Chapter 48: Hip Dislocations and Fractures of the Femoral Head

Michael S. Kain, Paul Tornetta, III

Chapter Outline

Introduction to Hip Dislocations and Fractures of the Femoral Head

The hip joint is inherently stable, requiring significant force to dislocate. Thus, pure hip dislocation or dislocation with femoral head fracture is generally a result of high-energy trauma and is often accompanied by associated injuries that must be recognized.96 Suraci201 reported that 95% of patients presenting with hip dislocation after a motor vehicle accident had an associated injury requiring inpatient management. All patients require a standard trauma evaluation, a meticulous musculoskeletal and neurologic examination and detailed radiographic assessment to avoid missing injuries. 
Outcome is dependent on many variables.3,17,28,80,209 Some, such as cartilage damage at impact and injury to the femoral head vascular supply, are beyond the control of the surgeon. Others, such as the timing and accuracy of the reduction, are variables that can be positively affected by recognizing and treating the dislocation as an emergency. Poor outcomes and complications are common and include avascular necrosis (AVN), arthritis, neurologic injury, heterotopic ossification, and redislocation.3,17,28,40,43,53,82,94,151,209 Even if short-term complications such as loose body wear and AVN are avoided, the long-term outcome of hip dislocation is not predictably good. The incidence of unsatisfactory results, primarily as a consequence of arthritis, has been reported as high as 50%.43,231 The treatment of hip dislocations and femoral head fractures is directed toward avoiding complications by emergent reduction and by providing a congruent and stable joint. 

Assessment of Hip Dislocations and Fractures of the Femoral Head

Mechanisms of Injury for Hip Dislocations and Fractures of the Femoral Head

The vast majority of hip dislocations occur from high-energy motor vehicle trauma. Unrestrained drivers may be at a higher risk for hip dislocation than restrained drivers.27 Other mechanisms include falls, pedestrians struck by motor vehicles, industrial accidents, and athletic injuries.55,63,140,148,196,201,206 There has been an increased incidence of reporting dislocations and hip injuries as a result of athletic activities, but this does not decrease the severity of these injuries. 
The position of the hip, the force vector applied, and the individual’s anatomy all affect the direction of the dislocation and whether a fracture–dislocation or pure dislocation occurs (Table 48-1).31,40,46,51,53,56,57,118,119,153,157,196,215 Posterior dislocations out number anterior dislocations by approximately nine to one.9,17,43,206,231 The typical mechanism for a posterior dislocation is a deceleration accident in which the occupant’s knee strikes the dashboard with both the knee and hip flexed. Letournel118,119 used vector analysis to explain that the more flexion and adduction the hip is in when a longitudinal force is applied through the femur, the more likely a pure dislocation will occur (Fig. 48-1).118,119 Less adduction or less internal rotation favor a fracture–dislocation, which may occur with a posterior wall fracture or a shearing injury of the femoral head as the head impacts against the posterior wall. The latter case results in a Pipkin-type injury with a fragment of the femoral head remaining in the acetabulum and the intact portion dislocating posteriorly. 
Figure 48-1
The position of the hip during axial loading determines the type of injury.
 
Increasing flexion, adduction, and internal rotation favors pure dislocation, whereas lesser degrees of each leads to fracture–dislocation.
 
(Adapted from: Letournel E, Judet R. Fractures of the Acetabulum. 2nd ed. New York, NY: Springer Verlag; 1993.)
Increasing flexion, adduction, and internal rotation favors pure dislocation, whereas lesser degrees of each leads to fracture–dislocation.
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Figure 48-1
The position of the hip during axial loading determines the type of injury.
Increasing flexion, adduction, and internal rotation favors pure dislocation, whereas lesser degrees of each leads to fracture–dislocation.
(Adapted from: Letournel E, Judet R. Fractures of the Acetabulum. 2nd ed. New York, NY: Springer Verlag; 1993.)
Increasing flexion, adduction, and internal rotation favors pure dislocation, whereas lesser degrees of each leads to fracture–dislocation.
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Table 48-1
Direction of Hip Versus Injury Pattern
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Table 48-1
Direction of Hip Versus Injury Pattern
Flexion, adduction, IR Pure posterior dislocation
Partial flexion, less adduction, IR Posterior fracture dislocation
Hyperabduction, extension, ER Anterior dislocation
 

IR, internal rotation of the hip; ER, external rotation of the hip.

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The concept that the position of the head at impact plays a large role in the type of injury is supported by Upadhyay215 and colleagues, who studied the femoral anteversion in patients with hip dislocations and fracture–dislocations. They observed a decrease in femoral anteversion and even femoral retroversion in patients who sustained fracture–dislocations compared to a normal population and even less femoral anteversion in patients who sustained pure dislocations. Decreased anteversion acts to place the head in a more posterior position as does internal rotation, both tending to produce a pure dislocation. Conversely, greater anteversion and less internal rotation led to fracture–dislocation. 
The less common anterior dislocations are the result of hyperabduction and extension.52,157 This mechanism may be present in deceleration injuries in which the occupant is in a relaxed position during impact with the legs flexed, abducted, and externally rotated, as well as in motorcycle accidents where the legs are frequently hyperabducted. Using cadavers, Pringle and Edwards157 were able to cause anterior hip dislocations by hyperabduction and external rotation. The degree of hip flexion determined the type of anterior dislocation, with extension leading to a superior pubic dislocation and flexion resulting in an inferior obturator dislocation. 
Recent attention has been paid to athletics as a cause of both dislocations and femoral head fractures. Moorman et al.140 reported on eight American football players who sustained a posterior hip subluxation, primarily from a fall on the knee with the hip adducted. They describe a characteristic triad of magnetic resonance imaging (MRI) findings, including a small posterior wall fracture, rupture of the iliofemoral ligament, and hemarthrosis as being diagnostic.140 Aspiration was recommended for large hemarthrosis as two of the eight went on to severe AVN and hip replacement. Matsumoto et al.131 reviewed a large experience of skiing and snowboarding injuries. The incidence of dislocation from snowboarding was five times higher than skiing (0.45 vs. 0.09/100,000). In addition, snowboarding injuries were more commonly posterior dislocations and 30% had femoral head fractures. Femoroacetabular impingement may also play a role in hip instability. The exact role is unclear, but the underlying bone morphology maybe a contributing factor in these hips. Decreased femoral head-neck offset (CAM type) or a deep acetabulum (PINCER type) may exist in these athletes who sustain a hip dislocation or even a subluxation.13,107 
Fatigue fractures of the femoral head may also occur, and their mechanism is often less obvious than high-energy trauma. They occur in patients with osteopenia, but may occur in healthy adults when beginning a new exercise regimen.22,38,117,168,188,200,221 These are reported as “subchondral impaction” or “insufficiency” fractures, but represents a significant injury to the femoral head. Song et al.188 and Visuri et al.221 have reported a combined 17 cases of insufficiency fracture in military recruits. Most were diagnosed on MRI, but several presented with collapse seen on plain radiographs. Fourteen of the 17 had good results, but two went on to total hip arthroplasty. 
Finally, cases of bilateral hip dislocation, with and without femoral head fracture have been reported, as well as cases of femoral head with and without femoral neck fractures without dislocation.4,47,83,97,98,128,137,167,176,210 

Associated Injuries with Hip Dislocations and Fractures of the Femoral Head

Patients presenting with a hip dislocation or femoral head fracture should be presumed to have multiple injuries. Up to 95% of these patients have injuries that require inpatient management independent of their dislocation.201 Intra-abdominal, head, and chest trauma are common associated injuries. In addition, Marymont et al.126 described the association of thoracic aortic injury in combination with posterior hip dislocations. Despite a typical presentation, including extremity deformation, the diagnosis of hip dislocation may be delayed due to more life-threatening associated injuries. 
Common associated skeletal injuries include femoral head, neck, or shaft fractures, acetabular fractures, pelvic fractures, knee injuries, ankle and foot injuries, and neurologic injuries (Table 48-2). Knee injuries including posterior dislocation, cruciate ligament injuries, and patellar fractures are common with posterior hip dislocations due to direct trauma with the dashboard at impact (Fig. 48-2). Tabuenca et al.204 reported that 25% of 187 patients with hip dislocations and fracture dislocations sustained a major knee injury. Seven of these injuries were not diagnosed at the time of the initial hospital stay. Patients should be treated with spinal precautions until the spine has been radiographically cleared of injury. In the absence of femoral shaft or neck fractures, the position and mobility of the extremity may indicate a dislocation. In a posterior dislocation, the leg is flexed, adducted, and internally rotated. Any motion of the hip, particularly attempts to extend or externally rotate the hip, is exceedingly painful. Conversely, anterior dislocations present with the extremity externally rotated with varied amounts of flexion and abduction. 
Figure 48-2
Photograph of a patient presenting after a dashboard injury.
 
The patient sustained an open knee injury from the incident. The leg was flexed and internally rotated, indicating a possible posterior hip dislocation.
The patient sustained an open knee injury from the incident. The leg was flexed and internally rotated, indicating a possible posterior hip dislocation.
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Figure 48-2
Photograph of a patient presenting after a dashboard injury.
The patient sustained an open knee injury from the incident. The leg was flexed and internally rotated, indicating a possible posterior hip dislocation.
The patient sustained an open knee injury from the incident. The leg was flexed and internally rotated, indicating a possible posterior hip dislocation.
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Table 48-2
Common Associated Fractures
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Table 48-2
Common Associated Fractures
Pelvic ring fractures
Femoral neck fractures
Acetabular fractures
Femoral head fractures
Knee ligament injuries
Spine injuries
Femoral shaft fractures
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Associated injuries dictate treatment in most cases of hip dislocation. Proper diagnosis of these injuries and their potential influence on treatment is paramount. This begins with associated fractures that may affect the ability of the surgeon to obtain a closed reduction by manipulation of the lower extremity. Nondisplaced femoral neck fractures are the most difficult of these to diagnose and are a major potential pitfall. High quality radiographs of the femoral neck in profile (15-degree internal rotation view) and occasionally, a computed tomography (CT) scan with fine cuts (2 mm) are needed to rule out occult femoral neck fracture before manipulative closed reduction is attempted. Fixation of the neck may be needed prior to attempts at closed reduction of the hip (Fig. 48-3). 
Figure 48-3
 
