should be directed slightly distal in line with the ramus and slightly anterior. 
Figure 46-57
 
A–C: 3D AP, inlet, and outlet views of patient with pelvic ring injury encompassing bilateral superior/inferior rami fractures (straddle injury) and right-sided complete sacral fracture. D–F: Postoperative AP, inlet, and outlet views showing stabilization of right side with antegrade percutaneous screw and left side with retrograde percutaneous screw.
A–C: 3D AP, inlet, and outlet views of patient with pelvic ring injury encompassing bilateral superior/inferior rami fractures (straddle injury) and right-sided complete sacral fracture. D–F: Postoperative AP, inlet, and outlet views showing stabilization of right side with antegrade percutaneous screw and left side with retrograde percutaneous screw.
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A–C: 3D AP, inlet, and outlet views of patient with pelvic ring injury encompassing bilateral superior/inferior rami fractures (straddle injury) and right-sided complete sacral fracture. D–F: Postoperative AP, inlet, and outlet views showing stabilization of right side with antegrade percutaneous screw and left side with retrograde percutaneous screw.
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Figure 46-57
A–C: 3D AP, inlet, and outlet views of patient with pelvic ring injury encompassing bilateral superior/inferior rami fractures (straddle injury) and right-sided complete sacral fracture. D–F: Postoperative AP, inlet, and outlet views showing stabilization of right side with antegrade percutaneous screw and left side with retrograde percutaneous screw.
A–C: 3D AP, inlet, and outlet views of patient with pelvic ring injury encompassing bilateral superior/inferior rami fractures (straddle injury) and right-sided complete sacral fracture. D–F: Postoperative AP, inlet, and outlet views showing stabilization of right side with antegrade percutaneous screw and left side with retrograde percutaneous screw.
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A–C: 3D AP, inlet, and outlet views of patient with pelvic ring injury encompassing bilateral superior/inferior rami fractures (straddle injury) and right-sided complete sacral fracture. D–F: Postoperative AP, inlet, and outlet views showing stabilization of right side with antegrade percutaneous screw and left side with retrograde percutaneous screw.
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Once guide pin placed and the placement proximal to the acetabulum confirmed, the inlet view is obtained to ensure that the pin is in line with the superior ramus. If not, adjustments are made accordingly. Once the trajectory of the pin is confirmed on both OOV and inlet, the pin is advanced down the column and across the fracture (Fig. 46-58A,B). It is important to stay within the confines of the bone so as not to cause injury to the bladder or corona mortis. Keep in mind that reduction of the ramus fracture must be performed prior to placement of the guide wire. If this cannot be done closed, a percutaneous method by making a stab incision through the rectus or linea alba and utilizing a carefully placed bone hook or joker elevator can reduce the fracture.322 
Figure 46-58
Intraoperative obturator outlet view (A) and inlet view (B) confirming placement of guide wire within the bone on right.
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In some cases, as the guide wire is advanced it may distract the fracture site. As long as the distraction is in the plane of eventual compression this can be accepted, but an appropriate size of screw must be selected. The skin is then incised at the insertion point of the pin. The length is measured and an appropriate-length partially threaded screw is placed. A washer can be used if there is concern about osteopenic bone, since the head of the screw can penetrate the lateral cortex. Compression of the fracture should occur with final seating. Stabilization is now complete (Fig. 46-59A, B). The small incision can be closed after irrigation, with a single subcuticular stitch and staples or SteriStrips. Sterile dressing is applied. 
Figure 46-59
Intraoperative obturator outlet view (A) and inlet view (B) confirming screw placement and stabilization of fracture on right.
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Retrograde Percutaneous Screw Fixation.
Patient positioning and preparation of the surgical field for retrograde screw insertion is the same as that for antegrade fixation (see Fig. 46-57A–F); however, attention must be placed on ensuring adequate access to the symphyseal region, more so than in the antegrade technique. A small incision is generally made aligned more over the contralateral pubic tubercle adjacent to the base of the penis or mons pubis. Blunt dissection is then directed toward the injured pubic tubercle. Soft tissue sleeves should be used for drills, unless cannulated screws are used over guide wires. The use of cannulated screws in retrograde fashion is dependent on the size of screw desired. We generally use 3.5 or 4.5 solid pelvic screws placed in AO lag screw fashion; however, 6.5/7.3 mm cannulated screw systems can also be used. Reduction of the fracture must be accomplished through closed means or by utilizing percutaneous methods mentioned earlier. 
The sliding hole is created first with either a 3.5 or 4.5 mm oscillating drill bit followed by the 2.5 or 3.2 mm oscillating drill bit, and directed retrograde through the superior ramus, across the fracture and above the acetabulum if so desired. If a cannulated screw system is used, the guide wire can be advanced across the fracture site in a retrograde fashion. If the rami fracture is sufficiently medial, the screw can be stopped short just medial to the acetabulum. We prefer long screws if the anatomy allows. Biplanar obturator-outlet and inlet imaging must be performed throughout drilling to ensure that proper trajectory is maintained and the drill bit remains in the confines of the ramus (Fig. 46-60A–D). A long depth gauge or the subtraction method utilizing a second drill can be performed, if a calibrated drill bit/soft tissue sleeve system is not available, to determine screw length or the guide wire measured. The appropriate screw is then placed. A washer may be used if the bone is felt to be osteopenic, so as not penetrate the cortex with the head of the screw, or if more compression is desired. Stabilization is now complete (Fig. 46-61A, B). The wound is then irrigated and subsequently closed with subcuticular sutures followed by staples or SteriStrips. 
Figure 46-60
Intraoperative inlet view (A, D) and obturator outlet view (B, C) confirming placement of guide wire within the bone on left.
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The screw enters the pubic tubercle just distal to the fracture site.
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Figure 46-61
Intraoperative obturator outlet view (A) and inlet view (B) confirming screw placement and stabilization of fracture on left.
The screw enters the pubic tubercle just distal to the fracture site.
The screw enters the pubic tubercle just distal to the fracture site.
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Postoperative Care.
Postoperatively, toe touch weightbearing restrictions are placed on the side of the posterior ring injury regardless of the completeness of the injury; this is done for 12 weeks. The drain is removed generally at 48 hours, and prophylactic antibiotics are continued during this time and discontinued at time of drain removal. DVT prophylaxis is used for at least 6 weeks and is ultimately dependent on the patient’s associated injuries and mobility status. Staples or sutures are removed at 2 weeks. 
Potential Pitfalls and Preventative Measures.
When plating rami fractures, care must be taken to ensure that the corona mortis is identified and ligated, otherwise excessive and rapid bleeding can occur. Screw placement above the acetabulum should be confirmed with fluoroscopy. If screw purchase is insufficient, plating can be extended across the symphysis if need be, or an external fixator can be applied to augment fixation. This may be problematic if the supra-acetabular region has screws. 
Inadvertent perforation of adjacent structures is the biggest risk in percutaneous placement and can be avoided by proper and frequent imaging throughout the procedure to ensure that the proper trajectory is maintained. In addition, screws can be malpositioned for the same lack of attention to proper imaging while placing the screws, or inadequate reduction. Screw length should be measured appropriately so as to minimize perforation through the pubic tubercle medially (antegrade screws) such that the screw abuts against the contralateral tubercle and causes pain. Furthermore, screws can lose fixation and back out, which most often is related to the length of the screw, namely retrograde short screws placed just to the acetabulum. The screw can be replaced with a much longer one to improve fixation. 
Patients should always have retrograde urethrogram or a cystogram to evaluate the bladder and associated structures. Perforation of the bladder can occur due its proximity to the fractured rami. Rare entrapment of the bladder within the fracture site has also been reported.202 
Treatment-Specific Outcomes.
The technique for rami fractures has been shown to be effective, with a 15% failure rate in the largest series.322 The majority of these were retrograde for Nakatani Zone II fractures. The antegrade failure rate was only 2.5% in the same series. In addition, caution was exercised for the use of retrograde screws in lateral compression injuries. No large series in the plating of rami fractures has been published to date. Simonian et al.302 did show that anterior pelvic stability was similar for both the retrograde screw and plate techniques. 

Surgical Procedures of the Posterior Pelvic Ring

Positioning for Posterior Approach for Posterior Ring Injuries: SI Joint Dislocations, Sacral Fractures, and Crescent Fractures.
Posterior procedures require prone positioning, which can sometimes be problematic for the multiply injured patient with concomitant abdominal or thoracic injuries. In patients who can tolerate a prone position and who require a posterior approach, a fully radiolucent table is used. If traction is needed, we prefer to use a sterile distal femoral traction pin and bow, which is attached to weights and hung over on the end of the bed. Many different options exist, and surgeons have their preferences. Beds specifically designed to allow for boot traction can also be used. Others have described methods to fix the contralateral pelvis to the table, allowing stabilization such that aggressive traction can be applied to the operative side.172,191 This technique has been useful for severely injured pelvic rings with significant vertical displacement. Regardless of the preferred method, the ability to apply intraoperative traction on the hemipelvis can be useful and arrangements made in the event it is needed. 
When placing patients in a prone position, it is important to properly pad the patient. We use either longitudinal “jelly” rolls or rolled-up blankets along the torso, which helps to support the thoracic cavity to allow for adequate ventilation. On the extremity that is not prepped in, “jelly” rolls are used under the knee with pillows under the foot. The opposite, injured side is left free or traction is applied depending on the situation. Whatever type of chest support is used, it must be set out of the way of potential c-arm imaging as these can cause shadows on imaging. In addition, supports must stop short of the pelvis such that the ASIS is not resting on the support, as this can lead to posterior translation of the hemipelvis, and be counterproductive for the reduction to be obtained. Extension of the affected side can also aid in reduction and eliminate the flexion deformity that often exists with many SI disruptions. 
Once the patient is appropriately positioned, we bring the c-arm in for a “test run” to ensure that images can be obtained and that there are no obstacles to proper visualization of all structures. This includes gas shadows in the gastrointestinal tract from an ileus, which many trauma patients develop. In an effort to reduce this, often a nasogastric tube or oral gastric tube at low wall suction can help. In addition, this test run allows the technician to become familiar with the images required for the surgical procedure, and the c-arm can be marked for the proper angles needed to reproduce the images, which is especially useful if the radiology technician changes during the procedure, which is too often the norm. 
In addition, the fluoroscopy machine can gauge the reduction if longitudinal traction is being applied in the cases of a vertically translated SI joint dislocation or sacral fracture. This will suggest whether a formal reduction is required for the latter injury. Critical evaluation of the images to ensure that anatomic reduction has been achieved should be undertaken. Reilly et al.260 has shown that fracture stability is improved when as close to an anatomic reduction has been obtained. Proper reduction of the sacral fracture allowed for safe placement of an iliosacral screw by increasing the diameter of the safe corridor for the implant. Once confirmation of adequate and appropriate images (AP, inlet, outlet) is complete, the patient can be draped in anticipation of prepping. 
The entire flank on the affected side, extending down around the groin to include the entire ipsilateral extremity should be included. In addition, the drape should be extended to the opposite side and down the flank just above the contralateral buttock to the side of the table. We include access to both SI joints, but exclude the midline cleft and contralateral buttock in the field. The area can then be prepped and surgically draped. We apply a layer of Ioban to the surgical field. 
Sacral deformities and defects should be evaluated prior to any open or percutaneous procedures. The presence of sacral dysmorphism has been shown to be problematic for iliosacral screw placement and must be recognized.277 Sacral dysmorphism occurs usually in the form of sacralization of the fifth lumbar body but can also occur as lumbarization of the first sacral body (see Fig. 46-32A–C). When these variations in anatomy occur, it is important to preoperatively plan for screw placement, as placement of traditional transiliac screws, if needed, in the first sacral body cannot be accomplished.200 In cases of open reduction and internal fixation of sacral fractures, careful evaluation of the CT scan for nerve root impingement and the appropriate levels should be noted (Fig. 46-62A–D). The presence of an occult spina bifida should also be identified, so that iatrogenic injury to the nerves within the sacral spinal canal is prevented from routine midline placement of a clamp for reduction purposes or from deep midline dissection.289 
Figure 46-62
CT scan images showing intraforaminal fragments (arrows).
 
A: Coronal S1. B: Coronal S2. C: Sagittal S1. D: Sagittal S2.
A: Coronal S1. B: Coronal S2. C: Sagittal S1. D: Sagittal S2.
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Figure 46-62
CT scan images showing intraforaminal fragments (arrows).
A: Coronal S1. B: Coronal S2. C: Sagittal S1. D: Sagittal S2.
A: Coronal S1. B: Coronal S2. C: Sagittal S1. D: Sagittal S2.
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Surgical Approaches for Fixation of the Posterior Pelvic Ring.
Posterior Approach for Posterior Ring Injuries
Sacroiliac Joint Dislocations, Posterior Approach
With the patient positioned prone and draped as described previously, a paramedian incision centered over the involved SI joint in a vertical fashion is drawn out (Fig. 46-63). The incision should be placed just medial to the posterior superior iliac spine so as not to be directly over a bony prominence. Prior to incision, 1% lidocaine with epinephrine is injected into the length of proposed skin incision to help decrease blood loss. The skin is incised and the subcutaneous tissues are dissected down to the fascia. 
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Figure 46-63
Posterior approach to SI Joint.
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The soft tissues that cover the posterior aspect of the SI joint may be disrupted to varying degrees. This may provide direct visualization into the SI joint. However, if the tissues are intact, further dissection is required. The posterior soft tissue complex overlying the SI joint comprises the lumbodorsal fascia (LDF), the transverse fibers of the gluteus maximus (TGM), the paraspinal erector spinae muscles (ES), the iliolumbar ligament (ILL), and the posterior SI ligaments (PSILs). 
Deeper dissection is required to gain better visualization of the SI joint. To visualize the inferior aspect of the SI joint, the TGM needs to be mobilized. The fibers are removed from the sacral spinous processes and the LDF. Caution must be exercised avoid transection of the ES, which crosses at 90 degrees underneath. These muscles are reflected laterally and inferiorly, thereby exposing the joint. If palpation is needed to assess the reduction of the anterosuperior aspect of the SI joint, the LDF will need to be released from the posterior iliac crest. This allows for further dissection up over the superior aspect of the SI joint and sacral ala. This should allow for adequate exposure to reduce the SI joint. If dissection around the notch is required for clamp placement, care should be taken to avoid injury to the superior gluteal neurovascular bundle. Any dissection along the crest should avoid damage to the cluneal nerves, which could result in neuroma formation. 
Upon exposure, a significant amount of blood clot and hematoma from the joint is often encountered. This should be evacuated and the joint irrigated. Attention should be paid to the superior gluteal vessels and the internal iliac vascular system, since either or both of these may have been the source for the bleeding. Arterial bleeding may restart once the clot is removed, as it may have been controlled by tamponade and/or vasospasm. Any free articular cartilage fragments should be extracted. At this point, reduction of the SI joint can be accomplished using a multitude of reduction maneuvers. Reduction and placement of clamps can be easier from a posterior approach and thus is preferred by some.106 Fixation is usually accomplished with iliosacral screw placement, although other options such as plating can be performed.162 
Sacral Fractures: Posterior Approach
As opposed to SI joint dislocations, which may be reduced via anterior or posterior approaches, all sacral fractures that require formal open reduction must be done from a posterior approach. It is extremely difficult if not possible to access the anterior aspect of the sacrum from an anterior approach due to the extreme risk to the lumbosacral nerve roots and iliac vessels. This approach is not recommended. 
The positioning and setup are identical to those for SI dislocations. One of two incisions can be performed depending on the location and type of fracture, need for sacral root decompression, and the type of fixation planned: either the paramedian approach for intertransverse spine fusions as described by Wiltse370 or a midline incision. Reduction is most easily performed through a midline incision, but care must be taken preoperatively to detect any occult spina bifida of the sacrum. This can be present in up to 15% of patients.289 
The paraspinal muscles are elevated subperiosteally from the spinous processes, over the sacrum, to the posterior inferior iliac spine (PIIS) and PSIS of the ilium. The fracture line will be encountered during the elevation, and care must be taken to avoid falling into the spinal canal through any defects or laminar fractures. It is important to maintain the integrity of the posterior SI ligaments, which are intact in sacral fractures. 
Alternatively, a paramedian incision can be used. However, the deep dissection is altered from the exposure used to access the posterior SI joint. To expose the sacral fracture site, the distal intermuscular plane between the multifidus and longissimus paraspinal muscles just proximal to the PSIS is developed. The paraspinal muscles are then elevated away from the crest and off the posterior aspect of the sacrum in a reverse fashion from the midline approach. Caution must be exercised again when the fracture line is encountered. Because the dissection is performed from lateral to medial, starting at the PSIS, and exposes the L4-L5 facet joint via proximal extension if needed, this approach is especially helpful for placement of spinal pelvic fixation constructs (Fig. 46-64). 
Figure 46-64
 
A. Skin incision for posterior approach to sacrum and sacroiliac joint. B. Diagram of fascial fibers and muscular layers for posterior approach to sacrum and sacroiliac joint. C. Posterior exposure for sacral fracture reduction.
 