AP radiograph of a 36-year-old who sustained a posterior hip dislocation, impaction of the femoral head, and a minimally displaced valgus femoral neck fracture in addition to type 2 anteroposterior compression pelvic injury (A). The patient was brought emergently to the operating room where the femoral neck was fixed with percutaneous screws prior to reduction (B). After fixation, the hip was able to be reduced closed (C). At 6 months, the patient had no signs and symptoms of AVN and minor posterior pelvic pain (D).
AP radiograph of a 36-year-old who sustained a posterior hip dislocation, impaction of the femoral head, and a minimally displaced valgus femoral neck fracture in addition to type 2 anteroposterior compression pelvic injury (A). The patient was brought emergently to the operating room where the femoral neck was fixed with percutaneous screws prior to reduction (B). After fixation, the hip was able to be reduced closed (C). At 6 months, the patient had no signs and symptoms of AVN and minor posterior pelvic pain (D).
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Figure 48-3
AP radiograph of a 36-year-old who sustained a posterior hip dislocation, impaction of the femoral head, and a minimally displaced valgus femoral neck fracture in addition to type 2 anteroposterior compression pelvic injury (A). The patient was brought emergently to the operating room where the femoral neck was fixed with percutaneous screws prior to reduction (B). After fixation, the hip was able to be reduced closed (C). At 6 months, the patient had no signs and symptoms of AVN and minor posterior pelvic pain (D).
AP radiograph of a 36-year-old who sustained a posterior hip dislocation, impaction of the femoral head, and a minimally displaced valgus femoral neck fracture in addition to type 2 anteroposterior compression pelvic injury (A). The patient was brought emergently to the operating room where the femoral neck was fixed with percutaneous screws prior to reduction (B). After fixation, the hip was able to be reduced closed (C). At 6 months, the patient had no signs and symptoms of AVN and minor posterior pelvic pain (D).
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Similarly, associated pelvic ring fractures may make counter-traction impossible, necessitating open reduction of the dislocation (Fig. 48-4). Injury to the knee is usually apparent on careful clinical examination and confirmed with radiographic evaluation. Associated fractures of the hip itself, such as acetabular wall fractures and femoral head fractures, may require surgical intervention even if the hip dislocation is reduced closed. Femoral head fractures or loose bodies from the head or acetabulum may cause an incongruent reduction of the hip. Acetabular wall fractures may allow for clinical instability even in the face of a congruent reduction and require fixation. While this chapter does not cover the indications and techniques of posterior wall reduction and fixation, the determination of hip stability in the presence of a posterior wall fracture is important. This is discussed below (see “Techniques for Closed Reduction” and the subsection “Flouroscopic Evaluation of the Hip following Closed Reduction.”) and is included in the treatment algorithm. 
Figure 48-4
 
A 23-year-old with an open hip fracture–dislocation with associated pelvic fractures including a symphyseal dislocation, and an ipsilateral fracture–dislocation of the sacroiliac joint. This requires open reduction.
A 23-year-old with an open hip fracture–dislocation with associated pelvic fractures including a symphyseal dislocation, and an ipsilateral fracture–dislocation of the sacroiliac joint. This requires open reduction.
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Figure 48-4
A 23-year-old with an open hip fracture–dislocation with associated pelvic fractures including a symphyseal dislocation, and an ipsilateral fracture–dislocation of the sacroiliac joint. This requires open reduction.
A 23-year-old with an open hip fracture–dislocation with associated pelvic fractures including a symphyseal dislocation, and an ipsilateral fracture–dislocation of the sacroiliac joint. This requires open reduction.
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Signs and Symptoms of Hip Dislocations and Fractures of the Femoral Head

The examination specific to the hip dislocation should begin by observing the position of the patients’ legs. Typically, the involved leg is foreshortened and excessively rotated, either externally rotated in an anterior dislocation or internally rotated in posterior dislocations. Large areas of ecchymosis may be observed around the abdomen, proximal thigh, or knee. Once there is a concern for a hip dislocation palpation of all long bones and joints of the affected extremity along with a meticulous neurologic and vascular examination is required. A thorough knee examine is also paramount, as there is a high association of ligamentous knee injuries and the presence of a large transverse laceration is another indication that a hip dislocation may have occurred. Emphasis on the prereduction function of the sciatic nerve is paramount in posterior dislocations as the nerve can be injured during reduction.18,55,85,113,195,196 Careful testing of all branches is required, including foot eversion, as weakness in the peroneals may be an isolated finding. Posterior dislocations are associated with posterior knee dislocations, and, although rare, anterior dislocations may injure the femoral vessels, necessitating a careful assessment of distal pulses. Finally, the spine and pelvis should be examined. Although injury to these areas may be clinically apparent, they cannot be ruled out without radiographic studies. 

Imaging and Other Diagnostic Studies for Hip Dislocations and Fractures of the Femoral Head

The first study available is usually the anteroposterior (AP) pelvis radiograph. This is usually taken as part of the initial trauma workup and helps the direct treatment. The diagnosis of hip dislocation should be apparent on this single radiographic view (Fig. 48-5). The key to the diagnosis on the plain AP pelvis is the loss of congruence of the femoral head with the roof of the acetabulum. On a true AP view, the head will appear larger than the contralateral head if the dislocation is anterior and smaller if posterior. The most common finding, in the case of a posterior dislocation, is a small head that is overlapping the roof of the acetabulum. In an anterior dislocation, the head may appear medial to or inferior to the acetabulum. 
Figure 48-5
The trauma AP pelvis radiograph demonstrates a patient with a posterior dislocation of the right hip.
 
Note the superior location of the femoral head and the internally rotated proximal femur.
Note the superior location of the femoral head and the internally rotated proximal femur.
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Figure 48-5
The trauma AP pelvis radiograph demonstrates a patient with a posterior dislocation of the right hip.
Note the superior location of the femoral head and the internally rotated proximal femur.
Note the superior location of the femoral head and the internally rotated proximal femur.
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Although significant flexion may diminish the findings, rotation is also detectable on the single AP view. The lesser trochanter is less apparent and the femoral neck is seen in profile when the femur is internally rotated (Fig. 48-5). It is critical that the initial radiograph be of good quality and carefully inspected for associated injuries before a reduction is attempted. In particular, associated femoral neck fractures, which may be nondisplaced, must not be overlooked. Likewise, associated femoral head fractures are usually visible as a retained fragment in the joint. Acetabular fractures and pelvic ring injuries are also visible on the plain AP radiograph. Additional radiographic assessment is not usually indicated before attempts at reduction unless a femoral neck fracture cannot be ruled out or there is a clinical suspicion of a femur, knee, or tibial injury that will affect the ability to use the extremity to manipulate the hip. In such cases, biplanar radiographs of all questionably affected areas must be obtained. 
The remainder of the plain radiographs and CT scan of the hip are deferred until after the hip is reduced, unless the hip is irreducible or there is a question of femoral neck fracture. If the hip cannot be reduced, then it is advantageous to obtain a preoperative radiographic series and CT scan to help in the diagnosis of offending structures and to look for the possibility of loose bodies in the joint or associated fractures that would require removal or fixation during open reduction. 
After the hip is reduced, all five standard views of the pelvis are obtained. Radiographs should include AP, both Judet (45-degree oblique) views (Fig. 48-6), and an inlet and outlet of the pelvis. It is best to focus the beam in the center of the pelvis, as this allows for a direct comparison of the affected hip with the normal hip when examining congruence and joint space. When evaluating each of these views, the first issue is whether there is a concentric reduction of the hip. The use of the contralateral hip is necessary to answer this question. Using the relationship of the femoral head to the acetabular roof (sourcil) on each view, the congruency of the hip is evaluated by comparing it to the contralateral side. This relationship should show no loss of parallelism. In addition, the joint space should be equal to the contralateral hip. The evaluation of these views for pelvic and acetabular fractures is discussed elsewhere in the text (Chapters 46 and 47). 
Figure 48-6
A 53-year-old woman with a posterior hip dislocation demonstrating fragments in the joint prior to hip reduction and an inferior femoral head fracture (A).
 
The postreduction AP and Judet views (B–D) demonstrate a widened joint space compared with the normal side and an incongruent reduction. Note that there are fragments both superior and inferior in the joint and that there is a loss of parallelism of the femoral head and acetabular articular surfaces.
The postreduction AP and Judet views (B–D) demonstrate a widened joint space compared with the normal side and an incongruent reduction. Note that there are fragments both superior and inferior in the joint and that there is a loss of parallelism of the femoral head and acetabular articular surfaces.
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Figure 48-6
A 53-year-old woman with a posterior hip dislocation demonstrating fragments in the joint prior to hip reduction and an inferior femoral head fracture (A).
The postreduction AP and Judet views (B–D) demonstrate a widened joint space compared with the normal side and an incongruent reduction. Note that there are fragments both superior and inferior in the joint and that there is a loss of parallelism of the femoral head and acetabular articular surfaces.
The postreduction AP and Judet views (B–D) demonstrate a widened joint space compared with the normal side and an incongruent reduction. Note that there are fragments both superior and inferior in the joint and that there is a loss of parallelism of the femoral head and acetabular articular surfaces.
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After plain radiographic evaluation, CT with 2 mm cuts through the hip should be obtained.6,48,71,80,114,124,169,179,186,192,222,230 The CT scan is more sensitive in detecting small intra-articular fragments, femoral head fractures, femoral head impaction injuries, acetabular fractures, and joint incongruity,6,48,59,124,147,192,230 it has been demonstrated that intra-articular fragments are better visualized on CT than plain films. Hougaard et al.80 reported six cases of minor acetabular fractures and six cases of retained intra-articular fragments visualized on CT and not visible on plain radiographs in patients after closed reductions of posterior hip dislocations. In addition, Baird6 and colleagues demonstrated CT to be more sensitive than plain radiographs in identifying 2-mm methyl methacrylate beads placed in cadaveric hips. The congruence of the hip is also easily evaluated using CT. The head should be in the center of the subchondral ring of the acetabulum as it becomes visible, appearing as a bullseye.209 A difference as small as 0.5 mm in the distance from the anterior, articular surface to the femoral head has been reported to indicate a subluxation of the hip.28 Impaction injuries and femoral head fractures are much more easily seen on the postreduction CT. The quality of the reduction of femoral head fractures is also apparent and determines treatment. The CT scan also aids in directing follow-up radiographic analysis in the case of reduced femoral head fractures. Moed and Maxey139 suggested the use of specific angled radiographs based on the CT determination of the fracture direction when obtaining follow-up radiographs of femoral head fractures treated nonoperatively. 
Possibly the most important aspect of the CT scan is in planning operative intervention when necessary in cases of concomitant fracture, irreducible dislocation, or incongruent reduction. The location, size, and number of free intra-articular fragments and the location and size of femoral head fragments are clearly delineated, allowing for accurate planning of operative procedures. Although CT is very sensitive in identifying small, retained fragments, not all intra-articular fragments will affect the treatment plan. 
MRI has shown promise in the evaluation of a traumatic osteonecrosis of the hip.43,154,156,205,209 However, its use in acute dislocations of the hip has not been clearly established. Laorr et al.112 performed MRI examinations of both hips in 18 patients after traumatic dislocation at an average of 13 days postreduction. Trabecular changes were noted in eight (44%) of the hips. However, since no follow-up data are available for these patients, the usefulness of MRI in predicting AVN or arthritis was not established. Additionally MRI changes of AVN may not be present before 6 to 8 weeks (Fig. 48-7). MRI studies can also help define soft tissue injuries following hip dislocations. Tannast et al.205 used MRI following posterior hip dislocation, with the hypothesis that if the obturator externus was ruptured this would be a prognostic indication of AVN, due to the tendons proximity to the femoral head blood supply, the MFCA. In the 19 hips they evaluated all the obturator externus tendons were intact. Although, not able to prove their hypothesis, none of the 19 hips went on to AVN at 3 years of follow-up, suggesting there may be a correlation. Regardless, of its predictive values of AVN in the acute setting, MRI is the optimal study for evaluation of the soft tissues such as the external rotator tendons, the labrum, and cartilage. The traumatized hip from a dislocation will likely have an effusion, which will help identify any abnormalities of the labrum or capsule. Still, the utility of the MRI in the acute setting is unknown and may be better in a delayed fashion if the hip remains persistently symptomatic.33,87,152,205 MRI is also useful in diagnosing insufficiency or impaction injuries from overuse, and appears to be more sensitive than CT in detecting these lesions.27 A typical pattern of low density band with edema and contrast enhancement proximal and distal to the band is seen.213 
The use of single photon emission computed tomography (SPECT) has been shown to aid in distinguishing avascular changes from impaction injuries of the femoral head.56 Despite its usefulness in this differentiation, SPECT has not been helpful in predicting AVN when used in the peri-injury time frame. Yue et al.234 studied 54 dislocations and fracture dislocations pre- and postreduction and then followed the patients for a minimum of 1 year. The average time to reduction of the hip was 4 hours. They found that low blood flow patterns were seen in early and late reductions, but that these patterns did not predict AVN at an average of 24 months. 

Classification of Hip Dislocations and Fractures of the Femoral Head

Several classification schemes have been described for hip dislocations. All of these schemes include subtypes for important associated injuries. The first distinction is whether the hip dislocation is anterior or posterior. Anterior dislocations are described by their anatomic location, being superior, including pubic or subspinous, or inferior, including obturator, thyroid, and perineal locations.2,14,29,30,42,69,185,193,198,224 In anterior dislocations, femoral head impaction injuries are more common than shearing injuries. These are more apparent on the CT images than on plain films. 
Figure 48-7
A 27-year-old woman involved in a waterskiing accident sustained a hip dislocation.
 
Initial MRI demonstrates a posterior capsule avulsion and impaction on the femoral head (A, B). At 3 months post injury her pain increased and osteonecrosis of the femoral head was seen on plain lateral radiograph (C) and on follow-up MRI (D). The patient ultimately underwent a THA and at the time of surgery the femoral head demonstrates a collapse and cleavage of the femoral head cartilage (E).
Initial MRI demonstrates a posterior capsule avulsion and impaction on the femoral head (A, B). At 3 months post injury her pain increased and osteonecrosis of the femoral head was seen on plain lateral radiograph (C) and on follow-up MRI (D). The patient ultimately underwent a THA and at the time of surgery the femoral head demonstrates a collapse and cleavage of the femoral head cartilage (E).
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Initial MRI demonstrates a posterior capsule avulsion and impaction on the femoral head (A, B). At 3 months post injury her pain increased and osteonecrosis of the femoral head was seen on plain lateral radiograph (C) and on follow-up MRI (D). The patient ultimately underwent a THA and at the time of surgery the femoral head demonstrates a collapse and cleavage of the femoral head cartilage (E).
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Figure 48-7
A 27-year-old woman involved in a waterskiing accident sustained a hip dislocation.
Initial MRI demonstrates a posterior capsule avulsion and impaction on the femoral head (A, B). At 3 months post injury her pain increased and osteonecrosis of the femoral head was seen on plain lateral radiograph (C) and on follow-up MRI (D). The patient ultimately underwent a THA and at the time of surgery the femoral head demonstrates a collapse and cleavage of the femoral head cartilage (E).
Initial MRI demonstrates a posterior capsule avulsion and impaction on the femoral head (A, B). At 3 months post injury her pain increased and osteonecrosis of the femoral head was seen on plain lateral radiograph (C) and on follow-up MRI (D). The patient ultimately underwent a THA and at the time of surgery the femoral head demonstrates a collapse and cleavage of the femoral head cartilage (E).
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Initial MRI demonstrates a posterior capsule avulsion and impaction on the femoral head (A, B). At 3 months post injury her pain increased and osteonecrosis of the femoral head was seen on plain lateral radiograph (C) and on follow-up MRI (D). The patient ultimately underwent a THA and at the time of surgery the femoral head demonstrates a collapse and cleavage of the femoral head cartilage (E).
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Posterior dislocations are much more common than anterior dislocations. Two original classification schemes have been described for posterior dislocations. Thompson and Epstein206 and subsequently Stewart and Milford196 both described systems incorporating associated fractures (Table 48-3). The Stewart and Milford scheme specifically addresses postreduction stability in the case of acetabular fracture, which has prognostic implications.82,196 Epstein’s type 5 dislocation includes a femoral head fracture. This type has been subdivided by Pipkin into four types (Table 48-4 and Fig. 48-8).153 This scheme is commonly used and is important in decision making. 
Figure 48-8
The Pipkin Classification of dislocation with femoral head fractures.
 
Type I (A), Type II (B), Type III (C), and Type IV (D).
Type I (A), Type II (B), Type III (C), and Type IV (D).
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Figure 48-8
The Pipkin Classification of dislocation with femoral head fractures.
Type I (A), Type II (B), Type III (C), and Type IV (D).
Type I (A), Type II (B), Type III (C), and Type IV (D).
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Table 48-3
Classification Schemes for Posterior Hip Dislocations
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Table 48-3
Classification Schemes for Posterior Hip Dislocations
Thompson and Epstein
Type I Dislocation with or without minor fracture
Type II Dislocation with single large fracture of the posterior rim of the acetabulum
Type III Dislocation with comminuted fracture of the rim, with or without a large major fragment
Type IV Dislocation with fracture of the acetabular floor
Type V Dislocation with fracture of the femoral head
Stewart and Milford
Type I Simple dislocation without fracture
Type II Dislocation with one or more rim fragments but with sufficient socket to ensure stability after reduction
Type III Dislocation with fracture of the rim producing gross instability
Type IV Dislocation with fracture of the head or neck of the femur
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Table 48-4
Pipkin Classification
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Table 48-4
Pipkin Classification
Type I Posterior dislocation with femoral head fracture caudad to the fovea
Type II Posterior dislocation with femoral head fracture cephalad to the fovea
Type III Femoral head fracture with associated femoral neck fracture
Type IV Type I, II, or III with associated acetabular fracture
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A unified descriptive scheme has been suggested by Brumback et al.19 and can be used for anterior or posterior dislocations (Table 48-5). Brumback’s classification takes into account the size of the head fragment, the direction of the dislocation, as well as the stability of the hip (Fig. 48-9). Finally, the Orthopaedic Trauma Association’s comprehensive fracture classification scheme includes hip dislocations (Fig. 48-10). 
Figure 48-9
The Brumback classification of hip dislocations with femoral head fractures.
 
(Adapted from Stannard JP, Harris HW, Volgas DA, et al. Functional outcome of patients with femoral head fractures associated with hip dislocations. Clin Ortho Rel Res. 2000;377:44–56.)
(Adapted from Stannard JP, Harris HW, Volgas DA, et al. Functional outcome of patients with femoral head fractures associated with hip dislocations. Clin Ortho Rel Res. 2000;377:44–56.)
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Figure 48-9
The Brumback classification of hip dislocations with femoral head fractures.
(Adapted from Stannard JP, Harris HW, Volgas DA, et al. Functional outcome of patients with femoral head fractures associated with hip dislocations. Clin Ortho Rel Res. 2000;377:44–56.)
(Adapted from Stannard JP, Harris HW, Volgas DA, et al. Functional outcome of patients with femoral head fractures associated with hip dislocations. Clin Ortho Rel Res. 2000;377:44–56.)
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Figure 48-10
The Orthopaedic Trauma Association classification of hip dislocations (A) and femoral head fractures (B).
Rockwood-ch048-image010.png
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Table 48-5
Brumback Classification of Femoral Head Fractures
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Table 48-5
Brumback Classification of Femoral Head Fractures
Type Description
Type 1 Posterior hip dislocation with fracture of the femoral head involving the inferomedial portion of the femoral head
Type 1A With minimum or no fracture of the acetabular rim and staple hip joint after reduction
Type 1B With significant acetabular rim and stable joint after reconstruction
Type 2 Posterior hip dislocation with fracture of the femoral head involving the supermedial portion of the femoral head
Type 2A With minimum or no fracture of the acetabular rim and stable joint after reduction
Type 2B With significant acetabular fracture and hip joint instability
Type 3 Dislocation of the hip (unspecified direction) with femoral neck fracture
Type 3A Without fracture of the femoral head
Type 3B With fracture of the femoral head
Type 4 Anterior dislocation of the femoral head
Type 4A Indentation type: Depression of the superolateral surface of the femoral head
Type 4B Transchondral type; osteocartilaginous shear fracture of the weight-bearing surface of the femoral head
Type 5 Central fracture–dislocation of the hip with femoral head fracture
 

From Stannard JP, Harris HW, Volgas DA, et al. Functional outcome of patients with femoral head fractures associated with hip dislocations. Clin Orthop Rel Res. 2000;377:44–56.

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Regardless of the scheme used, the important elements are whether there is an associated fracture and whether the hip is stable after reduction. In each scheme, the presence of an acetabular fracture requiring reduction and fixation is noted. For the purpose of this text, these injuries are considered to be acetabular fractures and are discussed in Chapter 47. This chapter focuses on pure dislocations that are stable after reduction (whether that be open or closed) and those with associated femoral head fractures. 