(From Wiesel S, Operative Techniques in Orthopaedic Surgery. Philadelphia: Lippincott Williams & Wilkins 2010 with permission)
A. Skin incision for posterior approach to sacrum and sacroiliac joint. B. Diagram of fascial fibers and muscular layers for posterior approach to sacrum and sacroiliac joint. C. Posterior exposure for sacral fracture reduction.
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Figure 46-64
A. Skin incision for posterior approach to sacrum and sacroiliac joint. B. Diagram of fascial fibers and muscular layers for posterior approach to sacrum and sacroiliac joint. C. Posterior exposure for sacral fracture reduction.
(From Wiesel S, Operative Techniques in Orthopaedic Surgery. Philadelphia: Lippincott Williams & Wilkins 2010 with permission)
A. Skin incision for posterior approach to sacrum and sacroiliac joint. B. Diagram of fascial fibers and muscular layers for posterior approach to sacrum and sacroiliac joint. C. Posterior exposure for sacral fracture reduction.
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Once the fracture has been exposed, decompression of sacral nerve roots, usually in cases of transforaminal fractures, can be performed and reduction of the fracture achieved. Direct visualization of the fragments causing nerve root irritation can be accomplished through the fracture site. To gain better access, a lamina spreader can be carefully placed into the fracture site. Irrigation should help clean out the clot and loose fragments, thereby allowing visualization of the medial aspect of the sacrum. The nerve root can be visualized as well as the offending fragment. If the nerve root is still not well visualized, part of the sacral lamina can be removed with pituitary rongeurs. Reduction can then be performed safely followed by fixation. The choice of fixation depends on the fracture configuration and whether the injury is unilateral or bilateral. Options include unilateral or bilateral iliosacral screw fixation, transiliac screw fixation, plating, and sacral bars. For special cases of lumbopelvic disassociation, spinal pelvic constructs are required. 
Crescent and Iliac Wing Fractures: Posterior Approach
Iliac wing fractures that are more medial and posterior and crescent fracture dislocations, which involve a considerable portion of the SI joint, can be managed from a posterior approach, using the same incision and surgical approach that is used for SI dislocations. A curvilinear incision along the crest posteriorly can be utilized in those cases where the fracture line exits the crest more laterally and anteriorly (see Fig. 46-63). 
The deep dissection involves elevating the gluteal muscles away from the external iliac fossa, from the PSIS and crest down to the greater sciatic notch. Although the surgeon needs to be cautious regarding the TGM as mentioned previously, the TGM is more likely to already be damaged from the traumatic injury. The entire muscle is carefully reflected laterally and distally allowing exposure of the entire outer table of the ilium (Fig. 46-65). The full extent of the fracture should be visualized to ensure that an anatomic reduction has been obtained and no residual displacement at the notch still exists. Both iliac wing fractures and crescent fractures can be reduced and fixation applied. 
Figure 46-65
Deep exposure of posterior approach showing elevation of gluteal musculature off lateral aspect of ilium and exposure of iliac wing fracture.
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Positioning for Anterior Approach for Posterior Ring Injuries: SI Joint Dislocations, Iliac Wing Fractures, and Crescent Fractures.
For open reduction procedures of the SI joint, iliac wing fractures, or small crescent fractures from an anterior approach, the patient is usually placed in the supine position. Depending on the body habitus, a bump can be placed under the affected side in an effort to allow for more posterior access for the incision. In thin individuals, this is usually not needed. If a bump is used, fluoroscopic imaging must take the “tilt” into consideration to obtain proper views. 
Just as in the case for any SI joint injury, one must be ready to apply longitudinal traction if needed intraoperatively, and thus the entire affected side extremity is usually draped in. The entire anterior area of the pelvis (see anterior approaches for anterior ring fixation) to include past the midline is draped in. The c-arm should be brought in again to assess adequacy of imaging as well as reduction if longitudinal traction is applied, or if reduction is performed with use of other closed methods such as a sheet wrapped around the pelvis at the level of the greater trochanters or taping of the lower extremities (precludes extremity prepping).94 
Anterior Approach for Posterior Ring Injuries.
The anterior approach for the treatment of posterior ring injuries (Fig. 46-66A–G) can be performed to treat SI joint dislocations, anterior iliac wing fractures, certain iliac wing fracture-dislocations (crescent fractures), and in the occasional situations when the L5 nerve root is found invaginated into the sacral fracture. The approach is performed with the patient in the supine position. The incision is made starting 1 to 2 cm posterior to the ASIS, so as to prevent injury to the lateral femoral cutaneous nerve, and heading back along the iliac crest (Fig. 46-66A). This is essentially the proximal portion of the Smith-Peterson (iliofemoral) approach, or the lateral window of the ilioinguinal approach. Regardless of the name, the approach allows access into the iliac fossa. The skin is incised down through the subcutaneous tissue until the external oblique muscle fibers (EOM), overlying the crest, are encountered (Fig. 46-66B). The fibers attach just below the crest on the outer table of the ilium. They have a common insertion point with both the tensor fascia lata and gluteals. The interval between the EOM and these structures needs to be identified and the intermuscular plane is incised (Fig. 46-66C). 
Figure 46-66
Approach to SI joint from anterior.
 
A: Anterior approach. B: Incision to subcutaneous tissue. C: Muscle fibers seen with in the intermuscular plane between the external oblique muscles (EOM) and the tensor/gluteal common origin. D, E: EOM is then subperiosteally elevated utilizing a Cobb elevator and iliac fossa exposed. F: SI joint exposed and visualized (arrow pointing to cartilage of sacrum). G: Complete exposure of the SI joint.
A: Anterior approach. B: Incision to subcutaneous tissue. C: Muscle fibers seen with in the intermuscular plane between the external oblique muscles (EOM) and the tensor/gluteal common origin. D, E: EOM is then subperiosteally elevated utilizing a Cobb elevator and iliac fossa exposed. F: SI joint exposed and visualized (arrow pointing to cartilage of sacrum). G: Complete exposure of the SI joint.
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A: Anterior approach. B: Incision to subcutaneous tissue. C: Muscle fibers seen with in the intermuscular plane between the external oblique muscles (EOM) and the tensor/gluteal common origin. D, E: EOM is then subperiosteally elevated utilizing a Cobb elevator and iliac fossa exposed. F: SI joint exposed and visualized (arrow pointing to cartilage of sacrum). G: Complete exposure of the SI joint.
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A: Anterior approach. B: Incision to subcutaneous tissue. C: Muscle fibers seen with in the intermuscular plane between the external oblique muscles (EOM) and the tensor/gluteal common origin. D, E: EOM is then subperiosteally elevated utilizing a Cobb elevator and iliac fossa exposed. F: SI joint exposed and visualized (arrow pointing to cartilage of sacrum). G: Complete exposure of the SI joint.
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Figure 46-66
Approach to SI joint from anterior.
A: Anterior approach. B: Incision to subcutaneous tissue. C: Muscle fibers seen with in the intermuscular plane between the external oblique muscles (EOM) and the tensor/gluteal common origin. D, E: EOM is then subperiosteally elevated utilizing a Cobb elevator and iliac fossa exposed. F: SI joint exposed and visualized (arrow pointing to cartilage of sacrum). G: Complete exposure of the SI joint.
A: Anterior approach. B: Incision to subcutaneous tissue. C: Muscle fibers seen with in the intermuscular plane between the external oblique muscles (EOM) and the tensor/gluteal common origin. D, E: EOM is then subperiosteally elevated utilizing a Cobb elevator and iliac fossa exposed. F: SI joint exposed and visualized (arrow pointing to cartilage of sacrum). G: Complete exposure of the SI joint.
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A: Anterior approach. B: Incision to subcutaneous tissue. C: Muscle fibers seen with in the intermuscular plane between the external oblique muscles (EOM) and the tensor/gluteal common origin. D, E: EOM is then subperiosteally elevated utilizing a Cobb elevator and iliac fossa exposed. F: SI joint exposed and visualized (arrow pointing to cartilage of sacrum). G: Complete exposure of the SI joint.
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A: Anterior approach. B: Incision to subcutaneous tissue. C: Muscle fibers seen with in the intermuscular plane between the external oblique muscles (EOM) and the tensor/gluteal common origin. D, E: EOM is then subperiosteally elevated utilizing a Cobb elevator and iliac fossa exposed. F: SI joint exposed and visualized (arrow pointing to cartilage of sacrum). G: Complete exposure of the SI joint.
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The EOM is then subperiosteally elevated off and over the crest utilizing a Cobb elevator and continued down onto the inner table. The iliac fossa is entered and the iliacus is elevated off the inner table. At this point osseous bleeding occurs from the many large nutrient vessels that are disrupted as the iliacus is elevated (Fig. 46-66D, E). Bone wax is often used to control the bleeding by occluding the nutrient foramen. In addition, laps soaked in thrombin can be placed into the iliac fossa to tamponade these vessels. If the approach is being performed for iliac wing fractures, further exposure onto the sacrum is unnecessary and the iliac wing fracture should be fully visualized. Fixation can follow. 
As the dissection is continued medially, the psoas is elevated over the pelvic brim allowing access into the true pelvis. A malleable retractor, radiolucent if available, is placed over the brim to retract the abdominal and pelvic contents. Often the iliopsoas is tight and placing a sterile bump under the prepped in leg can take tension off the musculature, making exposure easier. At this point the SI joint usually is wide open and the lateral aspect of the sacrum (medial aspect of SI joint) with its cartilage is visualized (Fig. 46-66F). Care must be taken to assess for the rare occurrence of the L5 nerve root being displaced into the SI joint. 
The dissection should continue up over the sacrum onto the ala carefully so as not to injure the L5 nerve root, which is usually lying about 1 cm medial to the SI joint, intimate with the bone. Attempts should be made to keep the dissection subperiosteally, which will help protect the nerve from injury. Often the nerve can be palpated on the anterior aspect of the ala, and blunt dissection with a finger can gently push the nerve out of harm’s way while the medial dissection is performed. If the approach is being used to extricate the L5 nerve root from the sacral fracture, extreme caution must be exercised when elevating medially onto the sacrum. Once the nerve is identified and protected, and the ala exposed, a sharp Hohmann retractor can be placed into the ala. This should be performed under direct visualization. The superior portion of the SI joint is now fully exposed and reduction maneuvers can be performed (Fig. 46-65G). 

ORIF Iliac Wing Fractures

Surgical Technique.
Once exposure of the iliac wing fracture has been obtained, from either a posterior or anterior approach, the fracture can be reduced. Reduction can be difficult, since the ilium is essentially a flat bone. A Weber or small pointed reduction clamps placed across the fracture site at the crest, utilizing pilot holes for tine placement, is extremely useful. A ball spike with a footplate attachment can be used to push the displaced ilium to the stable ilium to aid in the reduction. A CMF clamp (see Fig. 46-52A), which has parallel tines, is also useful in flat bones and allows fracture surfaces to be brought together. Fixation can now be placed after the reduction has been obtained (Fig. 46-67A–D). 
Figure 46-67
 
A: Iliac wing fracture anatomically reduced with CMF clamp. B–D ORIF of iliac wing fracture with plate and iliac wing screw (black arrow).
A: Iliac wing fracture anatomically reduced with CMF clamp. B–D ORIF of iliac wing fracture with plate and iliac wing screw (black arrow).
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A: Iliac wing fracture anatomically reduced with CMF clamp. B–D ORIF of iliac wing fracture with plate and iliac wing screw (black arrow).
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Figure 46-67
A: Iliac wing fracture anatomically reduced with CMF clamp. B–D ORIF of iliac wing fracture with plate and iliac wing screw (black arrow).
A: Iliac wing fracture anatomically reduced with CMF clamp. B–D ORIF of iliac wing fracture with plate and iliac wing screw (black arrow).
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A: Iliac wing fracture anatomically reduced with CMF clamp. B–D ORIF of iliac wing fracture with plate and iliac wing screw (black arrow).
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Because the central portion of the wing is often thin, plates and screws should be placed along the crest (anterior approaches [Fig. 46-67D] or posterior approaches [Fig. 46-67B]), along the pelvic brim just adjacent to the SI joint (anterior approach [Fig. 46-67D]) or at the level of the sciatic buttress (posterior approach). Lag screws along the crest are useful for providing both fixation and compression of the fracture. In general, two plates are used to aid in healing by neutralizing any deforming forces303,305,337 (Fig. 46-67D). 
Closure is performed in layers, with the EOM or TGM reattached to the iliac crest with a heavy absorbable suture (0 Vicryl). A drain is placed underneath the muscle and brought out away from the incision. The subcutaneous tissue is closed with 2-0 Vicryl, and the skin is closed with staples. A sterile dressing is applied. 
Postoperative Care.
Postoperatively, toe touch weightbearing restrictions are placed on the side of the iliac wing fracture for 12 weeks. The drain is removed generally at 48 hours, and prophylactic antibiotics are continued during this time and discontinued at time of drain removal. DVT prophylaxis is used for at least 6 weeks and is ultimately dependent on the patient’s associated injuries and mobility status. Staples or sutures are removed at 2 weeks. 
Potential Pitfalls and Preventive Measures.
Poor screw purchase is often a problem due to the thin nature of the ilium. Care must be taken to place the plates and screws adjacent to the crest to take advantage of the thicker bone at the periphery. Placing lag screws between the tables is also useful, but care must be taken to avoid in–out placement in the central, thin portion of the wing. Placement of clamps in this central area is also fraught with problems and may cause more comminution. Clamps should be confined to the crest, pelvic brim, and the sciatic buttress area. 
Due to the relative subcutaneous nature of the iliac crest, iliac wing fractures may be open, necessitating more urgent or emergent management. Careful clinical examination must be performed so as not to miss any open wounds. These injuries have also been associated with entrapped bowel,43,75,334 which can be overlooked. The CT scan should be carefully examined for signs of air tracking to the fracture or bowel injury; addition of enteric contrast may be needed to help elucidate bowel involvement.334 Failure to recognize these injuries can lead to infection and possible osteomyelitis of the ilium. Such open fractures with fecal contamination may require serial debridement with open packing and delayed closure. 
Treatment-Specific Outcomes.
No large series of isolated iliac wing fractures have been reported to date. In one small series, it was clear that associated injuries complicate outcomes.337 In general, most heal and the fracture itself does not seem to cause long-term issues. If operative intervention was required through an anterior approach (lateral window), occasional injury to the lateral femoral cutaneous nerve may cause lateral thigh numbness. Excessive traction on the nerve during retraction and fixation may lead to meralgia paresthetica. The author preoperatively obtains written informed consent from the patient for transection of the lateral femoral cutaneous nerve as needed so as to prevent this complication. Patients have little issue with a small area of thigh numbness versus pain from the dysesthesia.67 

Surgical Management of Crescent Fractures (Fracture–Dislocations)

The management of the crescent fracture, an iliac wing fracture that exits into the SI joint with resultant SI dislocation,22,23 can be approached from posterior as described previously. These fractures occur with some disruption of the SI ligament complex. The fragment of bone that includes the PSIS and PIIS is termed the crescent fragment. It usually remains attached to the sacrum by the posterior SI ligaments, sometimes along with the intraarticular SI ligaments. The ilium is generally the displaced part of the fracture because the anterior SI ligaments are disrupted. Because the size of the crescent fragment is variable, implant stabilization is individualized. Day et al.61 described a functional classification for crescent fracture dislocations of the sacroiliac joint. They divided the SI joint into thirds (types 1, 2, and 3) starting from anterior to posterior. This subclassification of the LC II injury aids the surgeon in the surgical approach and technique. The type II injury involves the middle third of the joint and often needs a posterior approach. 
Surgical Technique.
Once the posterior ilium is exposed, as described previously, the fracture site should be encountered. Adequate exposure of the notch is necessary for both visualization of the entire fracture and placement of clamps through the notch to allow reduction of the anterior aspect of the SI joint. Exposure of this inferior margin also enables plate application along the sciatic buttress. At this point, reduction and fixation can be accomplished. 
Because the crescent fragment is the equivalent of the “constant fragment” in calcaneus fractures, the first goal is to reduce the displaced ilium to this anatomically located fragment. A ball spike pusher with a footplate can help reduce the ilium to the crescent fragment by applying inward and downward pressure on the outside of the laterally and posteriorly translated ilium. Several methods can be used to hold the reduction while definitive fixation is applied. 
A Weber reduction clamp from the PSIS to the ilium can stabilize the reduction. Temporary K-wires can be placed from the PSIS into the ilium parallel to the SI joint until definitive fixation can be accomplished. An offset reduction clamp can be placed inferiorly through the notch, with one tine placed onto the lateral sacral ala and the other placed onto the lateral aspect of the displaced ilium fragment. To aid placement of the anterior tine, simultaneous finger palpation should be used to ensure that the tine is not placed into the foramen or nerve roots. 
Lag screws from the PIIS directed toward the sciatic buttress just above the greater notch allow for excellent compression and stabilization of the fracture. The screws generally are parallel to the SI joint (Fig. 46-68A, B). Application of a 3.5 mm pelvic reconstruction can be placed along the iliac crest to aid in fixation and act as a neutralization plate, although the author has successfully used multiple lag screws alone (Fig. 46-69A–C). 
Figure 46-68
Patient with crescent fracture.
 
A: Injury CT scan showing fracture. B: Postoperative CT scan showing anatomic lag screw fixation parallel to SI joint.
A: Injury CT scan showing fracture. B: Postoperative CT scan showing anatomic lag screw fixation parallel to SI joint.
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Figure 46-68
Patient with crescent fracture.
A: Injury CT scan showing fracture. B: Postoperative CT scan showing anatomic lag screw fixation parallel to SI joint.
A: Injury CT scan showing fracture. B: Postoperative CT scan showing anatomic lag screw fixation parallel to SI joint.
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Figure 46-69
Patient with LC II pelvic ring injury.
 
A: CT axial cut showing crescent fracture. B: A 3D CT iliac oblique view showing extent of iliac wing fracture. C: Two-year follow-up with successful healing with lag screw fixation posteriorly.
A: CT axial cut showing crescent fracture. B: A 3D CT iliac oblique view showing extent of iliac wing fracture. C: Two-year follow-up with successful healing with lag screw fixation posteriorly.
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Figure 46-69
Patient with LC II pelvic ring injury.
A: CT axial cut showing crescent fracture. B: A 3D CT iliac oblique view showing extent of iliac wing fracture. C: Two-year follow-up with successful healing with lag screw fixation posteriorly.
A: CT axial cut showing crescent fracture. B: A 3D CT iliac oblique view showing extent of iliac wing fracture. C: Two-year follow-up with successful healing with lag screw fixation posteriorly.
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If the crescent fragment is small as in the type III injury, the fracture line is generally posterior to the normal starting point of an iliosacral screw and thus the injury can be treated like an SI joint dislocation and an SI screw placed. The iliac wing should still be reduced anatomically to the small crescent fragment prior to SI stabilization. If the small fragment is large enough to accommodate one or two lag screws from the PIIS, they can be placed to fix the wing portion (Fig. 46-70A–C). The SI screw(s) are then used to reduce and stabilize the SI joint, if needed. 
Figure 46-70
Patient with LC II pelvic ring injury with small posterior crescent fracture.
 