Outcomes Scores used for Hip Dislocations and Fractures of the Femoral Head

Assessment of patient outcome following hip dislocation or fracture–dislocations revolves around patients’ function and pain. Osteonecrosis and arthritis are the two main limiting factors for patient outcomes, hence to evaluate the patients’ outcome using standardized hip scores such as Harris Hip score, WOMAC, and Merle d’aubane are most commonly reported. These provide clinicians insight into how their hip is functioning and combined with overall health scores such as SMFA and SF12 scores are also used. 

Pathoanatomy and Applied Antatomy Related to Hip Dislocations and Fractures of the Femoral Head

Pathoanatomy

For the hip to dislocate, the ligamentum teres and at least a portion of the capsule must be disrupted. Labral tears or avulsions and muscular injury are common.112 Pringle and Edwards157 examined the soft tissue injuries in cadavers in which they induced hip dislocations. They found that the capsule may be stripped as a cuff from either the acetabulum or femur by a rotational force or be split by direct pressure. A combination of these capsular injuries may take place resulting in an L-shaped lesion. 
In posterior dislocations, the capsule is torn either directly posteriorly or inferoposteriorly depending on the amount of flexion at the time of the injury. The Y ligament is generally intact with the capsule stripped from its acetabular attachment posterior to it. However, in some cases, the Y ligament may be avulsed with a fragment of bone.20 
In anterior dislocations, the psoas acts as the fulcrum of the hip, and the capsule is disrupted anteriorly and inferiorly. Although rare, in extremely high-energy injuries, the femoral vessels can be injured or an open hip dislocation can occur.109 
Femoral head injury is common and may be the result of a shearing injury, impaction, or avulsion.40 Avulsions are most common. When the hip dislocates, a small fragment remains attached to the ligamentum teres, avulsing from the head. These fragments, if small and within the fovea, are of minimal concern. More severe injuries to the head involve a shearing mechanism or impaction injury. Impaction is more common after anterior dislocation and may be quite large, similar to a Hill–Sachs lesion.40 Anterior dislocations with this pattern can be at a higher risk of AVN because the impaction occurs the point were the MFCA vessels insert into the head, the posterior superior portion of the head–neck junction. 
Shear injuries are usually the result of a posterior dislocation that occurs with less adduction and internal rotation, forcing the head against the rim of the posterior wall. In these cases, the head fails in shear rather than the posterior wall fracturing. Because of the mechanism, the fracture fragment is sheared from the anteromedial head, with the fracture line running from anterolateral to posteromedial (Fig. 48-11). These head fragments may be attached to the ligamentum teres and remain in a relatively normal position or can be free of soft tissue attachments within the joint. 
Figure 48-11
 
The fracture line of the femoral head is typically 25 to 45 degrees off the coronal axis with the free fragment located anteromedially.
The fracture line of the femoral head is typically 25 to 45 degrees off the coronal axis with the free fragment located anteromedially.
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Figure 48-11
The fracture line of the femoral head is typically 25 to 45 degrees off the coronal axis with the free fragment located anteromedially.
The fracture line of the femoral head is typically 25 to 45 degrees off the coronal axis with the free fragment located anteromedially.
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Free intra-articular fragments can also be generated from comminution of associated fractures, shearing of cartilage, and extra-articular fragments being pulled into the joint during the reduction. 

Biomechanics

The hip functions as a ball-and-socket joint, allowing a wide range of motion while remaining well constrained. Much of the stability of the hip is derived from its role as the fulcrum about which the large muscles that surround it act. These muscular actions tend to force the femoral head into the acetabulum, taking advantage of its depth. The capsule is loose compared to other joints allowing for greater motion in multiple directions. 
The acetabulum opens facing obliquely anteriorly and inferiorly. The articular cartilage, which resembles a horseshoe, is thickest laterally and peripherally.97,166 This coincides with descriptions of the loading pattern of the acetabulum as being primarily peripheral.146 
The femoral head forms approximately two-thirds of a complete sphere.62 The articular cartilage of the head is thickest on the medial and central surfaces. The position that the head takes within the acetabulum is affected by the anteversion of the femoral neck on the shaft, where normal is 12 degrees and by the neck-shaft angle, which averages 125 degrees.62 The neck-shaft angle allows for freedom of motion by providing offset of the femur from the pelvis. Variation in the neck-shaft angle is common, and can affect the loading pattern of the hip. Likewise, deviation in anteversion affects the position of the head within the acetabulum. 
The forces through the hip vary greatly during even simple activities and are caused primarily by the force of the muscles acting about the joint. During double leg stance, because few muscles are necessary for balance, the joint reaction force is approximately one-third of body weight. This is in contradistinction to normal gait, where the joint reaction force can reach six times body weight. With respect to the rehabilitation of patients with hip joint injury, it is important to note that due to the weight of the leg, the joint reaction force on the hip in swing phase can be greater than body weight.62 Of equal importance to the hospitalized or injured patient is that the act of getting on a bedpan can generate more than two times body weight through the joint. The least force through the hip is with toe touch or foot flat partial weight bearing, which allows the ground to support the weight of the leg rather than the hip musculature. The biomechanics of hip dislocation include the factors of force of injury, native hip anatomy such as anteversion, and the position of the hip at impact. Less anteversion and a position of internal rotation at impact favor pure dislocation over fracture dislocation. This topic was more completely reviewed above (see “Biomechanics” section). 

Surgical and Applied Anatomy

Ligamentous Anatomy

The hip joint is a constrained ball-and-socket joint. The head rotates within the acetabulum and is incompletely covered. The depth of the acetabulum is supplemented by the fibrous labrum, which makes the joint functionally deeper and more stable (Fig. 48-12). The labrum adds more than 10% to the coverage of the femoral head, creating a situation that keeps the head more than 50% covered during motion.15,78,79,143,165 It takes more than 400 N of force just to distract the hip joint.59 The capsule of the hip is strong and extends from the rim of the acetabulum to the intertrochanteric line anteriorly and the femoral neck posteriorly. The longitudinal fibers are supported by spiral capsular thickenings called ligaments. Anteriorly, the iliofemoral or Y ligament originates from the superior aspect of the joint at the ilium and anterior inferior iliac spine. It runs in two bands inserting along the intertrochanteric line superiorly and just superior to the lesser trochanter inferiorly. The inferior capsule is further supported by the pubofemoral ligament, which takes its origin from the superolateral superior ramus and inserts on the intertrochanteric line deep to the Y ligament (Fig. 48-13).78,136 
Figure 48-12
Coronal section of the hip of a child demonstrates the added depth that the labrum provides over the femoral head.
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Figure 48-13
The hip capsule and its thickenings (ligaments as visualized from anteriorly (A) and posteriorly (B)).
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Posteriorly, the capsule inserts on the femoral neck just inferior to the head medially and extends to the base of the greater trochanter laterally. The ischiofemoral ligament within the capsule posteriorly originates at the junction of the inferior posterior wall with the ischium. It runs obliquely lateral and superior to insert on the femoral neck with the capsule (Fig 48-13).78,136 In addition to these ligaments, the short external rotators lie on the posterior capsule, providing additional support. 

Neurovascular Anatomy

All the nerves to the lower extremity pass close to the hip joint. The sciatic nerve warrants the most attention, as it is most at risk. This nerve runs posteriorly to the joint, emerging from the greater sciatic notch deep to the piriformis and superficial to the obturator internis and gemelli muscles. In 85% of people, the nerve is a singular structure located in the normal position. In 12%, it divides before exiting the greater sciatic notch, and the peroneal division passes through, rather than deep to, the piriformis muscle. In 3%, the nerve divisions surround the piriformis, and in 1%, the entire nerve passes through the piriformis11 (Fig. 48-14). With posterior dislocation, the nerve may be stretched or directly compressed. 
Figure 48-14
(A) The sciatic nerve is a single structure that emerges from the greater sciatic notch anterior to the piriformis in 84% of cases.
 
(B, C, D) In 16 % a portion of the nerve passes through the piriformis or posterior to it, placing it a great risk.
(B, C, D) In 16 % a portion of the nerve passes through the piriformis or posterior to it, placing it a great risk.
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Figure 48-14
(A) The sciatic nerve is a single structure that emerges from the greater sciatic notch anterior to the piriformis in 84% of cases.
(B, C, D) In 16 % a portion of the nerve passes through the piriformis or posterior to it, placing it a great risk.
(B, C, D) In 16 % a portion of the nerve passes through the piriformis or posterior to it, placing it a great risk.
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The obturator nerve passes through the superolateral obturator foramen with the obturator artery. The femoral nerve lies medial to the psoas in the same sheath and can be injured with anterior dislocation. 
Injury to the vascular supply of the femoral head is an important factor in hip dislocations. In adults, the primary blood supply to the head derives from the cervical arteries. These arteries originate from the extracapsular ring at the base of the femoral neck (Fig. 48-15). This ring is formed by contributions from the medial femoral circumflex artery (MFCA) posteriorly and the lateral femoral circumflex anteriorly.84 The capital vessels traverse the capsule close to its insertion on the neck and the trochanteric ridge and ascend parallel to the neck, entering the head adjacent to the inferior articular surface.35,73,78 The superior and posterior vessels, which are derived primarily from the MFCA, have been shown to be the dominant blood supply to the femoral head.67,70,90 In addition, the MFCA supplies the inferior retinacular branch that runs along the ligament of Weitbrecht and supplies the inferior medial portion of the femoral head.67,70,90 In addition to the cervical vessels, a minor contribution to the head arises from the foveal artery, a branch of the obturator artery that lies within the ligamentum teres. This artery makes a significant contribution to the epiphyseal portion of the femoral head vasculature in approximately 75% of hips.39 
Figure 48-15
The vascular supply to the femoral head arises from the medial and lateral circumflex vessels, which create a ring, giving rise to the cervical vessels.
 
A minor contribution comes from the obturator artery via the ligamentum teres.
 
(Modified from Gardner MJ, Suk M, Pearle A, et al. Surgical dislocation of the hip for fractures of the femoral head. J Ortho Trauma. 2005;19:336.)
A minor contribution comes from the obturator artery via the ligamentum teres.
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Figure 48-15
The vascular supply to the femoral head arises from the medial and lateral circumflex vessels, which create a ring, giving rise to the cervical vessels.
A minor contribution comes from the obturator artery via the ligamentum teres.
(Modified from Gardner MJ, Suk M, Pearle A, et al. Surgical dislocation of the hip for fractures of the femoral head. J Ortho Trauma. 2005;19:336.)
A minor contribution comes from the obturator artery via the ligamentum teres.
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The position of the hip when dislocated can kink the vessels supplying the head, making the collateral circulation important. Yue et al.235 did injection studies of six cadaveric hips after forceful dislocation and relocation. Filling defects were demonstrated at the junction of the external iliac and common femoral arteries and at the circumflex vessels as compared with the normal hip. However, this change in the extraosseous blood supply did not provide a consistent change in the intraosseous supply to the head, presumably due to collateral circulation. 

Treatment Options for Hip Dislocations and Fractures of the Femoral Head

Nonoperative Treatment of Hip Dislocations and Fractures of the Femoral Head

Indications/Contraindications

The initial management for almost all hip dislocations is an attempt at a closed reduction. The reduction should be considered an emergent procedure and includes patients with concomitant femoral head fractures or acetabular fractures.17,80,85,105,110,119,158,195,207 Contraindication to standard closed reduction are, nondisplaced femoral neck fractures and other associated injuries that preclude using the lower extremity to manipulate the hip. Nondisplaced femoral neck fractures should be treated with caution. In general percutaneous fixation with screws should be performed before attempting a closed reduction to prevent displacement of femoral neck fracture. For dislocations without associated fractures that result in a congruent reduction by closed means, nonoperative management is usually definitive (Table 48-6). However, irreducible dislocations, those with incongruent reductions, and those with associated fractures may require subsequent operative management. 
Table 48-6
Indications for Nonoperative Hip Dislocations and Femoral Head Fractures
Hip Dislocations and Femoral Head Fractures
Nonoperative Treatment
Indications Relative Contraindications
Pure dislocation Pipkin III and IV
Pipkin I Incongruent reduction
Pipkin II Loose bodies interfere with joint
Congruent joint postreduction
+/– small fragment in funda
Femoral Neck fractures (nondisplaced)
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After appropriate workup as previously described, an attempt at closed reduction should be performed. This is typically performed in the operating room, but can be performed in the emergency department if the patient is already intubated. Regardless of the direction of the dislocation, the reduction is attempted by traction in line with the femur and gentle rotation. An Allis1 maneuver is tried next if the dislocation is posterior, and the Walker modification of the Allis1 technique if the dislocation is anterior. If the hip is irreducible, then immediate open reduction is necessary. If the closed reduction is successful, then postreduction studies including AP and Judet views of the hip and a CT with 2-mm cuts are obtained to determine the congruence of the reduction and the postreduction position of any associated fractures. If there is no associated fracture and the hip is congruent with symmetric joint space to the contralateral hip on all plain films and the CT scan, then nonoperative management is definitive. A short period of protected weight bearing is all that is necessary (see “Postoperative Care”). 
In the early postoperative period, patients may experience groin pain or mechanical symptoms. These should be worked up with MRI and may be considered for operative management with hip arthroscopy.33,205 After the reduction by any of the described methods is obtained, a full set of radiographs and 2-mm CT through the hip should be obtained. These studies determine if the reduction is congruous. If the hip is congruous and there are no associated fractures of the acetabulum or femoral head that require surgery, then nonoperative management is generally definitive. This is the case even if there are small fragments of bone retained of the hip joint (Fig. 48-16). Small fragments do not require debridement, as long as there are no fragments making contact with the articular surface of the head during movement and the fragments are not between the articular surfaces of the head and acetabulum. (Fig. 48-17). These bony fragments are attached to the ligamentum teres and are not free to move within the joint (Table 48-6). 
Figure 48-16
AP radiograph of a 24-year-old man after closed reduction of a posterior hip dislocation with associated inferior femoral head fracture (Pipkin type1).
 
The femoral head fracture is displaced, but is not impinging on the reduction of the hip, which is concentric (A). The CT scan confirms that the reduction of the hip is concentric (B) and shows the femoral head fragment to be located inferiorly (C). The fragment was left in place and the patient was treated nonoperatively.
The femoral head fracture is displaced, but is not impinging on the reduction of the hip, which is concentric (A). The CT scan confirms that the reduction of the hip is concentric (B) and shows the femoral head fragment to be located inferiorly (C). The fragment was left in place and the patient was treated nonoperatively.
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Figure 48-16
AP radiograph of a 24-year-old man after closed reduction of a posterior hip dislocation with associated inferior femoral head fracture (Pipkin type1).
The femoral head fracture is displaced, but is not impinging on the reduction of the hip, which is concentric (A). The CT scan confirms that the reduction of the hip is concentric (B) and shows the femoral head fragment to be located inferiorly (C). The fragment was left in place and the patient was treated nonoperatively.
The femoral head fracture is displaced, but is not impinging on the reduction of the hip, which is concentric (A). The CT scan confirms that the reduction of the hip is concentric (B) and shows the femoral head fragment to be located inferiorly (C). The fragment was left in place and the patient was treated nonoperatively.
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Figure 48-17
The postreduction CT of a patient after posterior dislocation demonstrates a small, insignificant fragment in the fovea centralis, which does not affect the congruous hip reduction and does not require removal.
 
Fragments are considered insignificant if they clearly do not impinge on the head (A). As opposed to a large fragment incarcerated between the femoral head and the posterior wall which will require surgical removal (B).
Fragments are considered insignificant if they clearly do not impinge on the head (A). As opposed to a large fragment incarcerated between the femoral head and the posterior wall which will require surgical removal (B).
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Figure 48-17
The postreduction CT of a patient after posterior dislocation demonstrates a small, insignificant fragment in the fovea centralis, which does not affect the congruous hip reduction and does not require removal.
Fragments are considered insignificant if they clearly do not impinge on the head (A). As opposed to a large fragment incarcerated between the femoral head and the posterior wall which will require surgical removal (B).
Fragments are considered insignificant if they clearly do not impinge on the head (A). As opposed to a large fragment incarcerated between the femoral head and the posterior wall which will require surgical removal (B).
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Techniques for Closed Reduction

Posterior Dislocation.
The patient must be completely relaxed, regardless of the technique used, to close reduce the hip. If the patient is already intubated due to other injuries, then the reduction may take place in the emergency department with proper monitoring after paralytic agents are given. In most circumstances, the reduction should be performed in the operating room unless one is not available. This creates the safest environment to control the patient’s airway and provide complete muscle paralysis. In rare circumstances, the reduction may need to be performed in the emergency department under conscious sedation. It is best to have an emergency physician or anesthesiologist present to control the airway during the procedure and to monitor the patient’s oxygenation. Although not uniformly agreed upon, most authors believe that no more than two closed reduction attempts should be made to avoid further damage to the femoral head.17,40,53,195,218 Another advantage of performing the reduction in the operating room is the use of real time fluoroscopy to aid in the reduction. The position of the head with respect to the acetabulum can be visualized well if there is difficulty reducing the hip, and adjustments based on the position can be made. It also allows for a thorough evaluation of hip stability or if warranted a stress exam following reduction. 
The Allis Maneuver.
The Allis1 maneuver is appropriate even in the face of other traumatic injuries. It is performed with the patient in the supine position and uses the familiar traction and counter-traction techniques that are used to reduce other joints. The patient is placed supine on a stable table. The assistant stabilizes the pelvis, usually by pushing down on the anterior superior iliac spine while pushing laterally on the inner proximal thigh. The surgeon then flexes the knee and the hip to relax the hamstrings. Steady longitudinal traction is then applied with the extremity in internal rotation and adduction. While the traction is being applied, the leg is gently rotated, allowing the reduction (Fig. 48-18). Several modifications of this technique have been described. The “East Baltimore Lift” utilizes several assistants in an attempt to make the reduction less demanding on the surgeon.171 Performing the reduction in the lateral position has been suggested to diminish the risk of lower back injury to the surgeon.36 
Figure 48-18
The Allis1 reduction technique for posterior hip dislocations.
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Figure 48-18
The Allis1 reduction technique for posterior hip dislocations.
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Regardless of the technique used to reduce a posterior dislocation, after the reduction is accomplished the hip is extended and externally rotated and a knee immobilizer is placed on the leg. These measures will maintain the hip reduced while postreduction studies are obtained. 
Technique for Anterior Dislocations.
Anterior dislocations are also reduced using traction and counter-traction. For inferior dislocations, Walker 223 described a modification of the Allis1 technique. Traction is continuously applied in line with the femur with gentle flexion. Along with a lateral push on the inner thigh, internal rotation and adduction are used to reduce the hip (Fig. 48-19). If the dislocation is superior, then distal traction is applied until the head is at the level of the acetabulum and gentle internal rotation is applied. Extension may be necessary when reducing anterior dislocations.42 
Figure 48-19
The Allis1 maneuver for anterior hip dislocations.
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Figure 48-19
The Allis1 maneuver for anterior hip dislocations.
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For all types of reduction, the surgeon should use continuous traction rather than short jerky motions. By using continuous distraction and gentle manipulation, the reduction is achieved while minimizing additional trauma. Sudden forceful movements can cause fractures of the neck and damage the articular surface of the femoral head.155,209 
Fluoroscopic Evaluation of the Hip following Closed Reduction.
Definitive nonoperative management is also indicated if fractures exist that do not require fixation or cause instability of the hip. Two types of injury fall into this category: Pipkin type I femoral head fractures, which do not create incongruity, and small posterior wall fractures that do not allow for instability. The amount of posterior wall that can be affected without causing instability is debated. If greater than 35% of the posterior wall is affected, the loading pattern of the hip is altered and may lead to arthritis.146 On the basis of cadaveric studies, most authors would recommend ORIF of these fractures. A more complete discussion of this topic and techniques of fixation are included in Chapter 47 (Acetabular Fractures). For the purpose of this discussion, we will consider only posterior wall fragments that do not necessarily require reduction and fixation based on their size. If the posterior wall fragment is small enough that fixation may not be required, stability testing can be performed to ensure that the hip is stable.209 
In the face of an associated posterior wall fracture, if the hip reduction is incongruent, then an open reduction of the hip is necessary with removal of debris as described above. The posterior wall is fixed at the same time through the same incision. If the hip is congruently reduced and the posterior wall is fractured, then the next question is whether the posterior wall should be fixed. While the techniques for fixation of posterior wall fractures are covered elsewhere in this text (Chapter 47), the determination of which fractures should be fixed and which may be treated nonoperatively must be understood. This is a controversial question and there is no definitive answer. Olson et al.146 have demonstrated that a posterior wall articular defect as small as 27% leads to an alteration in the joint contact forces. Likewise, they demonstrated that the largest change in the contact forces occurs with any posterior wall fracture as compared with the intact acetabulum and that the size of the wall fragment is less important. Although not clearly demonstrated in any clinical series, in theory posterior wall fractures that affect the joint mechanics and increase the contact forces in the roof may lead to arthritis. Based on these findings and the low morbidity secondary to advances made in acetabular fracture fixation, posterior wall fractures that affect greater than 30% of the posterior articular surface are generally fixed. 
More important is the significant problem of joint wear if the hip is unstable. Hougaard and Thomsen82 reported that 83% of patients with posterior wall fractures allowing for instability of the hip went on to arthritis if treated nonoperatively. Hips with posterior wall fractures that allowed for instability that were reduced and fixed developed arthritis at a rate similar to dislocations without associated fractures.43,81 These hips represent the Stewart and Milford type III injury. Thus, determination of instability in the face of posterior wall fractures with hip dislocations is paramount. The authors believe that any posterior wall fracture that allows for hip instability should be fixed regardless of the size. Several authors have examined the relationship of posterior wall fragment size and instability and made distinct recommendations.28,94,219 In all of these studies, specific sizes of posterior wall fractures were found to be unstable, but a large ambiguous zone is also reported. The soft tissue injury associated with the fracture is thought to cause this ambiguity and cannot be assessed directly by plain radiography or CT scanning. 
Based on the inconsistency of these studies, the significant ambiguity, and the importance of hip stability to long-term outcome, the author utilizes a fluoroscopic stress examination to determine hip stability in all posterior wall fractures that do not require fixation on the basis of fragment size.208 This is performed with the patient under general anesthesia in the operating room on a radiolucent table. With the patient asleep or sedated, the hip is brought through a range of motion under fluoroscopy. The hip is flexed and internally rotated and enough pressure to rock the pelvis is applied in line with the femur in an attempt to displace the head posteriorly. This stress test is repeated in the AP and obturator oblique positions. The hip is brought through a range of motion under fluoroscopy (Fig. 48-20). Any change in the congruous relationship of the head to the roof indicates posterior subluxation, and the hip should be considered unstable (Stewart and Milford type III) (Fig. 48-21). In a small series, Tornetta208 reported a fragment consisting of only 15% of the posterior wall caused instability. If the hip is found to be stable, then nonoperative management may be chosen as definitive. 
Figure 48-20
Method of performing fluoroscopic stress view in the operating room for a posterior wall fracture.
 