A: CT axial cut showing crescent fracture on left. B: A 3D CT posterior view showing small crescent fracture. C: Six-month follow-up with successful healing with lag screw fixation posteriorly.
A: CT axial cut showing crescent fracture on left. B: A 3D CT posterior view showing small crescent fracture. C: Six-month follow-up with successful healing with lag screw fixation posteriorly.
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Figure 46-70
Patient with LC II pelvic ring injury with small posterior crescent fracture.
A: CT axial cut showing crescent fracture on left. B: A 3D CT posterior view showing small crescent fracture. C: Six-month follow-up with successful healing with lag screw fixation posteriorly.
A: CT axial cut showing crescent fracture on left. B: A 3D CT posterior view showing small crescent fracture. C: Six-month follow-up with successful healing with lag screw fixation posteriorly.
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In contrast, a large crescent fragment (type I) should be stabilized like any other iliac wing fracture; it should be approached from the front. The amount of SI joint involvement is relatively small. An SI screw will not stabilize the displaced ilium, and serves only to stabilize an already reduced and intact SI joint. Lag screws can be used in the same manner as for other crescent fractures. Because the large crescent fragment is attached to the sacrum through both the posterior and intraarticular ligaments, fixation to the wing alone is sufficient (Fig. 46-71A–G). 
Figure 46-71
Patient with LC II pelvic ring injury with large iliac crest fracture.
 
A: Injury AP. B: CT axial cut showing iliac wing involvement. C, D: A 3D CT iliac oblique view and posterior view showing extent of iliac wing involvement. E–G: Six-month follow-up after successful healing with ORIF from anterior approach (same patient as in Figure 46-67C, D).
A: Injury AP. B: CT axial cut showing iliac wing involvement. C, D: A 3D CT iliac oblique view and posterior view showing extent of iliac wing involvement. E–G: Six-month follow-up after successful healing with ORIF from anterior approach (same patient as in Figure 46-67C, D).
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A: Injury AP. B: CT axial cut showing iliac wing involvement. C, D: A 3D CT iliac oblique view and posterior view showing extent of iliac wing involvement. E–G: Six-month follow-up after successful healing with ORIF from anterior approach (same patient as in Figure 46-67C, D).
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Figure 46-71
Patient with LC II pelvic ring injury with large iliac crest fracture.
A: Injury AP. B: CT axial cut showing iliac wing involvement. C, D: A 3D CT iliac oblique view and posterior view showing extent of iliac wing involvement. E–G: Six-month follow-up after successful healing with ORIF from anterior approach (same patient as in Figure 46-67C, D).
A: Injury AP. B: CT axial cut showing iliac wing involvement. C, D: A 3D CT iliac oblique view and posterior view showing extent of iliac wing involvement. E–G: Six-month follow-up after successful healing with ORIF from anterior approach (same patient as in Figure 46-67C, D).
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A: Injury AP. B: CT axial cut showing iliac wing involvement. C, D: A 3D CT iliac oblique view and posterior view showing extent of iliac wing involvement. E–G: Six-month follow-up after successful healing with ORIF from anterior approach (same patient as in Figure 46-67C, D).
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After fixation is completed, the wound is irrigated and a drain placed deep to the gluteal musculature. Closure is performed in layers, with the TGM, reattached to the iliac crest with a heavy absorbable suture (0 Vicryl). The subcutaneous tissue is closed with 2-0 Vicryl, and a subcuticular skin closure is performed followed by Dermabond tape. A sterile dressing is applied. 
Optional Method: Type I Fractures.
An alternative method of fixation using closed reduction and percutaneous screw fixation has been described.324 This can be performed on iliac wing fractures close to the SI joint or with iliac fracture-dislocations in which the crescent fragment is large. Paramount to use of this technique is the ability to obtain a closed reduction of the fracture. 
The patient can be positioned either prone or supine. Advantages of supine positioning are that it allows for easier application of an external rotation force to be applied to the ilium. This can be applied by manual manipulation of the hemipelvis by direct force on the ASIS, placing the leg in Flexion, ABduction, and External Rotation (FABER exam), or placing a Schanz pin in the iliac crest. The reduction can be aided with a percutaneous ball spike placed on the lateral ilium. This should be performed with fluoroscopy to ensure that it is placed in a safe area and onto the lateral ilium. 
Reduction is confirmed by radiographic imaging, using the obturator and iliac oblique views as well as a view directed down the SI joint. The teardrop view as described in the section on supra-acetabular external fixation is used to determine the appropriate starting point at the AIIS. A small incision is made and a guide pin for a large diameter cannulated screw system is then directed from the AIIS to the PIIS across the fracture (reverse if prone). The guide pin is advanced under the iliac oblique view, and stopped just short of penetrating out the PIIS. It is measured and an appropriate length partially threaded screw is placed. Two or three screws can be placed. 
Solid 3.5 or 4.5 mm screws can also be used, but can be technically challenging, since a drill bit is used instead of a guide wire. If solid screws are used, they should be put in using standard AO technique for lag screws (Fig. 46-72). 
Figure 46-72
 
A: Large crescent fracture, B: Large crescent fracture stabilized with LC-II screw running from AISS to PIIS.
A: Large crescent fracture, B: Large crescent fracture stabilized with LC-II screw running from AISS to PIIS.
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Figure 46-72
A: Large crescent fracture, B: Large crescent fracture stabilized with LC-II screw running from AISS to PIIS.
A: Large crescent fracture, B: Large crescent fracture stabilized with LC-II screw running from AISS to PIIS.
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If closed reduction fails, ORIF should be performed. Because the technique is limited to certain fracture patterns, supine positioning is usually not a problem, since the treatment should be similar to that of an iliac wing fracture from the anterior approach. If the patient was placed prone, the posterior approach described previously can be utilized. Closure is minimal for the percutaneous technique. No drains are necessary. 
Postoperative Care.
Postoperatively, toe touch weightbearing restrictions are placed on the side of the crescent fracture for 12 weeks. The drain is removed generally at 48 hours, and prophylactic antibiotics are continued during this time and discontinued at the time of drain removal. DVT prophylaxis is used for at least 6 weeks and is ultimately dependent on the patient’s associated injuries and mobility status. Staples are removed at 2 weeks. 
Potential Pitfalls and Preventive Measures.
Failure to appreciate the size of the crescent fragment can lead to inadequate or improper fixation. If the fragment is believed to be larger than it is, the need for SI joint stabilization may be felt to be unnecessary. This may lead to persistent SI joint instability. Careful preoperative evaluation of the CT scan and obtaining 3D reconstruction can clarify the injury pattern. The location of the fracture line can better be visualized. This will aid in the determination of the need for SI joint stabilization as well as help with preoperative implant selection. The converse is true as well. If the fragment is felt to be smaller than it is, it may not be possible to perform screw placement, since the fracture line may be at the level of the starting point for screw insertion. 
Because the mechanism of injury is lateral compression, it can be difficult to reduce the fracture, since an external rotation force must be applied to the iliac wing in the prone position. In the supine position, Schanz pins placed into the hemipelvis can be used to distract and correct the internal rotation deformity. However, this is not possible in the prone position. To correct the internal rotation deformity, a lamina spreader can be inserted into the fracture site gapping it open. A ball spike with a footplate can be used simultaneously to push the ilium down and inward. This should be done adjacent to the fracture site such that an external rotation force is being indirectly applied to the ilium by the sacral ala as the SI joint is reduced. Prepping in the entire leg can also aid in the reduction. Flexing the knee and rotating the foot toward the midline will externally rotate the ilium. 
Lag screws can inadvertently be placed into the SI joint if the trajectory is off. Adequate intraoperative imaging looking down the SI joint can ensure that the lag screw is placed within the confines of the posterior iliac crest. 
Percutaneous techniques should be performed after experience is obtained in a cadaveric setting. Familiarizing oneself with the special views needed and how to obtain them is also helpful. Accurate assessment of the closed reduction with fluoroscopy is required to ensure that appropriate treatment has been rendered. If the reduction is not obtained closed, then the procedure should be converted to an open procedure without hesitation. 
Treatment-Specific Outcomes.
There is little information about the functional outcomes in a single type of pelvic ring fracture group as classified by Young and Burgess. The majority of studies encompass all types of unstable ring injuries and various surgical approaches.120,144,269,360 A recent study looking at all operatively treated unstable LC patterns shows that the majority of patients do have persistent impairment and long-term disability based on Short Musculoskeletal Function Assessment SMFA scores.131 Although in their study polytrauma patients were similar to nonpolytrauma patients, associated lower extremity injuries had worse outcomes. However, a study by Day et al.61 looked specifically at LC II injuries. They used the SF-36 and Musculoskeletal Function Assessment (MFA) scores to evaluate functional outcome. All fractures united, with only one malunion, in the consecutive series of 16 patients. All patients achieved good functional results at 2 years from the injury. Associated injuries were found to have more of an effect on the SF-36 and MFA than the pelvic injury itself, with patients having multiple injuries doing worse. 

Sacroiliac Joint Dislocations

Iliosacral Screw Fixation

Iliosacral screw fixation requires experience and an understanding of intraoperative fluoroscopic imaging and its relationship to anatomic structures to prevent complications. The surgeon must recognize abnormal anatomy in patients with sacral dysmorphism so as to prevent inadvertent injury to neurovascular structures.3,37,50,73,277,278,341 Iliosacral screws have become increasingly useful for stabilization of SI joint injuries, despite their equivocal biomechanical strength when compared to transiliac fixation or anterior SI plating. Iliosacral screw fixation is minimally invasive, making it useful for percutaneous methods either in the supine or prone positions if the soft tissues prevent formal open reduction of the SI joint either anterior or posterior. The successful use of an SI screw is predicated on successful closed reduction of the SI joint, although an open reduction of the SI joint can be performed if need be and percutaneous placement of an SI screw can still be accomplished. The use of SI screws has become the most common procedure for stabilization of the unstable SI joint as well as for sacral fractures amenable to such treatment, whereas other techniques have been reserved for salvage situations such as in fixation failures.149,299 Anterior SI plating308 and transiliac fixation52,112,162,298,376 have their roles in the treatment of pelvic ring injuries, but they require larger exposures. In addition there is no biomechanical advantage of these procedures over that of SI screw fixation.52,112,298,376 
Iliosacral screw placement is generally performed in the supine position, although in certain situations percutaneous screws can be placed in the prone position. This is for cases where an open reduction of the SI joint or crescent fracture may be needed and the screw can be placed percutaneously. Closed reduction of the pelvic ring can be accomplished with the IRTOTLE technique94 or a sheet wrapped around the level of the greater trochanters. A similar technique of using a circumferential wrap around the pelvis while cutting out holes for iliosacral screw placement is helpful.93 This method is useful when the reduction can be performed closed; however, if an open reduction is required, the sheet will be in the way of any incisions that may be needed. 
The surgeon must be familiar with all radiographic landmarks and the bony anatomy for safe placement of an SI screw. The mandatory intraoperative images are the inlet and outlet views.374 A lateral sacral view is useful to determine the starting point prior to prepping of the hip area, or it can be obtained after prepping.277 However, one must be familiar with all views to safely place an iliosacral screw. Often visualization may be obscured or is suboptimal, and familiarity with all views can aid the surgeon in safe placement. Patient factors that can prevent visualization are obesity and significant bowel gas. Taping of the pannus can aid visualization and nasogastric or orogastric tubes at low wall suction can decrease the bowel gas at times. An experienced radiology technician is also a necessity to decrease frustration and radiation exposure, which will improve overall efficiency and safety of the procedure. 
Use of a lateral sacral fluoroscopic view in the lab has been shown to improve the accuracy of screw placement, and decrease placement time and radiation exposure.106 The bony landmarks corresponding to the lateral radiographic projection are shown in Figure 46-73. Although not routine for many experienced pelvic surgeons, the lateral fluoroscopic image can be helpful early on in one’s career. These bony landmarks are important to understand the areas one wants to avoid. The posterior aspect of the S1 body corresponds to the anterior aspect of the spinal canal. The iliac cortical density corresponds to the sacral ala on which the L5 nerve rests. Anterior to the anterior cortex of the sacral promontory is where the great vessels lie, and these can be perforated. The residual disk space between S1 and S2 is where the S1 foramen and nerve root lie. The safe area for placement of a screw is marked on the skin and this will correspond to the starting area (Fig. 46-74A, B). 
Figure 46-73
Lateral fluoroscopic projection showing bony landmarks for placement of iliosacral screw.
 
Dashed black line indicated anterior aspect of sacral canal. Red dotted square shows area for placement of screw as indicated by tip of guide wire.
Dashed black line indicated anterior aspect of sacral canal. Red dotted square shows area for placement of screw as indicated by tip of guide wire.
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Figure 46-73
Lateral fluoroscopic projection showing bony landmarks for placement of iliosacral screw.
Dashed black line indicated anterior aspect of sacral canal. Red dotted square shows area for placement of screw as indicated by tip of guide wire.
Dashed black line indicated anterior aspect of sacral canal. Red dotted square shows area for placement of screw as indicated by tip of guide wire.
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Figure 46-74
 
A: Fluoroscopic lateral projections with superimposed guide wire to aid in marking the skin. B: Clinical picture of lateral sacral projection drawn on skin (shaded box indicates starting point corresponding to area in Figure 46-72).
A: Fluoroscopic lateral projections with superimposed guide wire to aid in marking the skin. B: Clinical picture of lateral sacral projection drawn on skin (shaded box indicates starting point corresponding to area in Figure 46-72).
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Figure 46-74
A: Fluoroscopic lateral projections with superimposed guide wire to aid in marking the skin. B: Clinical picture of lateral sacral projection drawn on skin (shaded box indicates starting point corresponding to area in Figure 46-72).
A: Fluoroscopic lateral projections with superimposed guide wire to aid in marking the skin. B: Clinical picture of lateral sacral projection drawn on skin (shaded box indicates starting point corresponding to area in Figure 46-72).
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Placement of the SI screw is performed using the inlet and outlet fluoroscopic projections. The c-arm technician must be facile in switching between these two views, otherwise the procedure can take longer than it should. In rare instances, when two c-arms can be obtained, they can be set up opposite each other to provide simultaneous imaging with both inlet and outlet projections, thereby allowing increased efficiency for placement of the screw (Fig. 46-75A, B). Some have entertained the idea of using surgical navigation systems in placement of iliosacral screws. These systems have been tried in cadavers with some success.51,62,136,314 The setup time required to perform such procedures is considerable, and obtaining image quality that is sufficient for tracking and the actual navigation has been problematic. An additional method is to utilize CT scanned navigation for placement of SI screws.273,280,327 This requires a CT setup in the operating room, which can be extremely expensive. 
Figure 46-75
Setup for utilizing two simultaneous c-arms.
 
A: Monitor setup showing inlet view (left) and outlet view (right). B: Actual c-arms in position for the procedure: left view showing c-arms and monitors and right view from surgeon’s perspective showing preferential placement of inlet view c-arm on the side of the operative field allowing easier access for placement of screw (black circle).
A: Monitor setup showing inlet view (left) and outlet view (right). B: Actual c-arms in position for the procedure: left view showing c-arms and monitors and right view from surgeon’s perspective showing preferential placement of inlet view c-arm on the side of the operative field allowing easier access for placement of screw (black circle).
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Figure 46-75
Setup for utilizing two simultaneous c-arms.
A: Monitor setup showing inlet view (left) and outlet view (right). B: Actual c-arms in position for the procedure: left view showing c-arms and monitors and right view from surgeon’s perspective showing preferential placement of inlet view c-arm on the side of the operative field allowing easier access for placement of screw (black circle).
A: Monitor setup showing inlet view (left) and outlet view (right). B: Actual c-arms in position for the procedure: left view showing c-arms and monitors and right view from surgeon’s perspective showing preferential placement of inlet view c-arm on the side of the operative field allowing easier access for placement of screw (black circle).
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Surgical Technique.
Once the starting point has been established on the lateral view, the guide wire is inserted into the soft tissues. The entry should be below the iliac-cortical density at the posterior cortex of the S1 body. Either a drill-tipped guide wire or threaded-tipped guide wire can be used, although the former is preferred by many pelvic surgeons due to its ease in redirection. 
Either the inlet or outlet view can first be obtained determining the anterior or posterior or superior or inferior position of the starting point, respectively. The inlet projection (Fig. 46-76) is extremely helpful for ensuring that the path of the screw does not penetrate the anterior aspect of the sacral promontory, which could inadvertently penetrate the vessels. In addition it will ensure that there is no posterior violation of the cortex, which would result in injury to the nerve roots or the cauda equina. The outlook projection (Fig. 46-77) ensures that there is no penetration into the S1 foramen below and that the screw is heading either toward the endplate of S1 or into the S1 body. The outlet projection also ensures that the screw can be placed through and through across the opposite SI joint if bilateral fixation is needed in cases of bilateral sacral fractures. 
Figure 46-76
Fluoroscopic inlet image showing pin and planned trajectory.
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Figure 46-77
Sacral foramina are outlines in red.
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Figure 46-77
Fluoroscopic outlet image showing pin and planned trajectory.
Sacral foramina are outlines in red.
Sacral foramina are outlines in red.
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It is important to realize that stabilization of an SI joint requires perpendicular placement of an iliosacral screw across that SI joint. It is similar to any type of fracture fixation where the lag screw should be placed perpendicular to obtain anatomic reduction and compression of the fracture itself. The SI screw itself can act as a reduction guide in cases where residual displacement still is present, and therefore the reduction will be directed along that tract (Fig. 46-78). If there is malpositioning of the SI screw then inadvertent malreduction of the SI joint can occur in the direction of the malpositioned SI screw. This principle can be used to the surgeon’s advantage to reduce minor residual deformities. If the screw trajectory is properly planned to reduce the subtle residual displacements, the screw can be used to actually reduce the SI joint anatomically. Realize that the “safe corridor” for SI screw placement must be adhered to and this technique is for advanced pelvic surgeons. 
Figure 46-78
Fluoroscopic images showing gap of left SI joint and reduction with iliosacral screw perpendicular to SI joint.
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Fixation is performed with partially threaded cannulated screws. Diameters of 6.5 mm, 7.3 mm, or 8.0 mm have all been used to stabilize these SI joint dislocations. In certain sacral fractures, fully threaded screws may be used (see Sacral Fracture section). Screws may be placed with or without washers; my preference is for a spherical washer that sits against the lateral ilium in an oblique fashion. In addition, washers can help in situations where osteoporotic bone may allow for inadvertent perforation of the screw head. The screw size is determined by the room available as well as whether bilateral fixation is needed. If a through and through screw can be placed across both SI joints (Fig. 46-79A, B; if anatomic reductions have been obtained) then a larger single screw may be utilized. However in situations where bilateral SI joint dislocations require open reduction and separate fixation, smaller screws (6.5 mm) may be utilized to allow for adequate room in the S1 body for two screws coming in from opposite directions. This is more often the scenario when bilateral SI joint dislocations are encountered (Fig. 46-80). 
Figure 46-79
 