The photograph depicts the obturator oblique view with the image intensifier at a 45-degree angle to the body.
The photograph depicts the obturator oblique view with the image intensifier at a 45-degree angle to the body.
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Figure 48-20
Method of performing fluoroscopic stress view in the operating room for a posterior wall fracture.
The photograph depicts the obturator oblique view with the image intensifier at a 45-degree angle to the body.
The photograph depicts the obturator oblique view with the image intensifier at a 45-degree angle to the body.
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Figure 48-21
The obturator Oblique view of a patient after closed reduction of a posterior wall fracture (A).
 
In the operating room with the patient asleep, the AP view of the hip demonstrates a congruent relationship of the head to the roof (B). With flexion of the hip, the head subluxes away from the roof (arrows) and becomes incongruous, indicating instability (C). The posterior subluxation is also evident on the obturator oblique view (D, E).
In the operating room with the patient asleep, the AP view of the hip demonstrates a congruent relationship of the head to the roof (B). With flexion of the hip, the head subluxes away from the roof (arrows) and becomes incongruous, indicating instability (C). The posterior subluxation is also evident on the obturator oblique view (D, E).
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Figure 48-21
The obturator Oblique view of a patient after closed reduction of a posterior wall fracture (A).
In the operating room with the patient asleep, the AP view of the hip demonstrates a congruent relationship of the head to the roof (B). With flexion of the hip, the head subluxes away from the roof (arrows) and becomes incongruous, indicating instability (C). The posterior subluxation is also evident on the obturator oblique view (D, E).
In the operating room with the patient asleep, the AP view of the hip demonstrates a congruent relationship of the head to the roof (B). With flexion of the hip, the head subluxes away from the roof (arrows) and becomes incongruous, indicating instability (C). The posterior subluxation is also evident on the obturator oblique view (D, E).
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If instability exists typically, the posterior wall fragment is attached to the labrum (Fig. 48-22). Repair of the labrum and the open reduction of the posterior wall fragment is then performed, either through a surgical dislocation if a femoral head fracture is involved or through a Kocher-Langenbeck approach (Fig. 48-23) if it is an isolated posterior wall fragment. If the hip is shown to be stable, then nonoperative management is prescribed as in patients without associated posterior wall fractures. 
Figure 48-22
Image is a picture of a typical small posterior wall fragment combined with a labral tear after fracture dislocation, Pipkin type IV.
 
The labrum is still attached to the acetabulum superiorly. The posterior wall fragment (P.W. outlined with dashed line) is attached to the labrum and the labrum is detached inferiorly exposing the fracture bed (blue arrows) (A). The posterior wall fragment is reduced with the labrum repaired with suture anchors and the fragment can be held with an antiglide plate (B).
The labrum is still attached to the acetabulum superiorly. The posterior wall fragment (P.W. outlined with dashed line) is attached to the labrum and the labrum is detached inferiorly exposing the fracture bed (blue arrows) (A). The posterior wall fragment is reduced with the labrum repaired with suture anchors and the fragment can be held with an antiglide plate (B).
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Figure 48-22
Image is a picture of a typical small posterior wall fragment combined with a labral tear after fracture dislocation, Pipkin type IV.
The labrum is still attached to the acetabulum superiorly. The posterior wall fragment (P.W. outlined with dashed line) is attached to the labrum and the labrum is detached inferiorly exposing the fracture bed (blue arrows) (A). The posterior wall fragment is reduced with the labrum repaired with suture anchors and the fragment can be held with an antiglide plate (B).
The labrum is still attached to the acetabulum superiorly. The posterior wall fragment (P.W. outlined with dashed line) is attached to the labrum and the labrum is detached inferiorly exposing the fracture bed (blue arrows) (A). The posterior wall fragment is reduced with the labrum repaired with suture anchors and the fragment can be held with an antiglide plate (B).
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Figure 48-23
Postoperative radiograph of the patient in Figure 48-19.
 
After ORIF of the small posterior wall fragment the hip was stable after fixation.
After ORIF of the small posterior wall fragment the hip was stable after fixation.
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Figure 48-23
Postoperative radiograph of the patient in Figure 48-19.
After ORIF of the small posterior wall fragment the hip was stable after fixation.
After ORIF of the small posterior wall fragment the hip was stable after fixation.
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Hip dislocations with small inferior femoral head fractures may also be treated nonoperatively. In cases of inferior femoral head fractures (Pipkin type I), the fracture fragment does not affect the weight-bearing surface. These fracture fragments are not loaded during normal gait and therefore may be treated as loose bodies.81,153,194 If the fragments are well reduced or in a position that does not create an incongruent reduction of the hip, they can be left in place. Thus, fixation or excision is not necessary if the reduction of the hip is congruent. These injuries may be treated with the same nonoperative protocol as a pure hip dislocation. 

Outcomes

Disparate results after simple hip dislocations have been reported. Good-to-excellent results have been demonstrated in 48% to 95% of patients (Table 48-7).43,85 At least part of this variation is due to the types of dislocation reported, the length of follow-up in the various studies, and the criteria used for assessing them. Upadhyay et al.216 and Hougaard and Thomsen82 found increasing rates of arthritis with longer follow-up. In most series, a good result indicated no limp or limp only after a long workday, no more than 25% restriction of motion, no interference with activities of daily living, and no radiographic evidence of arthritis or AVN. Although only small numbers of patients have been studied, it appears that anterior dislocations without femoral head injury fare better than posterior dislocations.2,40,45 Dreinhofer et al.43 reported 75% acceptable results after anterior dislocation and only 48% after posterior dislocation. Vecsei et al.220 reported 87 dislocations in 82 patients. Of 43 patients followed for between 6 months and 19 years, 17 (40%) developed arthritis, but only one had AVN. All dislocations were reduced within 6 hours. Of the 29 otherwise healthy patients, 8 had occasional pain and another 6 had limited motion and pain. 
 
Table 48-7
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Table 48-7
Outcome after Closed Reduction*
Author Year G/E AVN OA
Armstrong3 1948 76% 2% 13%
Thompson and Epstein206 1951 67% 10% 7%
Paus151 1951 71% 2% 20%
Stewart and Milford196 1954 57% 19% 48%
Morton141 1959 76% ** **
Brav17 1962 77% 22% 26%
Hunter85 1969 95% 4% **
Reigstad163 1980 83% 3% 3%
Upadhyay214 1981 75% ** 24%
Hougaard80 1987 87% 5% 31%
Yang231 (anterior) 1991 83% ** **
Yang231 (posterior) 1991 87% ** 19%
Schlickewei173 1993 94% 0% 10%
Dreinhofer43 (anterior) 1994 75% 0% 11%
Dreinhofer43 (posterior) 1994 48% 19% 26%
Vecsei220 1997 79% 3% 40%
 

AVN, avascular necrosis; G/E, good and excellent results; OA, osteoarthritis.

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Significant associated injuries may have a negative impact on results. Both Yang et al.231 and Dreinhofer et al.43 reported poorer results in patients with multiple severe injuries as compared with isolated hip dislocations. Pape et al.149 found high rates of complications in patients with an injury severity score of greater than 18, including 5/17 with early arthritis and 7/17 with AVN. In addition, 64% developed HO, which did not appear to correlate with open procedures. Patients who performed heavy labor may also be at increased risk of poor outcome.216 Likewise, associated fractures may adversely affect outcome. Fracture–dislocations had a poorer prognosis than pure hip dislocation.203 
Results appear to vary most with the time to reduction of the dislocation17,82,141,151,196,217; the longer delay between dislocation and reduction, the worse the outcome. Brav17 reported that reduction after 12 hours raised the rate of unsatisfactory results from 22% to 52%. Stewart and Milford196 reported 88% good results if the dislocation was reduced within 12 hours, and Morton141 found that excellent results occurred only in hips reduced within 12 hours. Reigstad163 found no cases of arthritis or AVN in simple dislocations reduced within 6 hours. In addition, there may be an association of sciatic nerve injury with delays in reduction of the hip in patients transferred to a major center after dislocation.77 

Operative Treatment of Hip Dislocations and Fractures of the Femoral Head

Indications/Contraindications

Operative management is required when the hip is irreducible, there is an incongruent reduction, injury to the sciatic nerve following an attempted reduction, and in some cases of fracture–dislocation. Indications for operative treatment can be broken down to two treatment groups: (1) open reduction with or without debridement and (2) open reduction and internal fixation. The hip is approached from the direction of the dislocation, posterior for posterior dislocation via a Kocher–Langenbeck approach, and anterior for an anterior dislocation via a Smith-Petersen or Watson-Jones approach. If open reduction is necessary, then joint debridement and treatment of all associated fractures are performed simultaneously. This includes ORIF of the acetabular wall or type II femoral head fractures and removal of joint debris or type I femoral head fracture allowing for a congruent reduction. It should be noted that if ORIF is anticipated or an associated acetabular fracture is present a surgical dislocation is the preferred approach. 
If the hip is within the acetabulum, but the reduction is incongruent, then the offending structure needs to be removed, which can be done arthroscopically or in an open fashion. If there are small fragments, an arthroscopic approach is preferred, if there are large fragments then a surgical dislocation is preferred (Fig. 48-24). The postreduction radiographs and particularly the CT will demonstrate any bony fragment interfering with the reduction. Careful analysis of the CT is imperative in planning surgery to remove the fragments. During surgery it is difficult to determine whether the joint is completely free of fragments, so knowledge of the number, location, and size of bony fragments makes the procedure much easier. Other than joint debridement, no specific stabilization of the joint is necessary at this time (Fig. 48-25). However, if the labrum is avulsed from the acetabular rim, repair via suture anchors to a freshened cancellous surface may provide improved stability (Fig. 48-26). After the procedure, the treatment is the same as after successful closed reduction. 
Figure 48-24
This is an image depicting large free fragment in the acetabulum that was removed through a surgical dislocation (A).
 
The piece appeared to come from the posterior inferior acetabulum after an obturator dislocation (B).
The piece appeared to come from the posterior inferior acetabulum after an obturator dislocation (B).
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Figure 48-24
This is an image depicting large free fragment in the acetabulum that was removed through a surgical dislocation (A).
The piece appeared to come from the posterior inferior acetabulum after an obturator dislocation (B).
The piece appeared to come from the posterior inferior acetabulum after an obturator dislocation (B).
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Figure 48-25
AP radiograph of a posterior hip dislocation with a small inferior femoral head fragment (A).
 
Postreduction AP (B) and CT (C) demonstrate that the joint is incongruently reduced and the joint space is widened due to the impingement of the Pipkin I fracture. The fragment was excised and joint debrided. The patient has an excellent result at 4 years (D).
Postreduction AP (B) and CT (C) demonstrate that the joint is incongruently reduced and the joint space is widened due to the impingement of the Pipkin I fracture. The fragment was excised and joint debrided. The patient has an excellent result at 4 years (D).
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Figure 48-25
AP radiograph of a posterior hip dislocation with a small inferior femoral head fragment (A).
Postreduction AP (B) and CT (C) demonstrate that the joint is incongruently reduced and the joint space is widened due to the impingement of the Pipkin I fracture. The fragment was excised and joint debrided. The patient has an excellent result at 4 years (D).
Postreduction AP (B) and CT (C) demonstrate that the joint is incongruently reduced and the joint space is widened due to the impingement of the Pipkin I fracture. The fragment was excised and joint debrided. The patient has an excellent result at 4 years (D).
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Figure 48-26
If open reduction of the hip is necessary, then avulsed labral tears can be repaired using suture anchors after freshening the cancellous bed (A, B).
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Open Reduction with or without Debridement

Open reduction with debridement of the joint and fragment removal may be necessary in several situations (Table 48-8). The indications for open reduction are an irreducible dislocation, sciatic nerve injury caused by a reduction attempt, and cases of incongruent reduction. 
 
Table 48-8
Patterns Treated with Open Reduction and Debridement
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Table 48-8
Patterns Treated with Open Reduction and Debridement
Irreducible dislocation
Iatrogenic sciatic nerve injury
Incongruent reduction with incarcerated fragments
Incongruent reduction with soft tissue interposition
Incongruent reduction with Pipkin type I & II femoral head fracture
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Irreducible dislocations require emergent open reduction. Approximately 2% to 15% of dislocated hips are irreducible via closed means.39 The offending structure may be a bony impingement or soft tissue interposition (Table 48-9). Anterior dislocations are associated with interposition of the rectus femoris, the iliopsoas, the anterior hip capsule, or the labrum.55,75,89,92,122,123,228 Buttonholing though the capsule and bony impingement in the obturator foramen have also been reported.170,209 In posterior dislocations, the causes of irreducibilityare buttonholing though the posterior capsule, and interposition of the piriformis, gluteus maximus, ligamentum teres, labrum, or large bone fragments.20,30,37,85,99,145,150,184 Metha et al.135 reported on irreducible fracture–dislocations of femoral head without a fracture of the posterior acetabular wall and reported this occurred in about 10% of femoral head fracture–dislocations. In all cases, the displaced proximal femur had herniated through a posterior–superior traumatic interval between the acetabular rim and the labrum.135 
 
Table 48-9
Causes of Irreducible Dislocation
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Table 48-9
Causes of Irreducible Dislocation
Anterior
Buttonholing through the capsule
Rectus femoris
Capsule
Labrum
Psoas tendon
Posterior
Piriformis tendon
Gluteus maximus
Capsule
Ligamentum teres
Posterior wall
Bony fragment
Iliofemoral ligament
Labrum
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A CT with 2-mm cuts through the acetabulum is helpful in identifying the offending structure and planning the surgery. If well coordinated, the additional CT cuts can be done during the trauma CT scan and not require a second examination. A full series of radiographs and the fine-cut CT are desirable before performing the open reduction; however, substantial delays should not be accepted. If the reduction of the hip will be significantly delayed by obtaining the CT scan, then it can be deferred until after the open reduction is performed. 
In contradistinction to an irreducible hip dislocation, a nonconcentric reduction is not an emergency. The head is contained within the acetabulum and the blood supply to the head is restored as long as it has not thrombosed or torn at the time of injury.178,235 Thus, time to obtain all preoperative studies is available, allowing for the most controlled circumstance for the surgery. Incongruent reductions occur if there are bony fragments or soft tissue interposed in the acetabulum, preventing a congruous reduction. Free fragments located between the femoral head and acetabular articular cartilage must be removed (Fig. 48-27). These patients may benefit from skeletal traction to relieve the pressure on incarcerated fragments temporarily. This may be an indication for arthroscopic debridement and evaluation of the hip joint depending on the size of the fragment(s). The postreduction CT will demonstrate the location, size, and number of offending bony fragments allowing better planning of the procedure. Fragments treated by debridement include avulsions from the femoral head, inferior femoral head fractures (Pipkin type I), loose fragments from the posterior wall, and cartilage fragments sheared from the femoral head.30,34,37,55,150,184,189,206 Pure hip dislocations, because there are no free bony fragments, have a lower rate of nonconcentric reduction than fracture dislocations of the hip, which generate more bony debris.17,61,85,142,158 
Figure 48-27
CT scan demonstrating a fragment of bone interposed between the femoral head and posterior articular surface that requires removal.
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Open Reduction and Internal Fixation

ORIF is reserved for fracture dislocations. Posterior wall fractures requiring fixation are addressed in Chapter 47, leaving femoral head and neck fractures to be discussed here. In the rare case of a young patient with an associated femoral neck fracture and hip dislocation, the dislocation requires open reduction and the hip fracture should be fixed acutely. If the fracture is not displaced, then fixation of the neck may precede reduction of the hip if it can be accomplished expeditiously. If the neck fracture is displaced, then the femoral head reduction will enable reduction of the neck and should be performed emergently. The treatment of this combination injury becomes different in the older population. For elderly patients, a hemiarthroplasty or total hip replacement may be favorable to ORIF as the hip dislocation adds to the likelihood of AVN. 
Hip dislocations associated with femoral head fractures may also be candidates for ORIF. If the head fragment is small, as in a Pipkin I, the fragment may be excised or debrided. As opposed to Pipkin type II fractures when the fracture line extends cephalad to the fovea and involves the weight-bearing surface of the femoral head accurate alignment is required. In many cases, these fractures align well with reduction of the hip as they are held in their normal position by the ligamentum teres.82 The postreduction CT of the joint in conjunction with the AP and Judet views will demonstrate any displacement. If the reduction is near perfect, then nonoperative management has been recommended.21,96,153,203 If the fragment is not anatomically reduced, then ORIF is performed (Fig. 48-28). Fixation of these fractures can be challenging, as the fragment is frequently shallow, having been caused by a shearing mechanism. 
Figure 48-28
AP radiograph of a patient with a Pipkin type II posterior fracture dislocation of the hip (A).
 