A: Sequential fluoroscopic images showing reduction of contralateral SI joint with a screw for a through and through iliosacral screw placement in bilateral SI joint injuries. B: AP pelvis view showing final stabilization.
A: Sequential fluoroscopic images showing reduction of contralateral SI joint with a screw for a through and through iliosacral screw placement in bilateral SI joint injuries. B: AP pelvis view showing final stabilization.
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Figure 46-79
A: Sequential fluoroscopic images showing reduction of contralateral SI joint with a screw for a through and through iliosacral screw placement in bilateral SI joint injuries. B: AP pelvis view showing final stabilization.
A: Sequential fluoroscopic images showing reduction of contralateral SI joint with a screw for a through and through iliosacral screw placement in bilateral SI joint injuries. B: AP pelvis view showing final stabilization.
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Figure 46-80
Outlet view of patient with bilateral SI joint injuries stabilized with bilateral iliosacral screws 1 year postoperatively.
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The guide wire should be advanced to a point just adjacent or lateral to the sacral S1 foramen when utilizing the outlet view. The image can be switched from outlet to inlet to ensure that the guide wire is still heading in the proper trajectory toward the S1 body and not out the anterior or posterior aspect of the ala or the body. The L5 nerve root is at risk and keeping the pin close to S1 on the outlet view can help avoid going in-out-in. Most pelvic surgeons stop the guide wire into the body itself. Placement of the guide wire all the way across into the opposite ala can be suboptimal due to the quality of bone density. In addition, the contralateral L5 nerve root may be at risk. Therefore long thread lengths with the tip of the screw in the sacral body and promontory have been shown to offer the greatest resistance to pull out.37,160 Some have recommended that the SI screw be placed as close to the superior end plate and anterior aspect of S1 to stay as far away from the S1 foramen as possible.285 
Once the guide wire is placed in its proper position, the depth of the guide wire can be measured and subsequently a partially threaded cancellous cannulated screw can be placed over the wire. A washer is used for SI joint dislocations to allow for reduction and compression, and to avoid and prevent penetration of the screw head through the lateral ilium. In young patients with excellent bone, the cannulated drill should be used to perforate the lateral ilium, inner ilium, and the outer sacrum prior to placement of the screw. After placement, a lateral projection in addition to the standard AP, inlet, and outlet fluoroscopic projections can be obtained to confirm proper placement of the screw in the S1 corridor (Fig. 46-81A, B). 
Figure 46-81
 
A: Lateral fluoroscopic projection of iliosacral screw (with washer) demonstrating proper placement and screw within confines of S1 corridor. B: Different patient with “shot” down the center of the screw (no washer) confirming safe placement of the screw.
A: Lateral fluoroscopic projection of iliosacral screw (with washer) demonstrating proper placement and screw within confines of S1 corridor. B: Different patient with “shot” down the center of the screw (no washer) confirming safe placement of the screw.
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Figure 46-81
A: Lateral fluoroscopic projection of iliosacral screw (with washer) demonstrating proper placement and screw within confines of S1 corridor. B: Different patient with “shot” down the center of the screw (no washer) confirming safe placement of the screw.
A: Lateral fluoroscopic projection of iliosacral screw (with washer) demonstrating proper placement and screw within confines of S1 corridor. B: Different patient with “shot” down the center of the screw (no washer) confirming safe placement of the screw.
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A second SI screw can be placed into the S1 level if there is enough room available in the S1 body or at the S2 level if it is felt that the first SI screw is less than ideal.204 Furthermore, if there is considerable instability of the pelvic ring, certain biomechanical studies have shown increased stability by placing a second screw (Fig. 46-82A, B). A second screw placed into the S2 vertebral body has been shown to be superior to a second screw placed into the S1 body.287,361 In some instances due to the patient’s sacral dysmorphism, placement of a S1 screw is impossible and therefore placement into the S2 level is warranted. This often is the case when there is either lumbarization of S1 or sacralization of L5. The placement of an S2 screw in the dysmorphic pelvis has been found to be safe59,91 (Fig. 46-83A–C). 
Figure 46-82
 
A: Injury 3D outlet view of patient with right sided SI joint disruption and L5 transverse process fracture. B: Postoperative outlet view with placement of S1 and S2 screws showing anatomic stabilization of SI joint.
A: Injury 3D outlet view of patient with right sided SI joint disruption and L5 transverse process fracture. B: Postoperative outlet view with placement of S1 and S2 screws showing anatomic stabilization of SI joint.
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Figure 46-82
A: Injury 3D outlet view of patient with right sided SI joint disruption and L5 transverse process fracture. B: Postoperative outlet view with placement of S1 and S2 screws showing anatomic stabilization of SI joint.
A: Injury 3D outlet view of patient with right sided SI joint disruption and L5 transverse process fracture. B: Postoperative outlet view with placement of S1 and S2 screws showing anatomic stabilization of SI joint.
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Figure 46-83
 
A: Injury outlet view of patient with dysmorphic sacrum and left sided APC II injury. B: Injury 3D outlet view. C: Stabilization of left SI joint with S2 screw owning to inability to place S1 screw because of sacral dysmorphism. An additional alar screw is shown that aided in directional reduction.
A: Injury outlet view of patient with dysmorphic sacrum and left sided APC II injury. B: Injury 3D outlet view. C: Stabilization of left SI joint with S2 screw owning to inability to place S1 screw because of sacral dysmorphism. An additional alar screw is shown that aided in directional reduction.
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Figure 46-83
A: Injury outlet view of patient with dysmorphic sacrum and left sided APC II injury. B: Injury 3D outlet view. C: Stabilization of left SI joint with S2 screw owning to inability to place S1 screw because of sacral dysmorphism. An additional alar screw is shown that aided in directional reduction.
A: Injury outlet view of patient with dysmorphic sacrum and left sided APC II injury. B: Injury 3D outlet view. C: Stabilization of left SI joint with S2 screw owning to inability to place S1 screw because of sacral dysmorphism. An additional alar screw is shown that aided in directional reduction.
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A preoperative CT scan is a necessity prior to surgical intervention on any pelvic ring fracture. Careful attention is warranted to plan out the trajectory of the SI screw. Sacral dysmorphism and other abnormalities can easily be seen on the 3D reconstructions of the CT scan (Figs. 46-32B and 46-83B). This is paramount because the geometry and diameter of the safe corridor placement can differ significantly among patients.37,223 It has been shown that major neurovascular structures are extremely close, even to the safe corridor and therefore are at risk for inadvertent injury.341 
Postoperative Care.
The percutaneous nature of this procedure requires minimal postoperative care of the wound. No drain is required unless there is an associated Morel-Lavallee lesion that requires separate incision, irrigation, and debridement. Nonweightbearing on the side of the iliosacral screw fixation is prescribed for approximately 3 months. Bilateral fixation requires the use of a wheelchair and total transfer care. 
Potential Pitfalls and Preventive Measures.
Excellent visualization of the pelvis with fluoroscopy is required to avoid iatrogenic injury to neurovascular structures. If adequate imaging is not possible due to soft tissue issues, bowel gas, or other reasons, the procedure either should be aborted if the preventive factor can be resolved for later surgical intervention or the procedure converted to an ORIF with plates. Nasogastric tubes or orogastric tubes on low wall suction can be used to decrease bowel gas and improve visualization. 
The effect of c-arm malrotation on iliosacral screw placement has been evaluated to ascertain the potential harm it may cause. Wolinsky and Lee371 found that there were minimal issues on placement and that a wire that was properly placed always appeared to be within the bone even on malrotated views. Incorrectly placed wires could easily be detected as being out of the bone despite malrotated views. However, imaging should be performed before the procedure and proper rotation determined using the spinous processes as a reference. At times the rotation may change based on the view. Determining the angle of each of the views with the radiologic technician and marking them on the c-arm, before starting the actual procedure, can facilitate the procedure. 
Careful evaluation of the reduction should occur prior to stabilization. If the “lag” technique is used to obtain a reduction of the SI joint, the screw should be placed perpendicular to the SI joint and the reduction critically evaluated. Preoperative pelvic imaging, both plain radiographs and CT scans, should be carefully evaluated for sacral dysmorphism as this can radically alter placement of iliosacral screws in the standard fashion. Sacral dysmorphism has been shown to occur in up to 44% of patients in various series.91,277 If sacral dysmorphism is present, several issues at the S1 level can arise: (a) Screw must be placed directed obliquely in a cephalad direction, (b) may completely prevent placement of a screw, and (c) usually prevents a through and through screw placement.53 In these cases, the S2 level has been found to be large enough for safe placement of either an iliosacral or transiliac screw.53,91 
The L5 nerve root is at risk on the superoanterior aspect of the sacral ala, it can be injured during iliosacral placement either on the side of the screw placement or on the opposite side if the screw exits out the body and anterior to the opposite ala. Careful attention to the starting point can help prevent this to ensure the screw is being placed in the safe zone. Frequently switching back and forth between outlet and inlet fluoroscopic views during placement of the guide wire or drill bit can decrease the chance of improper trajectory that could injure anterior neurovascular structures or posteriorly enter the spinal canal. Inferiorly the sacral nerve root is at risk exiting the foramen. An alternative is to utilize two c-arms, one from each side, allowing simultaneous imaging of the pelvis obtaining inlet and outlet views, which can reduce both operative times and exposure239 (see Fig. 46-75A, B). Unfortunately it is often logistically difficult to obtain two c-arms. Others have reported improved results using computer navigation and 3D imaging.379 
ORIF from Anterior Approach: Surgical Technique.
Once the anterior approach to the SI joint has been accomplished, the joint can be reduced. The entire length of the superior aspect of the sacral ala can be visualized to assess the reduction. Finger palpation of the inferior aspect of the joint is required to ensure anatomic reduction. Several methods can be used to reduce the anterior SI joint. Pointed reduction forces placed across the SI joint can reduce the fracture; a screw placed on each side of the SI joint and utilization of the Farabeuf forceps or Jungbluth clamp can reduce the joint (Fig. 46-84A–F). In cases where there is an associated symphyseal disruption/diastasis, reduction of the anterior injury can facilitate reduction of the posterior injury. The controversy is in the order of fixation. A poor reduction of the anterior ring can also preclude fixation of the posterior injury. It is important to remember that the posterior ring is the weightbearing portion of the pelvis and anatomic reduction, and stabilization of this “arch” posteriorly is the primary goal according to Letournel.175,176 Ideally, the anterior ring reduction can be performed and stabilized with a clamp or other temporary methods, which will then allow an evaluation of the posterior reduction that has occurred indirectly. Avoid rigid fixation anteriorly. If the posterior reduction is felt to be anatomic, stabilization of that injury can be performed via percutaneous techniques, or the lateral window can also be performed to fine tune the reduction. Subsequently, the anterior ring can be reduced with use of plating. 
Figure 46-84
Photographs demonstrating reduction of SI joint with various clamps placed anteriorly across SI joint for reduction.
 
A: Model with holes placed on either side of SI joint. B: Use of pointed reduction forceps to reduce SI. C: Use of CMF clamp to reduce SI. D: Model with screws placed on either side of SI joint. E: Jungbluth clamp used to reduce SI. F: Farabeuf clamp used to reduce SI.
A: Model with holes placed on either side of SI joint. B: Use of pointed reduction forceps to reduce SI. C: Use of CMF clamp to reduce SI. D: Model with screws placed on either side of SI joint. E: Jungbluth clamp used to reduce SI. F: Farabeuf clamp used to reduce SI.
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A: Model with holes placed on either side of SI joint. B: Use of pointed reduction forceps to reduce SI. C: Use of CMF clamp to reduce SI. D: Model with screws placed on either side of SI joint. E: Jungbluth clamp used to reduce SI. F: Farabeuf clamp used to reduce SI.
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Figure 46-84
Photographs demonstrating reduction of SI joint with various clamps placed anteriorly across SI joint for reduction.
A: Model with holes placed on either side of SI joint. B: Use of pointed reduction forceps to reduce SI. C: Use of CMF clamp to reduce SI. D: Model with screws placed on either side of SI joint. E: Jungbluth clamp used to reduce SI. F: Farabeuf clamp used to reduce SI.
A: Model with holes placed on either side of SI joint. B: Use of pointed reduction forceps to reduce SI. C: Use of CMF clamp to reduce SI. D: Model with screws placed on either side of SI joint. E: Jungbluth clamp used to reduce SI. F: Farabeuf clamp used to reduce SI.
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A: Model with holes placed on either side of SI joint. B: Use of pointed reduction forceps to reduce SI. C: Use of CMF clamp to reduce SI. D: Model with screws placed on either side of SI joint. E: Jungbluth clamp used to reduce SI. F: Farabeuf clamp used to reduce SI.
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After the joint is reduced, the joint can be stabilized using anterior plates, with or without SI screws or SI screws alone.308 Both techniques have been shown to be biomechanically similar.52 
The lateral window can also be used in cases of sacral fractures in which significant gapping has occurred anteriorly to the point where there is concern for the L5 nerve root becoming entrapped in the fracture site when reduction of the fracture occurs. In these cases, it is prudent to visualize the fracture from the anterior approach and to isolate the L5 nerve root and extract it from the fracture site, followed by reduction and stabilization of the sacral fracture with an SI screw. 
ORIF from Posterior Approach: Surgical Technique.
In cases where closed reduction is not possible, an open reduction can be performed. Once the SI joint is exposed from posterior, it is reduced followed by stabilization. Because the reduction is performed indirectly, as only the inferior aspect of the joint is visualized, it is imperative that one be familiar with the 3D anatomy of the SI joint, sacrum, and ilium. The anterior aspect of the joint can be palpated through the greater sciatic notch. The overall reduction can be assessed via fluoroscopy. 
Although the majority of displacement is usually in the AP and medial-lateral directions, and manipulation in those directions are required for reduction, longitudinal traction can be extremely useful. Careful radiographic evaluation of the height of the iliac crests and ischial tuberosities to ensure that the two sides are level with one another should occur. If adequate traction is being applied, the inferior aspect of the ilium at the medial part of the greater sciatic notch should match up with its recess in the lateral portion of the sacrum. 
At this point the SI joint can be reduced with a large pointed reduction clamp placed across the inferior aspect of the joint. One side is placed onto the outer table of the ilium and the other side onto the sacral spinous process or the posterior cortex of the sacrum. This allows reduction of the posteroinferior portion of the joint (Fig. 46-85). Reduction of the anterior portion of the joint requires a second offset pelvic clamp placed through the greater sciatic notch as described previously for crescent fractures. The same procedural steps should be taken to safely place the tine onto the anterior surface of the lateral ala, namely simultaneous finger palpation to localize and avoid the sacral foramina and nerve roots. The outer tine is placed onto the outer table of the ilium (Fig. 46-86A–C). The clamp is then closed, thereby reducing the anterior aspect of the joint. Complete reduction of the SI joint is confirmed with AP, inlet, and outlet fluoroscopic views. Critical analysis of these views will reveal any persistent translational or rotational deformities, which if present, need to be corrected. 
Figure 46-85
 
Photograph demonstrating reduction of the SI joint with a pointed reduction forceps from the posterior approach utilizing inferior clamp placement.
Photograph demonstrating reduction of the SI joint with a pointed reduction forceps from the posterior approach utilizing inferior clamp placement.
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Figure 46-85
Photograph demonstrating reduction of the SI joint with a pointed reduction forceps from the posterior approach utilizing inferior clamp placement.
Photograph demonstrating reduction of the SI joint with a pointed reduction forceps from the posterior approach utilizing inferior clamp placement.
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Figure 46-86
 
Photographs demonstrating reduction of SI joint with a pelvic clamp placed through the greater sciatic notch onto anterior aspect of the ala from a posterior approach. A: Posterior view. B: Anterior view. C: Posterior view showing both clamps in place to insure anatomic reduction.
Photographs demonstrating reduction of SI joint with a pelvic clamp placed through the greater sciatic notch onto anterior aspect of the ala from a posterior approach. A: Posterior view. B: Anterior view. C: Posterior view showing both clamps in place to insure anatomic reduction.
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Figure 46-86
Photographs demonstrating reduction of SI joint with a pelvic clamp placed through the greater sciatic notch onto anterior aspect of the ala from a posterior approach. A: Posterior view. B: Anterior view. C: Posterior view showing both clamps in place to insure anatomic reduction.
Photographs demonstrating reduction of SI joint with a pelvic clamp placed through the greater sciatic notch onto anterior aspect of the ala from a posterior approach. A: Posterior view. B: Anterior view. C: Posterior view showing both clamps in place to insure anatomic reduction.
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If the reduction is satisfactory, rigid fixation of the SI joint should be accomplished with placement of one or two partially threaded SI screws to allow for compression and aid in reduction. The guide pin can be placed through the open wound, but generally because of the trajectory required due to the length of the guide pin, an additional stab wound is made on the skin through which the pin is introduced. However, direct visualization of the tip of the pin is possible and will allow for the pin to be placed at the appropriate starting point. This entry point is approximately two thirds of the way down from the PSIS and about 20 mm anterior to the crista glutea. It can also be found 20 mm posterior to the sciatic notch at its deepest point and 20 mm superior. Once the appropriate starting point has been confirmed with fluoroscopic imaging, the pin is advanced through the lateral ilium and across the SI joint into the S1 body all the way across, stopping short of the opposite SI joint. Fluoroscopy is performed throughout placement of the guide pin, rotating between the inlet and outlet views. The length of the screw is measured and then placed over the guide pin. A partially threaded screw with a washer is used to aid in compression and prevent penetration of the lateral ilium. A second screw can be placed if there is adequate space within the first body. Alternatively a screw can be placed at the S2 level. 
After fixation is complete, the wound should be irrigated and a drain placed underneath the gluteal muscles. The TGM and fascia are reattached to the iliac crests with heavy 0 Vicryl suture in a figure-of-eight interrupted fashion. The subcutaneous tissue and skin is closed. Staples can irritate the posterior skin and thus a subcuticular closure followed by use of Dermabond tape is used. A sterile dressing is applied. 
Postoperative Care.
Despite the approach used, the postoperative regimen is generally the same. The patient is kept nonweightbearing on the side of fixation for approximately 12 weeks. DVT prophylaxis is maintained for at least 6 weeks and is dependent on other associated injuries. Usually a drain is placed and removed at 48 hours and antibiotics are continued. Staples or sutures are removed at the 2-week point. 
Potential Pitfalls and Preventive Measures.
If approaching the SI joint anteriorly, inadvertent iatrogenic injury to the L5 nerve root can occur with excessive exposure medially onto the sacrum. It is imperative that the nerve root be identified and protected when clamp or screw placement is used for the reduction maneuvers mentioned to reduce the SI joint from the anterior. If a plate is being used to stabilize the SI joint, the L5 nerve root must be kept out of the way so that the nerve root does not lie underneath the plate’s medial edge. 
When approaching the SI joint posteriorly, prone positioning can cause posterior translation of the hemipelvis in relation to the sacrum. This occurs because the patient is resting directly on the ASIS. It is important to ensure that the pelvis is hanging freely to avoid this. In addition to posterior translation, resting on the ASIS will result in an external force on the ilium, which can hinder appropriate reduction maneuvers. 
In either approach, careful scrutiny of the reduction is needed. Palpation through the greater sciatic notch posteriorly or the anterior sacral articulation from the front can aid in evaluating the rotation and ensuring anatomic reduction. 
Treatment-Specific Outcomes.
In their series of pure SI joint dislocations, Mullis and Sagi217 evaluated functional outcomes in a group of surgically treated patients with a minimum of 1-year follow-up. All 23 patients had SF-36, SMFA, Iowa pelvic scores, and Majeed pelvic scores. They found that anatomic reduction of the SI joint was the only predictor of a favorable outcome. In addition, if SI joint ankylosis occurred, functional outcome was not affected. In a prospective study by Leighton and Waddell,174 42 patients had a formal ORIF of the sacroiliac joint from an anterior approach versus 12 cases of percutaneous SI screw fixation. There were only two minor nerve palsies. An anatomic reduction was achieved in 80% of the cases with 100% healing rate. There were no cases of postoperative displacement, despite an early mobilization plan. One other study found similar findings in a small group of patients, where 8 of 10 had anatomic reductions and an excellent outcome versus the remaining two that were nonanatomic with persistent pain and a fair outcome.308 This is in contrast to other studies where functional outcome did not necessarily correlate with anatomic reduction, but these studies included a wide variety of injury patterns and treatments.70,220,346 

Sacral Injuries

Percutaneous Iliosacral Screw Fixation.
Preoperative planning
Percutaneous iliosacral screw fixation can also be used for sacral fractures. It is especially useful to stabilize complete fractures that are nondisplaced. If the fracture is displaced or there is nerve root involvement, open reduction from a posterior approach is often required. Decompression of the nerve roots and/or removal of comminuted fragments in the foramen may be needed to prevent further injury once screw fixation is placed. Percutaneous screw fixation can still be performed afterward, but reduction is paramount. Unfortunately, the reduction can be difficult to obtain and even more difficult to judge because of the fracture comminution and plastic deformation of the sacral ala that often accompanies such fractures. In addition, because of the limited view provided by an intraoperative fluoroscopy image, the inlet, outlet, or AP views often cannot be visualized, which makes the evaluation of the reduction difficult. To aid in the evaluation of the reduction, the following subtle parameters can be evaluated: (a) The level of the iliac crests, acetabular domes, and ischial tuberosities are equal bilaterally; (b) the distance from the sacral spinous process to the PSIS is equal bilaterally; (c) ischial spine profile is the same bilaterally; and (d) the contour of the pelvic brim from the midline of the sacrum to the pubis is symmetric bilaterally. If there is any question, intraoperative plain radiographs can be obtained to view the entire pelvis. 
Positioning.
The position for placement of iliosacral screws for sacral fractures will depend on the need for other procedures associated with the overall injury pattern and associated neurologic deficits. In cases where there is complete fracture of the sacrum and intact neurologic examination where decompression of either nerve roots and or the L5 nerve root are not required, supine positioning will suffice. The patient may require traction, which can be done easily in this position. 
If the patient has compression of nerve roots or they are at risk for comminuted fractures with bony fragments, in cases of Zone II injuries, these fractures may need to be decompressed and reduced from the back. Thus, these injuries will require prone positioning to gain exposure at the sacrum and subsequent laminectomy and decompression with removal of bony fragments. The iliosacral screw is still placed in a percutaneous fashion as described previously and below. 
In cases where there is significant comminution of the sacral fracture, especially at the superior margin of the ala, and there is concern that the L5 nerve root may be or become entrapped in the fracture site or evidence of an L5 nerve root deficit, an anterior approach through the first window (lateral window) of the ilioinguinal approach is needed and will require supine positioning. This is done to “extract” the L5 nerve root from the fracture prior to reduction and stabilization. Placement of an iliosacral screw can then follow in the standard percutaneous fashion. 
Surgical Approaches.
The surgical exposures are mentioned previously. A percutaneous method with the starting point determined with a lateral sacral view can be utilized. The posterior approach is used if sacral exposure is needed for decompression. The lateral window is chosen for L5 extraction. 
Surgical Technique.
The surgical technique differs slightly from that used in the stabilization of SI joint dislocations. The principles of AO technique should be followed. The screw trajectory is directed perpendicular to the fracture plane to achieve optimal reduction and stability. This usually requires the screw be placed from lateral to medial and more parallel to the S1 endplate, on both the inlet and outlet, than what is desired in SI joint dislocations. In addition, the use of fully threaded screws has been recommended in cases of comminuted Zone II sacral fractures to prevent potential nerve root injury with excessive compression. Partially threaded screws can be used for Zone I or III injuries as well as noncomminuted Zone II fractures. Because of the potential instability in complete fractures of the sacrum, many authors have used a “transsacral” screw to gain additional fixation in the contralateral ilium.12,63,95 This technique also is useful in cases of bilateral sacral fractures and in osteopenic bone to enhance the fixation construct, especially with the use of locking nuts208 (Fig. 46-87). Because the placement of such a screw must be directed almost straight lateral to medial, the patient’s anatomy must be carefully studied. Evaluation of the CT scan preoperatively is necessary, and if available 3D reconstructions can be useful to better elucidate any abnormalities such as sacral dysmorphism, which can often be a contraindication to the placement of such a screw at the traditional S1 level. In those cases, however, the S2 level may be able to accommodate a transsacral screw. 
Figure 46-87
Radiograph of patient with bilateral sacral fractures treated with transsacral screw.
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The theoretical advantage to the transsacral screw is to provide improved resistance to any cephalad displacement because of the tip of the screw being in the opposite side of the pelvis due to the better purchase and additional compression that can occur. This rotation point occurs at the tip. The contralateral ala and the superior aspect of the S1 endplate help to buttress the screw and block any superior translation and rotation. Tornetta et al.345 looked at a cadaveric biomechanical study to evaluate a standard iliosacral screw with a transsacral screw versus a standard two-iliosacral screw construct. There was no improved performance with the transsacral screw, but the mode of failure was different. The long screw construct bent, whereas the standard screws cut out. There was better purchase with the transsacral screw. This suggested that the longer lever arm may be advantageous in the comminuted or nonanatomic situations.345 Sacral fractures can be adequately stabilized with one or two SI or transsacral screws with or without supplemental anterior fixation. This will maintain the reduction until healing has occurred. The benefit of the second screw has not been well documented in the literature.296,361 Most pelvic surgeons utilize a second screw if it can be placed safely into either S1 or S2 predominately in the displaced, unstable sacral fracture (Fig. 46-88A–D). 
Figure 46-88
Patient with unstable, complete right-sided sacral fracture.
 
A: Three-dimensional outlet view. B: Postoperative outlet radiograph with SI screws (S1,S2). C: Postoperative CT scan at S1 level showing safe placement. D: Postoperative CT scan at S2 level showing safe placement and comminution of sacral fracture.
A: Three-dimensional outlet view. B: Postoperative outlet radiograph with SI screws (S1,S2). C: Postoperative CT scan at S1 level showing safe placement. D: Postoperative CT scan at S2 level showing safe placement and comminution of sacral fracture.
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Figure 46-88
Patient with unstable, complete right-sided sacral fracture.
A: Three-dimensional outlet view. B: Postoperative outlet radiograph with SI screws (S1,S2). C: Postoperative CT scan at S1 level showing safe placement. D: Postoperative CT scan at S2 level showing safe placement and comminution of sacral fracture.
A: Three-dimensional outlet view. B: Postoperative outlet radiograph with SI screws (S1,S2). C: Postoperative CT scan at S1 level showing safe placement. D: Postoperative CT scan at S2 level showing safe placement and comminution of sacral fracture.
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Postoperative Care.
The patient is kept nonweightbearing on the side of iliosacral screw fixation. When injuries are bilateral, they are kept in a wheelchair with either total assist or transfers on the more stable side of injury. Patient factors may come into decision making such as obesity and bone quality. The percutaneous incisions are closed in a routine fashion. No drains are needed unless an open procedure for nerve root decompression is required, as outlined previously. Those procedures may need a drain, which is removed after 48 hours during which antibiotics are kept on board. 
Potential Pitfalls and Preventative Measures.
In addition to those mentioned under “percutaneous iliosacral screw” fixation, sacral fractures also require special care to avoid iatrogenic nerve injury when reducing fractures. Reduction of highly comminuted sacral fractures can be problematic. Careful preoperative scrutiny of the scan is required to ensure that bony fragments are not in the foramen. If so, decompression may be needed prior to reduction, so as not to cause inadvertent injury. In addition, overcompression with partially threaded screws in Zone II comminuted fractures theoretically have the potential to cause iatrogenic nerve root injury, although this has not been reported after acute treatment. Some surgeons use fully threaded screws to prevent this from occurring but accept the theoretical higher risk of nonunion. 
It is also imperative that fracture reduction occur prior to screw placement, as it has been well shown the increased neurologic and potential vascular injuries with a malreduced sacrum.260 

ORIF of Vertical Shear Fractures

Preoperative planning.
A thorough neurologic examination should be performed on patients with sacral fractures to ensure that no deficits exist. Careful evaluation of the preoperative imaging, primarily the CT scan, should look for nerve root compression by bony fragments in the case of comminuted Zone II sacral injuries as well as sacral canal occlusion. In addition, spinopelvic disassociation should be ruled out. Associated soft tissue injuries such as Morel-Lavallee lesions can complicate surgical exposure and may need to be addressed first with incision, irrigation, debridement, and closure over drains.283 
Consideration for placement of an inferior vena cava (IVC) filter should be discussed with the trauma surgeons prior to manipulation of the pelvis due to concerns about clot dislodgement. This is especially true in cases where immediate postinjury chemoprophylaxis is contraindicated, such as with head injuries or splenic and hepatic lacerations. If placed, removable filters are favored, as they can be removed in about 6 months on an outpatient basis. 
Positioning.
The patient is placed prone on rolled blankets placed in the longitudinal direction and on a radiolucent table taking care to pad all bony prominences. The pelvis should hang freely distal to the rolls such that the rolls do not exert a force on the unstable pelvis, which could deter fracture reduction. The posterior pelvis and much of the lower lumbar area should be draped into the surgical field to allow for adequate access. This should include the lateral margins of the flank and the buttocks all the way down to the table to allow exposure for iliosacral screw fixation if needed. 
Often longitudinal traction is needed to aid in the reduction (see Fig. 46-35A, B). The opposite, uninjured side can be left free while the injured side is placed in skeletal or boot traction. The problem is that there is no post for resistance unless the procedure is done using a perineal post. However, the pelvis can still rotate around the post as traction is applied. Some have advocated the use of skeletal stabilization of the uninjured pelvis to either a frame172 or the table191 in order to provide counter traction and stabilization against which traction can be applied to the injured side. 
Surgical Approaches.
A paramedian approach can be performed as previously described for reduction of the sacral fracture and decompression of the nerve roots. If triangular osteosynthesis is required, a midline approach from L4 to S3 is made. The thoracolumbar fascia is dissected approximately 2 to 2.5 cm lateral to the transverse processes. The intermuscular plane between the erector spinae muscles and the multifidus is developed, which will lead directly down to the L4-L5 facet joint and the PSIS. The paraspinal muscles are then elevated off the dorsum of the sacrum and reflected medially; this will expose the sacral fracture and foramina. The posterior SI ligaments should not be detached. Nerve decompression can be performed if indicated, either through removal of bony fragments within the foramen or a midline sacral laminectomy. Implantation of the hardware can proceed as indicated below. 
Surgical Technique.
Open reduction and internal fixation of sacral fractures is warranted instead of solely SI screw fixation in cases of severe comminution, osteoporotic bone, or disruption of the L5-S1 facet joint, due to the higher failure rate in some series115,247,296 (Fig. 46-89A, B). Either plating or spinal-pelvic constructs can be used to stabilize such fractures. Plating involves the use of 2.7 mm or 3.5 mm reconstruction plates (locking or nonlocking) placed lateral to the foramen and pedicles. Bicortical fixation is preferred. Plate application requires much more soft tissue dissection and screw purchase can be problematic. An alternative method of triangular osteosynthesis has been used and can also augment SI screw fixation for these fractures.283 The tenet behind this technique is to bypass the sacral fracture with fixation to the ilium such that the force transmission travels from the ilium up to the spine without stress on the sacrum itself. These constructs are also known as lumbopelvic fixation or triangular osteosynthesis. Kach and Trentz145 originally described this method and found this technique to be both biomechanically295 and clinically superior to SI screws alone in maintaining reduction in comminuted sacral fractures.286,294 Treatment often requires specialized spinopelvic fixation234,283,293 and should be undertaken by someone who is proficient in both pelvic and spinal instrumentation. 
Figure 46-89
 
A: Two-week follow-up outlet radiograph showing early posterior failure with bending of screw of patient with vertical shear fracture (same patient as in Figures 46-25 and 46-35). B: Three-month follow-up outlet radiograph showing healing without much change in failure.
A: Two-week follow-up outlet radiograph showing early posterior failure with bending of screw of patient with vertical shear fracture (same patient as in Figures 46-25 and 46-35). B: Three-month follow-up outlet radiograph showing healing without much change in failure.
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Figure 46-89
A: Two-week follow-up outlet radiograph showing early posterior failure with bending of screw of patient with vertical shear fracture (same patient as in Figures 46-25 and 46-35). B: Three-month follow-up outlet radiograph showing healing without much change in failure.
A: Two-week follow-up outlet radiograph showing early posterior failure with bending of screw of patient with vertical shear fracture (same patient as in Figures 46-25 and 46-35). B: Three-month follow-up outlet radiograph showing healing without much change in failure.
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Fixation points in the spine need to be determined and can vary anywhere from the L4 to the S1 pedicle based on the injury pattern. The usual point of spinal fixation is the L5 pedicle. However, often the l% transverse process has been disrupted, which may extend into the whole or part of the L5 pedicle, preventing fixation. In those cases the L4 pedicle can be chosen. In some instances the S1 pedicle can be utilized for the spinal point of fixation if the involvement of both the posterior and lateral aspects of the sacrum is minimal and with little comminution. 
When exposing the fracture, care should be taken to avoid disrupting the facet joint capsules, as this may lead to joint degeneration and low back pain. The L5 pedicle is found just lateral to the L4-L5 facet joint with the entry point at the junction of the transverse process and the lateral wall of the facet. The pedicle screw should be placed under fluoroscopic visualization utilizing AP, lateral, and oblique views. It is important to remember that the procedure should be performed with someone proficient in spinal instrumentation. 
At this point the screw for iliac fixation is placed. The entry point is just distal to the PSIS. Because the fixation can be prominent here and recessing the screw under the posterior aspect of the crest in a cleft between the ilium and sacrum. The posterior SI ligaments should not be taken down as this can affect stability.283,294 When placing the screw, the outer cortex should be perforated with a 3.5 mm drill bit and the medullary canal between the inner and outer tables entered. The usual placement is at about 10 to 20 degrees off the vertical in a line aimed at the AIIS, or alternatively the greater trochanter as an external reference point. The preoperative CT axial images can aid in determining this trajectory. It is essentially a “posterior to anterior” AIIS pin or LC II screw from the PSIS toward the AIIS. It should lie above the sciatic buttress (visualized on the iliac oblique view) and centered in the teardrop (visualized on the obturator oblique view). After opening the cortex and ensuring that one is between the two tables, it is often best to allow the screw to find its path. Care should be taken to ensure that it does not go into the greater sciatic notch inferiorly or into the SI joint medially. 
The two points of fixation can be connected to one another utilizing a 5-mm rod and screw to rod clamps. Keep in mind that the reduction must be obtained first. The SI screw is then placed in the method previously described to close any fracture gap, followed by locking of the pedicle screw rod clamps. At this point no further manipulation of the fracture can occur. Prior to placement of the SI screw, sacral nerve root decompression may be indicated in these vertical sacral fractures. The indications are similar to those described before for Zone II injuries: (a) Neurologic findings in the form of a radiculopathy with CT scan demonstration of an offending bony fragment(s) in the foramen; and (b) the neurologically intact individual also with CT scan demonstration of a bony fragment(s) in the foramen, which may injure or compress the nerve root with manipulation and reduction maneuvers. The decompression is performed through the fracture site itself without the need for laminectomy. A lamina spreader can be placed into the fracture site. The hematoma can be removed for exposure of the sacral nerve roots and the bony fragment(s). A pituitary rongeur can then gently extract the fragment(s) from the foramen. Bilateral cases are often the lumbopelvic dissociative patterns as discussed below, and these require bilateral lumbopelvic fixation constructs with or without SI screws. 
These constructs result in improved stability maintaining the reduction and with lower rates of hardware failure. The biomechanical superior construct also allows for earlier weightbearing.283,286,294 This technique is not without problems or complications. It is a technically demanding procedure not often performed by many orthopaedic pelvic surgeons. The technical aspects of the procedure should be reviewed. Assistance by someone facile in pedicle screw placement should be obtained. The most common problems include (a) prominent and symptomatic fixation, (b) delayed union and nonunion, and (c) lumbosacral scoliosis. Many of these issues can be avoided if careful attention is paid during reduction and implantation. 
Postoperative Care.
The patients are kept nonweightbearing on the side(s) of injury and relying on crutches or a walker, or a wheel chair in the case of bilateral injuries, for 3 months. Some advocate immediate partial weightbearing, followed by full weight bearing at the 6-week mark.283 The decision should be made based on patient factors and the surgeon’s experience. In either case, the patient should be mobilized on postoperative day one with physical therapy. Drains should be placed if excessive bleeding occurs and maintained for 48 hours, assuming the output has decreased sufficiently to warrant removal. The patient should be kept on antibiotics while the drain is retained. Patients should be placed on DVT prophylaxis, Thromboembolic Deterrent (TED) hose, and sequential compression devices (SCDs) while an inpatient. Chemoprophylaxis should also be started and maintained for at least 6 weeks or longer depending on the patient’s mobility status. The duration is anecdotal and no clear evidence exists for a standard of care. CT scans at 6 months postoperatively have been recommended to determine fracture healing. If it is healed, hardware removal is recommended for the spinal pelvic constructs usually in 6 to 9 months.283,286 
Potential Pitfalls and Preventive Measures.
Anatomic reduction is ideal in the management of these fractures. Internal or external rotation deformities can be corrected by rotating the injured leg. Any residual cephalad or lateral displacement can be reduced by placing the tines of a pointed reduction clamp (Weber) onto the PSIS and sacral spinous process. If the displacement is in the AP plane, manual manipulation of the fracture by using a threaded Schanz pin in the PSIS or PIIS and manually moving the hemipelvis in the appropriate direction will allow reduction. This should be done prior to closing the fracture gap so that the hemipelvis can be easily manipulated. Using this same Schanz pin as a “joystick” will allow correction of any residual internal or external rotation by rotating the hemipelvis in the desired direction, if manipulation of the lower extremity fails. 
Indirect reduction should not be performed by distraction of the spinopelvic rod due to the axis of the rod being posterior and lateral.283 This can result in gapping of the fracture and an increase in nonunion formation. This can also lead to lumbosacral scoliosis. Any fine-tuning of the reduction should be performed with traction and reduction clamps or the Schanz screws. The iliosacral screw can be placed to hold the reduction once it is obtained. The spinopelvic construct can then be locked down around the iliosacral screws to neutralize the forces. 
Treatment-Specific Outcomes.
Triangular osteosynthesis for unstable vertical shear sacral fractures has been proven to be reliable. Sagi et al.286 looked at their results in a prospective cohort of 40 patients with one year follow-up. They found that the procedure allowed for early weightbearing at 6 weeks without loss of reduction. Although operative reduction was maintained in 95% of patients until healing, there was concern over a high rate of technical problems and complications. All patients developed asymmetric tilting at the L5 level with L5-S1 facet joint distraction necessitating hardware removal in all patients. There was a 13% incidence of iatrogenic nerve injury. All patients had lower outcome scores at one year than the population mean. However, 93% had returned to either work or schooling at one year compared to only 10% at 6 months.286 
In a prospective study by Hu et al.,134 22 patients were treated for their vertically unstable sacral fracture with triangular osteosynthesis. There were 16 unilateral injuries all treated with unilateral fixation and 6 bilateral injuries, 50% treated with bilateral fixation. There was a 100% union rate by 6 months, no loosening or hardware failure, no iatrogenic nerve injuries, and 82% return to work. Functional outcomes, according to the Majeed score, were 86% good to excellent results. They also found that this fixation construct allowed for early weightbearing. 

Lumbopelvic Fixation for Spinopelvic Disassociation

Preoperative planning.
An extension of the vertical shear sacral fracture is the spinopelvic dissociation, which is essentially a sacral fracture dislocation. The term “spinopelvic dissociation” was described to delineate this fracture pattern from a bilateral sacroiliac joint dislocation or the lumbosacral fracture dislocation.14,365 These tend to occur through the vestigial disc space resulting in kyphosis. The cephalad segment translates posteriorly.282,333 These fractures are often overlooked on the standard pelvic radiographs as well as on the axial CT scans (Figs. 46-90 and 46-17A). A lateral sacral radiograph may aid identification. These injuries should be suspect if the plain radiographs show bilateral transforaminal sacral fractures, L5 transverse process fractures, or abnormalities of the superior sacral foraminal outlines. With significant kyphosis present, the upper sacrum will appear as if viewing an inlet view on the standard AP. Some have also described the “stepladder sign,” which is indicative of anterior foraminal disruption.224,293,354 The CT sagittal reformations are the key to the diagnosis (Fig. 46-17B). Three-dimensional reconstructions can aid in surgical preparation and planning (Fig. 46-17C). MRI can be useful to evaluate the neurologic injury by defining the sites of neural compression.375 
Figure 46-90
Innocuous-looking AP radiograph of patient with lumbopelvic disassociation (same patient as in Figure 46-17).
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Despite the unstable nature of these injuries, the pelvic ring tends to be stable, since the SI joints and distal sacrum are intact. They result instead in spinal instability and subsequently these injuries are often associated with neurologic deficits. Some studies have indicated 100% involvement with bowel and bladder dysfunction and loss of anal sphincter tone.13,293 Most often they affect the inferior sacral nerve roots causing a cauda equina syndrome. These patients have impaired bladder function, decreased rectal tone, and saddle anesthesia. Due to the high energy nature of such injuries, many patients have associated injuries that may preclude appropriate neurologic evaluation upon admission, delay surgical intervention, or complicate the overall neurologic picture.338 A detailed and thorough physical examination is warranted preoperatively. This can be difficult to obtain, since many patients are multiply injured and may be intubated. All patients should undergo initial stabilization and treatment of associated injuries per ATLS protocol. Secondary surveys should be focused on the neurologic function in cases with spinopelvic dissociation and other spinal injuries. The following specifics should be checked in addition to a general neurologic examination: Spontaneous and voluntary rectal sphincter contraction, perianal sensation (light touch and pinprick), and ankle dorsiflexion (L5 nerve root). Keep in mind that these patients may have a higher spinal injury, which may confuse the neurologic picture. 
Traditionally many of these injuries were treated nonoperatively due to surgical inability to obtain and maintain reductions. Nonoperative management in the neurologic intact patient has included bed rest with either skeletal traction or external cast/orthosis immobilization, followed by early mobilization. Unfortunately, many patients have neurologic compromise and instability and can develop a painful deformity or worsening of their neurologic function. As stabilization techniques have improved, it is clear that if the patients’ condition permits, these injuries are best treated surgically and by an experienced spinal surgeon. In cases of an impacted and stable pattern without significant kyphosis or neurologic deficit, some trauma surgeons have advocated bilateral SI screw fixation alone,224 but this has been controversial. Other techniques to stabilize these injuries have included transiliac rod fixation or plating1 or transsacral plate fixation. Many feel that these injuries require reduction, decompression, and bilateral posterior lumbopelvic fixation to control or prevent further kyphotic deformity and allow early mobilization of the patient.293 The lumbopelvic fixation has also been combined with transsacral plate fixation or iliosacral screw fixation.114 Most have now advocated lumbopelvic fixation with rod-screw constructs with or without iliosacral screws for fixation and laminectomy as needed for neurologic decompression.375 
Positioning.
If the injury can be treated with percutaneous stabilization in the case of select fractures,224 the procedure can be done either prone or supine. For formal open reduction and stabilization, the patient is placed prone on rolled blankets placed in the longitudinal direction and on a radiolucent table, taking care to pad all bony prominences. The pelvis should hang freely distal to the rolls such that the rolls do not exert a force on the unstable pelvis, which could deter fracture reduction. The posterior pelvis and much of the lower lumbar area should be draped into the surgical field to allow for adequate access. This should include the lateral margins of the flank and the buttocks all the way down to the table to allow exposure for iliosacral screw fixation if needed. Because of the instability and bilateral nature of these injuries, both lower extremities can be placed in longitudinal traction utilizing a perineal post. In cases where bony fragments may pose a risk to the nerve roots, care should be exercised when doing this so as to not cause iatrogenic injury. Otherwise iliac and pedicle screws293 or a distractor between L5 and the ilium can be used intraoperatively to aid in the reduction.375 A spine table can be used if either traction or iliosacral screw fixation is not required as an adjunct. 
Surgical Approaches.
For lumbopelvic fixation, a midline approach from L4 to S3 is made. The thoracolumbar fascia is dissected approximately 2 to 2.5 cm lateral to the transverse processes. The intermuscular plane between the erector spinae muscles and the multifidus is developed, which will lead directly down to the L4-L5 facet joint and the PSIS. The paraspinal muscles are then elevated off the dorsum of the sacrum and reflected medially; this will expose the sacral fracture and foramina. The posterior SI ligaments should not be detached. Nerve decompression can be performed if indicated, either through removal of bony fragments within the foramen or a midline sacral laminectomy. Early decompression has been advocated with neurologic compromise to prevent further injury and it is hoped to maximize chance of recovery.293 Even in the absence of a neurologic deficit but in the presence of bony fragments in the canal or foramen, laminectomy to remove these fragments has been recommended to prevent iatrogenic injury with reduction.375 
Surgical Technique.
Once the exposure has been performed, the injury can be addressed. In any fracture case, the reduction must be obtained and then maintained with fixation constructs. For patients presenting with neurologic deficits or who are at risk for injury due to bony fragments, decompression via sacral laminectomy is done prior to reduction. However in some cases, reduction may or may not be required. When the fracture is impacted and insignificant kyphosis present, in situ stabilization may be all that is needed with iliosacral screws.224 The determination to treat these with percutaneous stabilization requires careful scrutiny of the preoperative imaging studies and a careful neurologic examination of the patient. In cases of excessive kyphosis and sacral inclination, the spinal pelvic construct can be placed first followed by reduction. The fracture is disimpacted by distracting across the rods and allowing the reduction to occur. Positioning of the patient by hyperextending the lumbosacral spine, pelvis, and hips can help correct the kyphosis. Intraoperatively, an osteotome carefully placed through the fracture line to the front of the sacrum can act as a lever. Once the reduction is obtained, it can be maintained by locking the spinal pelvic construct into position. Iliosacral screws are not needed. If there is concern with the integrity of the L5-S1 facet joints, some have advocated fusion from L5 to the sacrum.293 
It is important to restore the sagittal alignment of the spine to the sacrum. Coronal plane alignment can easily be viewed intraoperatively and confirmed with fluoroscopic imaging; sagittal alignment is much more difficult.375 Fluoroscopy of the lateral view should be used to assess the alignment preoperatively when positioning the patient. This will act as a reference to compare to after reduction but prior to fixation.365 A radiologic parameter, termed the pelvic incidence, initially described for sagittal curve balance173 was utilized as a way to assess the adequacy of sagittal plane reduction in H-type spinopelvic dissociations.126 
The surgical exposure and technique for triangular osteosynthesis is described in the previous section. The lumbopelvic construct is done similarly but with bilateral fixation. Pedicle screws are placed on each side at the L5 level (again depending on the involvement of the pedicle itself). Alternatively, fixation may be needed at the L4 level. The iliac screws are placed bilaterally with recession into the bony prominence of the PSIS. These are usually placed parallel to the SI joints and directed in posterior to anterior fashion toward the AIIS.293 An iliac oblique view and/or a true lateral of the pelvis can be helpful to ensure safe placement and that it does not penetrate the greater sciatic notch. The obturator outlet oblique view combined with the obturator-inlet view can aid in confirmation of the starting point and final screw position.283,293 Rods are bent appropriately and attached from the pedicle screw to the iliac screw and left loose. Reduction is obtained and then maintained by locking down the rods to the screws. Cross connector rods are placed to join the two sides.293 Distraction along the spinopelvic rod to aid in reduction should not be performed, as this has been shown to increase the fracture gap and resultant lumbosacral scoliosis, and may cause asymmetric overloading of the facet joints.283 Additional fixation with iliosacral screws may be considered depending on the fracture pattern and whether they will add anything to the overall construct, reduction, or stabilization of the fracture. The need for a posterolateral arthrodesis is controversial and should be decided on a case-by-case basis. If the patient has an injury to the L5-S1 interval or involvement of the facet joints, fusion has been recommended.142 If fusion is performed, the facet joints, lumbar transverse processes, and the sacral ala should be decorticated. The morselized laminectomized bone, autograft from the PSIS, or allograft chips can be used as bone graft. If fusion is not performed, some recommend hardware removal after fracture healing. 
Postoperative Care.
The technique of lumbopelvic fixation for these injuries has allowed for early mobilization, and in cases without associated lower extremity injuries, early partial to full weightbearing13,114,151,293,294 depending on other patient-associated factors (obesity, bone quality). Therefore, postoperative weightbearing must be customized to the individual patient. Drains can be placed if there is concern with hematoma formation. 
Potential Pitfalls and Preventive Measures.
The most commonly reported complications after spinopelvic fixation include wound complications, hardware irritation, and incomplete neurologic recovery. In addition, technical errors in placement of the pedicle screws and inadequate reduction can occur. To prevent such errors, the spinopelvic construct should be locked down after reduction and compression of the sacral fracture. Although nonunions are rare in sacral fracture, leaving gaps will significantly increase the likelihood of one occurring. The clamps and the screws should be used to close the fracture gap under c-arm fluoroscopy so as not to overcompress. If the fracture cannot be reduced, check to ensure that adequate longitudinal traction is being applied. A perineal post may prevent caudal translation of the hemipelvis as well. Wound dehiscence should be treated early and aggressively. In cases of new neurologic deficits, a new CT scan should be ordered. Evaluation of the sacral foramina and loose bony fragments should be sought and potential L5 nerve root entrapment into the fracture site at the top of ala. To prevent entrapment, careful preoperative evaluation of the sacral ala and the position of the L5 nerve root in relation to any comminution should be undertaken. 
Treatment-Specific Outcomes.
Outcomes in the treatment of spinopelvic dissociation are hard to interpret because of the complex and multiple injuries that many of the patients have sustained. Although no comparative studies between nonoperative and operative studies have been published, it has become clear in the recent literature that operative intervention is indicated and has relatively good union rates. Published series are limited and comprise small subsets of patients with various treatments, associated injuries, and thus variable outcomes. The neurologic deficits and associated injuries that occur with the fracture tend to dictate the outcome, as opposed to the sacral fracture. It has been reported that improvement in the neurologic outcome occurs in up to 80% irrespective of whether operative intervention is performed. This is especially true in cases of incomplete neurologic deficits, where 86% of patients with bowel and bladder dysfunction but intact nerve roots had complete recovery. If one sacral nerve root was transected, only 36% had recovery of function.293 In cases of bilateral transection or avulsion of nerve roots, there is minimal chance of recovery.354 
The actual surgical procedure itself is successful in maintaining the fracture reduction and healing. The technique of lumbopelvic fixation is amenable to early mobilization and weightbearing barring other issues. Schildhauer et al. 292 reported 100% union rate without loss of reduction with improvement of sacral kyphosis with this protocol. Although controversial, iliosacral screw fixation alone in fairly well-aligned noncomminuted fractures healed, without loss of reduction.224 Gribnau et al.114 retrospectively reviewed their small experience (8 patients) in the treatment of such injuries with a myriad of treatment options based on the fracture pattern, associated spinal injuries, and the surgeon’s experience. They all healed without loss of reduction. Complications were common, with 37.5% wound infection and a 37.5% need for hardware removal. All patients had mobility problems long term, but were not confined to bed. There was a high preponderance of depression and anxiety (50%). They felt that outcomes were difficult to assess due to the heterogeneity in fixation constructs as well as associated injuries and psychiatric issues. 
Tan et al.338 recently reported their results in a group of nine patients all treated with lumbopelvic fixation. All fractures went on to union without loss of reduction and hardware failure. Patients were evaluated with the Majeed score. They had 89% fair or better results with a mean score of 73.4 points. Seven patients had neurologic deficit, four with complete cauda equina and three were incomplete. Laminectomy and decompression was performed in all patients who had spinal canal compromise. Partial or full recovery was noted in 83% of those patients. Wound infection and hardware irritation occurred. 
A retrospective review of 15 patients treated over 8 years was published recently.142 The authors reported that patients had long-term dysfunction based on SMFA scores despite bother and daily activity subscores improving over time. All patients were treated with lumbopelvic fixation and six required supplemental anterior fixation for anterior instability. All but one healed and was attributable to loss of fixation due to a technical error. Ten patients had arthrodesis due to involvement of the L5-S1 level. Neurologic dysfunction was persistent in seven patients (100% with neurologic injury). Eleven of fifteen were able to return to their previous work. Wound complications, hardware irritation, and hematoma were noted. 
Postoperative Care of Pelvic Ring Injuries.
Drains and Soft Tissues
The majority of open procedures in pelvic ring fracture fixation will use a medium (15 Fr) round or flat Blake drain. It is discontinued when drainage is, 25 mL per 8-hour shift. Sutures or staples are left in place for at least 2 weeks. Many of these patients may already have or develop an ileus postoperatively, perhaps requiring a nasogastric tube. In addition, dietary intake should be advanced carefully and only when flatus and bowel sounds have returned. The use of narcotics postoperatively, necessary for pain control, can exacerbate the situation. Patients may have constipation. An aggressive postoperative bowel regimen with stool softeners is often necessary. 
Patients that sustain pelvic ring fractures, especially those associated with motor vehicle pedestrian accidents, equestrian accidents, or crush injuries may have associated internal degloving soft tissue injuries. These Morel-Lavallee lesions may complicate the treatment of these pelvic ring fractures, especially if open reduction is required (Fig. 46-91). It is clear that such soft tissue injuries can increase the rate of wound and soft tissue complications. These injuries often require surgical intervention, but the actual management has not been well established. A thorough incisional drainage, debridement, and irrigation of the wound can help prevent a potential infection. The dead space that has developed can be managed with negative pressure wound therapy to assist in closure as well as in getting the wound ready should formal ORIF be required.165 Successful management of the internal degloving can also be performed with percutaneous drainage and irrigation of the space.125,351 Concern over open incisional drainage occurs from the fact that the degloved skin and fat receive their entire blood flow from collaterals in the adjacent peripheral skin. The underlying fascia no longer is providing blood flow. Thus if the lesion is large enough, complete full-thickness necrosis with resultant skin sloughing has been known to occur. This may lead to exposed bone and fixation, which then necessitates debridement and subsequent flap coverage. No clear guidelines exist in the literature, and surgeons must rely on their experience or a seasoned orthopaedic traumatologist to appropriately manage the timing for fixation of the fracture. Early involvement by a plastic surgeon can also help improve the outcome in these complicated wounds. 
Figure 46-91
 
(A) Preoperative and (B) intraoperative photograph demonstrating fluctuance, ecchymosis, and degloving cavity with a large Morel-Lavallee lesion.
(A) Preoperative and (B) intraoperative photograph demonstrating fluctuance, ecchymosis, and degloving cavity with a large Morel-Lavallee lesion.
View Original | Slide (.ppt)
Figure 46-91
(A) Preoperative and (B) intraoperative photograph demonstrating fluctuance, ecchymosis, and degloving cavity with a large Morel-Lavallee lesion.
(A) Preoperative and (B) intraoperative photograph demonstrating fluctuance, ecchymosis, and degloving cavity with a large Morel-Lavallee lesion.
View Original | Slide (.ppt)
X
Mobilization and Weightbearing
Many of these patients are multiply injured, and as such the associated lower extremity injuries will dictate weightbearing and their other nonorthopaedic injuries will dictate mobilization, for example, head, thoracic (rib fractures), or abdominal injuries. If these other factors do not prevent mobilization, patients should be mobilized to a chair the day following surgery, and begin gait training with physical therapy the next day. Early mobilization helps with both pulmonary toilet and bowel/bladder function. In general, pelvic ring injuries with complete disruption of the posterior ring should be mobilized with nonweightbearing or touchdown weight earing for 12 weeks followed by progressive weightbearing as tolerated. Patient factors such as obesity, bone quality, as well as fixation construct and stability should be considered when determining weightbearing status. Stable and incomplete pelvic ring disruptions, stable impacted lateral compression injuries, or APC I injuries can usually be allowed full weightbearing immediately. However, careful repeat radiographic imaging should be performed after initial mobilization to ensure that occult instability was not missed. 
Many patients will dictate their own weightbearing based on their comfort level. Patients with stable impacted sacral fractures are able to move and roll easily while in bed. They often can weight bear immediately with minimal discomfort. On the other hand, patients who complain of significant pain and are unable to even log roll in bed tend to have an unstable pattern. These individuals may require further evaluation with fluoroscopic stress views under anesthesia and fixation if indicated. 

Management of Expected Adverse Outcomes and Unexpected Complications

Pelvic ring fractures can be life-threatening injuries. Treatment can be as simple as observation in the minimally displaced pelvic ring injury, or require significant surgical intervention. Complications can occur from both the injury itself as well as during treatment. These complications may involve neurologic, vascular, or visceral structures at the time of injury. Unfortunately these complications occur when the pelvic ring fracture is sustained, and management of the associated injuries is as crucial as the pelvic ring fracture management itself. Pelvic ring fracture surgery can be associated with complications and surgeons may face certain hurdles during the operative procedures. Orthopaedic traumatologists comfortable with pelvic ring fracture surgery should perform these procedures. Despite the experience of the surgeon, surgery for pelvic ring fracture reduction and fixation can be associated with large blood losses, hypotension, and prolonged operative times. In addition, intraoperative difficulties can arise from poor bone quality or severe fracture comminution. Postoperatively, wound dehiscence, infection, neurologic compromise, pin tract issues, and DVT, all too commonly, have to be addressed. Obesity has been shown to increase the complication rate almost 7 times and reoperation rate close to 5 times.297 It is important to understand the potential problems that may arise in the treatment of pelvic ring injuries and how to deal with them. 

Intraoperative Hemorrhage

Severe bleeding can accompany many pelvic ring fractures as discussed previously. It is imperative to understand the vascular anatomy surrounding the bony anatomy, as injury to some of the vascular structures can occur intraoperatively, thereby adding to the overall blood loss. Bleeding can be potentially life-threatening and must be dealt with quickly. The superior gluteal artery is at risk for injury during fracture reduction as well as stabilization, most notably with placement of an iliosacral screw.50 In the event that this should occur, direct control of the vessel is difficult, if not impossible. Therefore, the wound should be packed in an attempt to tamponade the bleeding and the patient taken directly to the angiography suite to undergo embolization. 
The corona mortis, a retropubic anastomosis between the obturator system and the external iliac or inferior epigastric systems, is at risk during anterior pelvic exposures.339,347 Although, the risk is more pronounced in acetabular surgery, any dissection around the anterior ring involving the rami can injure the vessels, resulting in excessive and rapid blood loss in a short time. When excessive lateral exposure is needed for reduction and/or fixation, the corona should be identified and ligated. In cases where inadvertent injury has occurred and hemostasis is difficult, embolization should be considered. 
Pelvic packing in the setting of damage control has been discussed previously. Venous bleeding is another significant source of bleeding at the time of injury. Although direct additional injury to these structures during fracture stabilization is rare, the venous system can continue to ooze during the operative procedure. The patient’s physiologic status should be continually monitored, since patients who have coagulopathy, hypothermia, or massive transfusions can lose a significant amount of blood in a short time. Constant communication between the anesthesiologist and the orthopaedic trauma surgeon with regard to the patient’s blood loss, urine output, blood gas results, body temperature, and overall physiologic status is crucial. It is easy to get distracted by the fracture reduction and stabilization and lose sight of the patient’s blood loss. 
Regardless of the etiology of intraoperative hemorrhage, in cases where the patient’s physiologic status deteriorates prior to completion of the surgical procedure, wounds should be packed or closed if possible. The patient should be taken to either angiography (arterial sources) or the intensive care unit (venous) for resuscitation and stabilization. The patient can be brought back to the operating room to complete the procedure once the patient’s condition has improved. 

Inability to Achieve Adequate Fixation

As our population ages, it is more frequent that geriatric patients are sustaining pelvic ring injuries, not only from low-energy falls, but from high-energy mechanisms as well. Many of these patients have extremely poor bone quality due to the pre-existing osteoporosis. Too often achieving adequate fixation is problematic and even more so frustrating, especially when a difficult reduction was finally obtained only to have it come apart because it cannot be maintained. Surgeons have created unique solutions to deal with such problems, and these are often based on past experience, as there are no clear guidelines or much in the way of current literature to guide decisions. Careful preoperative planning is necessary so as to anticipate potential problems with fixation. Patients with osteoporotic pelvic ring injuries may benefit from nonoperative treatment (if the fracture reduction is acceptable) or percutaneous procedures if there is concern for plate-screw fixation.359 
Locked plating has been a savior to the orthopaedic traumatologist in dealing with osteoporotic fractures in a multitude of anatomic areas, and the pelvis is no exception. In cases of poor anterior pelvic fixation, where there is osteoporosis or extensive comminution, locked plate-screw constructs have been extremely valuable. Anterior fixation can also be augmented by placing an additional plate perpendicular to the first or with a supplemental anterior pelvic external fixator.359 Keep in mind that percutaneous fixation may be preferred and be less problematic for these elderly patients who may require anterior external fixation.359 
Poor sacral bone quality secondary to osteoporosis can complicate posterior pelvic fixation. Supplemental fixation techniques may be required to enhance the stability of the construct such as multiple SI screw placement.204 Placement of the iliosacral screw into the contralateral ilium—the transsacral screw—has been described as a way to improve purchase of an otherwise inadequate iliosacral screw.12 Transiliac bars and plates can supplement poor posterior pelvic ring fixation.112 Various spinal pelvic constructs have also been shown to be biomechanically superior than other traditional techniques and can be employed in cases of fracture comminution if sacral anatomy precludes multiple SI screw placement, and in osteoporosis.15,295 

Loss of Fixation and Reduction

Close and careful follow-up of both operatively and nonoperatively treated patients for their pelvic ring injury should be undertaken. Patients treated nonoperatively should undergo serial radiographs after mobilization (nonweightbearing on side of injury) to ensure that the pelvic ring fracture pattern is stable. Patients with operatively treated fractures should undergo repeat radiographs after mobilization and at their 2-week follow-up to ensure that loss of fixation and reduction has not occurred. Obesity has been found to be a risk factor for the need for reoperation due to loss of fixation, and these patients should be monitored closely.297 Patients with vertical shear injuries and other grossly unstable patterns are at increased risk of malunion due to the severity of the trauma they sustained.146 A delay in diagnosis can lead to a pelvic malunion, which can be an extremely debilitating problem for the patient.188 The pelvic obliquity, internal rotation, and adduction deformities can cause significant problems.188 In a review of the literature on pelvic malunions and nonunions, studies report sitting imbalance or discomfort, gait abnormalities, dyspareunia, leg length discrepancy, and a 97% incidence of pain.146 Although the majority of pelvic malunions were found to be secondary to a nonoperative approach, use of external fixation as definitive treatment, or an inadequate initial reduction and stabilization,146 and prompt attention to early loss of reduction can help prevent late deformity and the subsequent disability associated with a pelvic malunion. 

Postoperative Wound Infection and Dehiscence

Wound infections after surgical intervention for pelvic ring injuries can occur, complicating the management of such injuries. Any infection and/or wound dehiscence should be dealt with expeditiously to avoid deeper pelvic infection and potential osteomyelitis. Percutaneous pelvic surgery rarely has issues with infection. There are patient factors that may increase risk of infections after pelvic surgery. In a multicenter study of operatively treated pelvic ring fractures, it was clear that obesity was a major risk for the development of infections after surgery.297 
Acute infection occurring within the early postoperative period (within 3 weeks) can often be treated with incision, debridement, and irrigation with retention of the hardware. Wound dehiscence has been commonly associated with posterior approaches, with infection rates reported up to 16%.331 Patients may have erythema, fever, elevated white blood cell count, and prolonged drainage. Early surgical intervention should be the norm to prevent deeper infection and risk of osteomyelitis. Subsequent need for serial debridements prior to closure should be based on intraoperative findings. Negative pressure wound therapy can be useful in wounds that may not be ready for closure immediately or that cannot be closed due to associated skin necrosis. Patients should be given intravenous antibiotics based on cultured organisms and sensitivities. Treatment up to 6 weeks or more may be required and should depend on multiple factors including the involvement of hardware. Hardware retention is ideal if possible. However, if hardware is involved and/or loose, revision fixation may be needed and may require staging if possible. Hardware removal followed by serial debridement and the revision in a clean wound should occur. Unfortunately in many cases this may require temporary external fixation to stabilize the pelvis while the hardware is out. However, revision at the time of debridement has been successful in a small series of patients.331 Infectious disease consultation may be required, especially in cases of unusual organisms or multidrug-resistant bacteria. 
In late presenting infections during the healing process or after, a more formal workup may be required to determine the extent of the infection. The usual laboratory studies should be performed, complete blood count (CBC), erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP) level. The majority of time these are elevated and thus are useful more as a means to monitor the responsiveness of the patient to treatment rather than for diagnostic purposes. These patients should have a CT scan of the pelvis and abdomen with contrast. This will allow one to assess for the location and extent of a possible abscess. Fracture healing should also be assessed as it may allow for hardware removal in cases where the bony injury has gone on to union. Due to associated hardware and the bony pathology initially treated, MRI is rarely used in the evaluation of postoperative pelvic infections. In cases where the fracture has clearly healed at time of presentation, nuclear medicine studies may be useful to determine the extent of bony and/or hardware involvement. A technetium bone scan, if positive, is followed by an indium scan. A colloid scan is then performed in cases of positive indium scans to further determine if an infection really exists or if it is reactive bone marrow. 
Late presenting infections should also undergo open incision, debridement, and irrigation as well. In cases where the fracture has healed, hardware removal should be strongly considered. Serial debridements with placement of antibiotic beads and use of negative pressure therapy can be used depending on the extent of the infection. Percutaneous drainage and antibiotic therapy alone should be reserved for the patient that is too sick because of age and/or comorbidity to undergo operative intervention. 

Newly Recognized Postoperative Neurologic Deficits

Many patients who undergo operative intervention may have undiagnosed preoperative neurologic deficits because a comprehensive exam cannot be performed secondary to their overall condition at the time of admission and in the early hospitalization. In addition, posterior pelvic ring fractures and dislocations can have subtle neurologic injuries, which may not come to light until the postoperative period. It is important to document the extent to which a preoperative neurologic examination could be accomplished. Similarly patients may continue to have mental status or associated injuries, which can also prevent the diagnosis of potential postoperative deficits. However, if a new postoperative neurologic deficit is recognized it can be difficult to manage. In such cases, a postoperative CT scan should be performed to assess for iatrogenic injury. Nerve root irritation or impingement could be occurring from (a) a screw, (b) a fragment of bone, or (c) iatrogenic overclosure of the foramen with compression of the nerve root. In some cases, there is no nerve root impingement and the deficit is the result of fracture manipulation and reduction. Due to the hardware that is present, an MRI is generally not useful. If further evaluation of the nerve roots is required, a postmyelogram CT scan can be performed. Treatment is dependent on the neurologic findings. With a motor deficit that corresponds to the site of potential nerve root compression, the offending bone or screw should be removed, which requires reoperation and possible hardware revision. Isolated radicular pain can be observed and the patient can be placed on medications such as gabapentin to control the neurogenic pain. In addition, steroids can be used to decrease the inflammation, which may be contributing to the pain. If there is no improvement over the next 2 to 3 weeks, the fixation should be revised or bone fragment removed. In the event of a new neurologic deficit without evidence of nerve root impingement, such cases should be managed with observation, pain medication, and physical therapy. When motor deficits occur, either splinting or tendon transfers may be needed depending on the severity of the deficit and muscle groups involved. 

Pin-Tract Infections

Unfortunately superficial pin tracts can be the norm when patients are treated with external fixation. Daily pin care and vigilance are required. After the initial 2-week postoperative period, and once any associated incisions are healed, patients can shower. Pin care in obese patients are especially problematic because of the excessive soft tissue around the pins. Dry dressings and gauze wrapped around the pin seems to work the best in our anecdotal experience. We do not recommend saline or hydrogen peroxide. Superficial pin tracts can be managed with antibiotics alone; usually a 10 to 14 day course of Keflex (noncephalosporin or penicillin allergic) or clindamycin will suffice. Deeper infections, evident on loosening around the pins on radiographs or gross purulence, may require revision of the fixation with new pins being placed at another site. These infections will require much more aggressive treatment with irrigation, debridement, and intravenous antibiotics. If supra-acetabular pins are used and become infected, pins in the anterior iliac crest may have to suffice. 
The importance of proper pin care cannot be overemphasized to the patient as well as prompt notification to the provider such that antibiotics can be started. Educating the patient as to the probable occurrence of the pin-tract infection can decrease the anxiety for the patient when it does happen. Most infections resolve with a course of oral antibiotics. Realize that during the 6- to 12-week treatment of the pelvic ring injury, several courses may be required. 

Deep Venous Thrombosis/Pulmonary Embolism Prophylaxis

Trauma patients are at high risk for the development of venous thromboembolic (VTE) events. It is clear that some sort of prophylaxis is required in the prevention of VTE events in the care of trauma patients, especially those with pelvic ring fractures.28,122,268,313,344 Mechanical prophylaxis in the form of intermittent pneumatic compression devices applied to the lower extremities can help prevent venous thrombus formation318,319 and should be used in all trauma patients if lower extremity injuries do not prevent their use.122 However, the prevention of deep vein thrombosis (DVT) and pulmonary embolus (PE) with chemoprophylaxis continues to be a controversial topic. There is no clear consensus among surgeons as to who should receive prophylaxis, when they should receive it, and in what form, although 99% use something postoperatively and 88% preoperatively in pelvic and acetabular fractures.216 There are also geographic discrepancies from our colleagues in the United Kingdom, further accentuating the lack of a standard of care in this realm.121 The difficulty in decision making has been compounded by a lack of scientific evidence in the literature.268,313,344 At present the guidelines from Chest (The American College of Chest Physicians)122 make recommendations for trauma patients as a whole without discerning those individuals that have pelvic ring fractures. Patients with major trauma should have low-dose unfractionated heparin (LDUH), low-molecular-weight heparin (LMWH), or intermittent pneumatic compression devices (IPCDs). If considered high-risk (pelvis not explicit risk factor), patients should receive both chemophylaxis and mechanical prophylaxis. However, patients undergoing major orthopaedic surgery, total hip arthroplasty, total knee arthroplasty, or hip fracture surgery should all receive 10 to 14 days of chemoprophylaxis postoperatively or an IPCD, but one that can monitor “wear” time to ensure that it was being used for 18 hours per day. Unfortunately, pelvic ring fractures were not considered as a separate category, although it has been considered as a strong risk factor for developing a VTE event when looking at the risk assessment profile (RAP) as defined by Greenfield et al.113 (Table 46-8). It has been shown patients with a RAP score of 5 or more have a threefold chance of developing VTE compared to those with a RAP less than 5.98 The pelvic component alone in the RAP is 4 points. Considering most patients with pelvic ring fractures have other conditions listed in the RAP, they easily can exceed the 5-point threshold.344 Additional studies also suggest that patients with pelvic ring fracture are at high risk.81,320,325 In looking at the German Trauma registry of >35,000 patients, Paffrath et al.231 evaluated a subgroup of 7,937 patients with complete data sets and found that a pelvic ring fracture was an independent risk factor for the development of a VTE. These studies suggest that patients with pelvic ring fracture patients should have some type of prophylaxis started within 12 to 24 hours of pelvic injury.122,319,320 This can be in the form of LMWH or LDUH given subcutaneously325 alone or in combination with an ICPD.122 A dual approach with the ICPD started acutely followed by chemoprophylaxis in a delayed fashion was also shown to be effective.318 The author’s preference is to utilize both ICPD and LMWH in all trauma patients with pelvic ring injuries, barring all other contraindications. 
 
Table 46-8
Risk Assessment Profile
View Large
Table 46-8
Risk Assessment Profile
Risk Factors Points
Age
40–60 2
61–75 3
>75 4
Underlying Conditions
Obesity 2
Malignancy 2
Abnormal coagulation 2
History of thromboembolism 3
Injury-Related Factors
Chest AIS >2 2
Abdomen AIS >2 2
Head AIS >2 2
Spinal fractures 3
Glascow Coma Scale <8 3
Severe lower extremity fracture 4
Pelvic fracture 4
Spinal cord inury 4
Iatrogenic Factors
Femoral venous line 2
Operation >2 hours 2
Transfusion >4 units 2
Major venous repair 3
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Inferior vena cava filters have also been used in trauma patients as a method of preventing PE and has been found to be safe and effective with relatively low rates of complications.107,253 The use of IVC filters as a method for VTE prophylaxis is controversial and should not be used as a first line of defense.122 These devices certainly does not prevent DVT, but they are placed in hopes of preventing a PE, especially in those patients who are unable to receive anticoagulation because of sensitivity or associated head, chest, or abdominal trauma. It is important to note that although IVC filters can reduce the incidence of PE, they have not been shown to improve survival or affect the incidence of fatal PE.253 Pelvic ring fracture has been considered an indication for a prophylactic filter, which at present tends to be a filter that can be removed within 3 to 6 months depending on the manufacturer and clinical situation.107 Retention of the filter has been a concern because of the potential development of postphlebitic syndrome,253 although the majority of this outcome has been reported in nontrauma patients. Toro et al.348 showed that in a group of trauma patients with IVC filter, the incidence of postthrombotic syndrome was 1%. 
Diagnosing a DVT prior to the development of a PE can be problematic. Many have discussed the use of screening studies such as a Duplex Doppler, contrast venography, and magnetic resonance venography.20,212,330 Unfortunately screening studies have not been shown to be efficacious in patients with pelvic ring fractures.20,208,331 but may be of some benefit in the patient without prior or suboptimal thromboprophylaxis.206 The use of Duplex ultrasound is not recommended as a routine screening tool without clinical evidence of a DVT.122 In the event a patients with pelvic ring fracture does develop a preoperative DVT confirmed with Duplex, these patients should undergo IVC filter placement as a means to prevent a PE.348 
The need for, type of, and amount of chemoprophylaxis required for the prevention of VTE on an outpatient basis on discharge after the acute trauma is ill-defined.216 The 2012 Chest guidelines do indicate that in the case of major orthopaedic surgery, outpatient prophylaxis should be extended up to 35 days from surgery.122 Whether this can be extrapolated to the trauma patient remains to be seen. In determining the need for prolonged outpatient therapy, one must consider a multitude of risk factors: Ambulatory status, age older than 40 years, body mass index >30 kg/m2, female sex, birth control pills or hormone replacement therapy, adenocarcinoma or malignancy, prior history of DVT/PE, and smoking.122,344 In the majority of pelvic trauma patients who required operative intervention and have other risk factors, some sort of anticoagulation should be continued for at least 4 to 6 weeks. In the patient with a stable pelvic ring fracture in which weightbearing as tolerated is allowed, a short duration (2 weeks) of chemoprophylaxis should probably be considered. The use of aspirin and elastic stockings are considered inadequate discharge thromboprophylaxis.122 In patients with pelvic ring injuries with or without associated lower extremity injuries, which prevent ambulation on both sides, consideration should be given to at least 6 weeks if not 12 weeks of chemoprophylaxis. 

Outcomes

Studies evaluating outcomes are difficult to interpret due to the heterogeneity in patient populations reported. These patients have associated injuries, which confound the outcomes related to the pelvic injury itself.60 It is unclear as to the affect a malreduction has on the functional outcome.70,217,220,346 If reduction of the posterior ring can be obtained within 1 cm, the long-term functional results are improved.70,131,217,308,346 This is especially true for pure dislocations of the SI complex. However, fractures of the posterior ring do better than dislocations because it is felt that bony healing can restore the normal stability,48 as opposed to pure SI dislocations, which rely purely on scar formation for ligamentous healing. If those patients do develop a bony ankylosis of the SI joint dislocation, the outcome was not improved over those that did not ankylose the joint.217 The true effect of an anatomic reduction is still difficult to ascertain because many studies lack standardization of interpreting the radiologic outcome with regard to reduction.170 This is evident in the fact that despite seemingly reported anatomic reductions, clinical outcome studies have shown that a substantial proportion of patients continue to have poor outcomes with chronic posterior pelvic pain.48,59,70,131,144,217,220,248 Timing may have some effect on functional outcome due to the ease of obtaining a better reduction with early fixation.148 Return to work is extremely variable with severe pelvic ring fractures, but the majority of patients do have some persistent impairment long term.120,131,228,248,360 
Given the multiply injured nature of the patient with a pelvic ring fracture, a number of multiple confounding variables can lead to the poor outcomes seen.59,65,144 A significant factor in poor outcomes is related to the associated urogenital, neurologic, and visceral injuries. Male patients report erectile dysfunction whereas female patients report dyspareunia, urinary difficulty, and child-bearing issues with some concern for increased need for cesarean sections.55,144,179,258,358 Bladder rupture and associated lower extremity injuries were associated with worse outcomes in women.358 Regardless of gender, many of these patients also have psychological issues including anxiety and depression that should be addressed as well.144 
Mortality after pelvic ring fractures is often secondary to other associated life-threatening injuries.5,133,269 However, certain fracture patterns and patient characteristics have an increased rate of mortality but may be attributable to the other injuries. The Tile C fracture was found to have a significant increase in mortality.45,133,144,269 A higher mortality rate is reported in elderly patients, presumed to be due to their comorbidities,45,226 but this was recently questioned.133 Male gender was also associated with a higher mortality rate.133 

Author’s Preferred Treatment

 
 
Anterior Pelvic Injuries (Fig. 46-92)
 
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Figure 46-92
Algorithm for anterior injury.
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Symphyseal Diastasis
 

Our preferred treatment is for open reduction and internal fixation in cases where the disruption is >2.5 cm, utilizing a 4- or 6-hole locking symphyseal plate. In the nonobese patient, internal fixation is preferred. In the obese patient, wound complications tend to be problematic, and if the patient does not have a large pannus, external fixation is used. They do require vigilant pin care however. We also utilize external fixation in young female patients, especially if future child-bearing desire is indicated. As implants and systems become available for the internal external fixator, our preference would be to utilize this method in all patients in whom ORIF may be problematic. In patients with associated bladder rupture, external fixation is used due to the management of the bladder rupture with nonoperative means. In the event bladder repair is performed, simultaneous ORIF can be considered.

 
Superior Rami Fractures
 

If there are rami fractures in which stabilization is required, antegrade or retrograde screw fixation is used depending on the amount of comminution, bone quality, displacement, and location of the fracture. High pubic root fractures are treated with anterior column screws, whereas more parasymphyseal fractures are treated with retrograde pubic screws. In patients with straddle fractures with significant comminution or osteopenia, anterior external fixation or internal external fixation is preferred.

 
Posterior Pelvic Injuries (Fig. 46-93)
 
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Figure 46-93
Algorithm for posterior treatment.
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Sacroiliac Dislocations
 

Closed reduction and percutaneous skeletal fixation with iliosacral screws are preferred if an anatomic reduction can be obtained. Transsacral screws are used in cases when (a) bilateral injuries where sides are reduced easily closed and can be held reduced with pelvic sheeting, and there is insufficient room for two independent screws; (b) poor screw purchase in the sacrum; and (c) SI joint dislocation with contralateral, complete nondisplaced sacral fracture. If there is any issue with obtaining an anatomic reduction closed, then an open reduction via the lateral window of the ilioinguinal approach is used. Percutaneous screw fixation is still the implant of choice.

 
Sacroiliac Fracture Dislocations “Crescent Fracture”
 

The preferred treatment is based on the classification based on size: Type I, II or III. The type I crescent is treated with ORIF through an anterior approach. The type II injury requires ORIF through a posterior approach. The type III fracture dislocation will undergo formal ORIF through a posterior approach for screw fixation to the remaining ilium with supplemental SI screw fixation if indicated.

 
Iliac Wing Fractures
 

Iliac wing fractures that require operative fixation undergo open reduction and internal fixation via an anterior approach. Occasionally, if the anterior soft tissues preclude incisions, then a posterior approach can be performed.

 
Sacral Fractures
 

Complete sacral fractures that are nondisplaced or can be reduced closed with manipulation are treated with percutaneous iliosacral screw fixation. In displaced, complete fractures, posterior fixation is supplemented with anterior fixation in the form of an external fixator to help reduce the stress on the screw. Often, two iliosacral screws will also be used in these cases. If triangular osteosynthesis is warranted, fixation is performed in conjunction with our neurosurgical colleagues. If any neurologic deficit is present and can be correlated with nerve root foraminal impingement secondary to bone fragments based on CT scan or concern for L5 nerve root invagination into the alar fracture and subsequent compression with screw fixation, the patients will undergo decompression and open reduction followed by iliosacral screw fixation. Sacral fractures are approached posteriorly to decompress the sacral nerve roots, whereas the lateral window is used to extract the L5 nerve root from the anterior sacral ala fracture. Transiliac screws are utilized in the following cases: (a) Bilateral complete sacral fractures that are nondisplaced, (b) poor screw purchase within the sacrum, and (c) insufficient room for two screws in bilateral cases.

 

Two screws versus one screw: The use of two screws is done on a case by case basis and is generally reserved for cases of extensive sacral fracture comminution, significant displacement, and/or poor bone quality. If there is insufficient room for two screws from opposing sides, a second screw opposite the side of the transsacral screw may be placed at the S2 level for added stability. In addition, in cases of sacral dysmorphism, the traditional S1 screw, if it can be placed safely, is placed at an angle up into the ala and it is hoped into the body, but it is usually much shorter. Alar screws have been shown to be biomechanically inferior.160 Thus a second screw is placed in the S2 level to supplement the fixation. However, routinely, the S2 screw will be the first level of fixation in the dysmorphic pelvis.

 

Spinopelvic instability: In cases of completely nondisplaced sacral fractures that are consistent with true spinopelvic disassociation without kyphosis, a multidisciplinary approach is utilized and discussion with our neurosurgical colleagues occurs. Often, percutaneous iliosacral screw fixation is used in these cases. Otherwise, if spinopelvic fixation is warranted, it is performed by our neurosurgery service in our institution.

Controversies and Future Directions

Since the publication of the last edition, many of the controversies mentioned have not been addressed to date. The number of iliosacral screws for unstable pelvic ring injuries,204,247,287,304,361,376 the order of fixation (anterior vs. posterior first), and open versus closed reduction continue to be areas in which no clear answer exists. Although pelvic surgeons do agree and believe that an anatomic reduction should be obtained for the best possible outcome and that earlier fixation allows that to be accomplished easier, the published literature has not confirmed these anecdotal viewpoints with Level I evidence. 
The newest areas of controversy, as indicated in this chapter, are with regard to the resuscitation phase in managing pelvic ring injuries, specifically the use of pelvic packing or angiography, although we believe that their uses are probably complementary rather than competitive. The internal external fixator’s place in the management of pelvic ring injuries will also need to be better defined, but early reports have been promising. Prospective studies between this new technique, anterior plating, and traditional external fixation for treatment of anterior ring injury are warranted and it is hoped they will provide insight into the best practice. For now, the use of iliosacral screws for posterior fixation and plate fixation for anterior injuries seems to be accepted as the optimal situation when feasible, assuming that anatomic reduction is obtained. 
The order of the fixation continues to be a constant area of debate, not only among surgeons, but also in one’s own practice. Traditionally, the posterior ring has been felt to be the more critical injury requiring the best reduction possible first, followed by operative stabilization of the anterior ring.175,176 The concern is that rigid fixation of the anterior ring first, especially if malreduced, will subsequently prevent a proper posterior reduction. Surgeons who believe that the anterior injury should be fixed first, argue that fixation anteriorly will aid in the posterior reduction, allowing one to obtain a reduction closed, and then maintaining it with percutaneous stabilization, screws, or percutaneous plate.162 Fundamentally, both views are correct and it is clear that each technique has its advantages and disadvantages. We believe that surgeons should consider both strategies and based on the injury pattern, patient factors such as soft tissue injuries or associated injuries (may restrict patient positioning), and the surgeon’s abilities and experience determine which order is best for the patient to minimize morbidity. 
Similarly, controversy exists in the management of patients who have concomitant acetabular and pelvic ring injuries as to which fracture should be fixed first.335 The investigators report that during a 9-year period, 82 patients had both injuries treated at a Level 1 trauma center. The majority of the acetabular fractures were transverse types, and the pelvic injury was classified as OTA 61B1 and B2 injuries. Residual postoperative acetabular displacement was felt to be associated with amount of posterior pelvic displacement, patient age, and the OTA 62B type acetabular fractures. The authors felt that optimal reduction of the acetabulum was predicated on accurate reduction of the posterior pelvis, suggesting that the pelvic injury be treated first. We recommend the “easier” fracture be reduced first, as that will ensure an anatomic reduction of the first injury, which should aid in the reduction of the second injury. Simultaneous fixation of both injuries can also be beneficial in certain injury patterns. Either way, anatomic reduction is clearly associated with improved outcomes for acetabular fractures and that should remain a priority. 
The acceptance of a “near anatomic reduction” with closed means versus an absolute open anatomic reduction is still controversial. There certainly are theoretical problems associated with each: Increased blood loss, complications, and soft tissue problems for an open approach and potential worse outcomes with near-anatomic reductions. Unfortunately the current literature is still difficult to interpret for the reasons previously mentioned. One of the limiting factors in obtaining closed anatomic reductions is our ability to visualize and interpret the images we see with fluoroscopy. Improved imaging techniques and the potential use of image-guided surgery have been mentioned as ways to improve the evaluation of closed reductions. The use of CT-guided screw placement was an early attempt to improve visualization and assessment of the reduction, but the logistics of the procedure were not conducive to allowing manipulative reduction,280 and there have been concerns with the increased radiation associated with CT.273 The use of 2D and 3D c-arm navigation has also been tried, but the image size, quality, need for reduction prior to use, and the need for navigation markers were limitations.327 Use of various imaging techniques for placement of the screw in cases where the reduction has been achieved has certainly been shown to be successful97; however, allowing visualization of the reduction during manipulation continues to be problematic. It is hoped that newer techniques and imaging modalities will allow simultaneous real-time visualization of reduction and stabilization of pelvic ring fractures, while minimizing radiation and operative times. 
Recently, the issue of the management of pelvic ring fractures secondary to gunshot wounds in the civilian setting has come up for some discussion about the best management. Historically, low velocity gunshot wounds in the extremities have been managed nonoperatively, assuming that an associated fracture requiring fixation was not present, with variable use of antibiotics. The frequency of involvement of the pelvis in gunshot wounds seems to be increasing in some centers and thus the controversy now extends to this area of the body. Two recent retrospective reports9,366 indicate the majority of the morbidity and mortality is related to the nonorthopaedic injuries associated with gunshots around the pelvic area such as vascular, visceral, or urogenital injuries. Unstable pelvic injuries were rare and the development of osteomyelitis unlikely, even in the absence of surgical debridement for the pelvic ring fracture. Removal of bullet fragments was felt to be unnecessary, unless there was joint involvement and retention did not increase the risk of infection. Associated gastrointestinal injuries with potential contamination may be an indication for surgical debridement of the fracture as well as antibiotics, but due to the fracture pattern stabilization this was not needed. Both studies were limited due to the retrospective nature, thus larger studies are warranted. The best treatment remains to be determined. 
Pelvic ring fracture treatment continues to be an area of dynamic changes. Continued innovation in operative techniques, newer technology, both implants and imaging, will hopefully allow for improvements in the management of these potentially life-altering injuries. Larger prospective multicenter studies that evaluate functional outcomes with various operative techniques are needed. In the meantime, pelvic ring fractures are best treated at large trauma centers by experienced pelvic surgeons in hopes of obtaining the best outcome for the patient. 

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