After reduction of the hip, the femoral head fragment was not reduced and the hip was not reduced concentrically (B). CT scan demonstrates the femoral head fragment to be rotated 180 degrees (C). The fracture was reduced and fixed with large Herbert screws via an anterior approach (D, E).
After reduction of the hip, the femoral head fragment was not reduced and the hip was not reduced concentrically (B). CT scan demonstrates the femoral head fragment to be rotated 180 degrees (C). The fracture was reduced and fixed with large Herbert screws via an anterior approach (D, E).
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Figure 48-28
AP radiograph of a patient with a Pipkin type II posterior fracture dislocation of the hip (A).
After reduction of the hip, the femoral head fragment was not reduced and the hip was not reduced concentrically (B). CT scan demonstrates the femoral head fragment to be rotated 180 degrees (C). The fracture was reduced and fixed with large Herbert screws via an anterior approach (D, E).
After reduction of the hip, the femoral head fragment was not reduced and the hip was not reduced concentrically (B). CT scan demonstrates the femoral head fragment to be rotated 180 degrees (C). The fracture was reduced and fixed with large Herbert screws via an anterior approach (D, E).
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The approach used to reduce and fix the fracture is also debated. Because the fracture is caused by the femoral head impinging on the posterior wall of the acetabulum in an internally rotated position, the fracture fragment of the head is located anteromedially. Moed and Maxey139 demonstrated that the fracture angle in these cases is usually between 25 and 45 degrees off the sagittal plane, creating an anteromedial fragment. Although Epstein had recommended debridement of the joint via a posterior approach to utilize the already damaged capsule, this may not apply to femoral head fractures.196,203,206 To reduce and fix an anteromedial fracture of the femoral head from a posterior approach, the hip may require redislocation. Even with the femoral head out of the acetabulum, anatomic reduction may be difficult without disrupting the ligamentum from the femoral head fragment, potentially devascularizing it. Positioning the intact posterolateral head against the anteromedial fragment without disrupting its soft tissue is extremely difficult, and at best visualization of only a portion of the fracture is possible. In addition, the posterior approach may further compromise the MFCA, the blood supply to the femoral head, making other surgical approaches more appealing. 
In contradistinction to the posterior approach, an anterior approach allows for direct visualization of the femoral head fragment without redislocating the hip. External rotation of the hip allows for cleaning of the fracture bed and accurate reduction of the fragment. Since the major blood supply to the femoral head arises from the posterior cervical branches (MFCA), which may be damaged, there is a consideration for an anterior surgical dissection. Swiontkowski et al.203 compared the anterior and posterior approaches in the management of femoral head fractures meeting operative criteria. The incidence of AVN was not increased in hips treated via the anterior approach versus the posterior approach. The anterior approach allowed for an easier reduction and better visualization. Of note, however, there was a slightly higher rate of heterotopic ossification after anterior approaches that did not affect outcome. Stannard et al.191 also found a higher rate of AVN after posterior than anterior approach for treatment of femoral head fractures. Four of five patients treated via a posterior approach developed AVN to some degree. 
A trochanteric osteotomy with a surgical dislocation of the hip, described by Ganz et al.64 has also been described to treat these fractures.46 More commonly used to treat the prearthritic condition of femoroacetabular impingement the approach is ideal for treating femoral head fractures. Siebenrock180,181 has also reported using this approach to treat acetabular fractures. More recently, his colleagues reported on a series of 12 patients with femoral head fractures treated with surgical dislocation.76 In this group, 83% had good-to-excellent outcomes as compared with 21 patients treated through other approaches (Watson-Jones, Smith-Petersen, and Kocher-Langenbeck) at their institution in whom only 56% of patients had good to excellent outcomes.101 Other authors have also described this technique for femoral head fractures, in particular those with combined posterior wall lesions.66,104,187 While this is a logical approach for the treatment of femoral head fractures, thus far only small numbers of patients have been reported on. As more patients are treated with this approach, better comparisons with other approaches will be possible in terms of the complication rates and medium to long-term outcomes. 
Fixation of the fragments is often difficult due to the shallow nature of the fragment. Techniques that allow for subarticular fixation are necessary. These include the use of screws with no heads, such as Herbert screws or Acutrax screws, countersinking screws with heads, resorbable pin fixation, and suture repair. Regardless of the chosen technique, it is imperative that the fixation is in subchondral bone and does not protrude (Fig. 48-29). Stannard et al.191 recently reported a high failure rate of cannulated 3.0-mm screws made to screw into special washers (Synthes, Paoli, PA) and recommended against their use. 
Figure 48-29
Example of screws used to fix an anatomically reduced femoral head fragment that may not be seated below the articular surface of the head and can cause wear of the acetabulum.
(Courtesy of J. Sledge.)
(Courtesy of J. Sledge.)
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The final indication for ORIF is in the case of a large femoral head impaction injury. Recent biomechanical studies have shown that a 2 cm2 area must be present to significantly affect the contact force distribution in the hip.102 If such an injury exists, the impacted area can be elevated and grafted as described by Mast.127 This should be considered if an impacted area of 2 cm2 exists in the weight-bearing portion of the head. 

Surgical Procedure/Approaches

The direction of the dislocation will dictate the surgical approach necessary to obtain a reduction. In general posterior dislocations will be reduced with the use of a posterior approach. Anterior dislocations can be reduced by an anterior approach. Anterior approaches used to reduce anterior dislocations include the direct anterior approach Smith-Petersen or Heuter interval, Watson-Jones, or a direct lateral approach such as a modified Hardinge. If there is an incongruent reduction secondary to joint debride or loose bodies arthroscopic debridement has become an accepted surgical approach used by those with experience with hip arthroscopy. This allows for minimal muscle damage, intra-articular evaluation and debridement, and allows for repair of soft tissue injuries such as labral tears and large capsular defects. If the fragments are too large or become trapped inferiorly they may not be accessible to the arthroscopic instrumentation and the surgeon should be prepared to perform open debridement. For instance, Pipkin type I fractures usually can easily be debrided through a direct anterior approach using the Heuter interval. 
In fracture–dislocations, when the surgeon intends to perform an anatomic reduction there is much debate as to the preferred approach. The hip can be approached anteriorly, laterally, or posteriorly. In cases of Pipkin I and IIa direct anterior approach, Watson-Jones, or direct lateral approach may be sufficient (Fig. 48-30). Using a surgical dislocation approach has also been described for these fractures, but is more optimal for Pipkin III and IV injuries, and debridement of large intra-articular fragments. Although a Kocher-Langenbeck can be used for Pipkin IV fractures involving the posterior wall, the surgical dislocation approach as described by Ganz et al., has demonstrated improved outcomes in these divesting injuries.64,66,76,187 
Figure 48-30
 
The Smith-Petersen (direct anterior) and the Watson-Jones (anterolateral) approaches to the hip take the same deep interval but pass on different sides of the tensor in their superficial dissections. The anterior approach is well suited for femoral head fractures while the anterolateral approach is best for irreducible anterior dislocations.
The Smith-Petersen (direct anterior) and the Watson-Jones (anterolateral) approaches to the hip take the same deep interval but pass on different sides of the tensor in their superficial dissections. The anterior approach is well suited for femoral head fractures while the anterolateral approach is best for irreducible anterior dislocations.
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Figure 48-30
The Smith-Petersen (direct anterior) and the Watson-Jones (anterolateral) approaches to the hip take the same deep interval but pass on different sides of the tensor in their superficial dissections. The anterior approach is well suited for femoral head fractures while the anterolateral approach is best for irreducible anterior dislocations.
The Smith-Petersen (direct anterior) and the Watson-Jones (anterolateral) approaches to the hip take the same deep interval but pass on different sides of the tensor in their superficial dissections. The anterior approach is well suited for femoral head fractures while the anterolateral approach is best for irreducible anterior dislocations.
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Arthroscopic Technique in the Management of Hip Dislocations

The use of hip arthroscopy has increased substantially in the last decade. Over this period the instrumentation and techniques have improved and use in the traumatized hip is increasing. Several authors have demonstrated that looses bodies, chondral injuries and labral tears occur as a result of simple hip dislocation and are not detected by initial plain radiographs or fine cut CT scans.133,142,152,229 There is a relative indication for hip arthroscopy in the face of a nonconcentric reduction of a simple dislocation without fracture for the removal of small loose bodies.5,32,91,93,202,229 Hip arthroscopy can be used for fracture–dislocations if the hip is stable and the fragment is small and needs to be debrided. There have been some case reports of fixation with arthroscopy, but this is not advocated as standard practice.111,130 There is no current literature to support the use of hip arthroscopy in concentric hip reductions following simple hip dislocations, despite evidence to suggest the presence of nonradiographic detectable loose bodies may be present.142 In these situations, there may be a role for hip arthroscopy if patients have persistent symptomatic pain with activities. Hip arthroscopy is contraindicated if there are fractures of the acetabulum that would allow fluid extravasation into the pelvis.8 In these situations, an open approach is preferred. 
Preoperative Planning.
If the patient has a nonconcentric reduction of the hip joint the patient should be placed on bed rest or placed in skeletal traction to prevent unnecessary wear of the joint. 
A through radiographic assessment of the hip with radiographs and thin cut CT scans as described earlier should be obtained. Hip arthroscopy is performed in the lateral or supine position. The author prefers the supine position with a fracture table or fracture table extension,23 as this can be performed in the presence of associated injuries. A large, offset peroneal post is preferred to help distract the hip. Skeletal traction or well-padded boots can be used to provide traction through the affected limb and the contralateral foot should also be placed in a boot to act as counter traction. Special arthroscopic instrumentation specific for the hip should be used. These instruments are longer than standard arthroscopic instrumentation. A 70- and 30-degree scope should both be available. If available, specialized articulating graspers can be extremely helpful to facilitate access to all aspects of the central compartment. A fluid pump is also preferred to prevent excess fluid extravasation into the soft tissues (Table 48-10). 
 
Table 48-10
Preoperative Planning Checklist for Hip Arthroscopy
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Table 48-10
Preoperative Planning Checklist for Hip Arthroscopy
Preoperative Planning Check List for Arthroscopy of the Hip following Hip Dislocation
  •  
    OR table: Fracture table or hip distractor bed extension
  •  
    Position/positioning aids: Supine with ipsilateral arm across the chest
  •  
    Fluoroscopy location: Opposite the surgeon from the contralateral side
  •  
    Equipment:
    •  
      70 & 30 degree Arthroscopic cameras
    •  
      Long arthroscopic instruments
    •  
      Articulating graspers
X
Positioning.
Patient is placed supine on the fracture table with a large, well-padded peroneal post. The contralateral foot is placed in a padded boot and gentle traction is applied. The operative limb is also placed in a well-padded boot. Alternatively, skeletal traction can be used. The ipsilateral arm is placed across the patients’ chest on a padded arm-rest. A mayo stand is placed on the operative side close to the patient’s head next to the operating surgeon to hold instrumentation. The arthroscopic viewing screen is placed cranially on the contralateral side. The C-arm is used for fluoroscopic imaging and brought in from the contralateral side (Fig. 48-31). 
Figure 48-31
Diagram of the OR set up for Hip arthroscopy with C-arm coming across from opposite the surgeon.
 
The Mayo stand with instruments is cephalad to the surgeon, the assistant stands below the surgeon.
 
(Adapted from: Safran, MR. Hip arthroscopy—The basics. In: Weisel S, ed. Operative Techniques in Orthopaedic Surgery. Philadelphia, PA: Lippincott Williams and Wilkins, 2010.)
The Mayo stand with instruments is cephalad to the surgeon, the assistant stands below the surgeon.
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Figure 48-31
Diagram of the OR set up for Hip arthroscopy with C-arm coming across from opposite the surgeon.
The Mayo stand with instruments is cephalad to the surgeon, the assistant stands below the surgeon.
(Adapted from: Safran, MR. Hip arthroscopy—The basics. In: Weisel S, ed. Operative Techniques in Orthopaedic Surgery. Philadelphia, PA: Lippincott Williams and Wilkins, 2010.)
The Mayo stand with instruments is cephalad to the surgeon, the assistant stands below the surgeon.
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Surgical Approach.
Once the patient is in position, before prepping and draping the hip, the leg is distracted in abduction to help decompress the hip and then adducted while under traction to create a lateral force on the proximal thigh. Fluoroscopy is used to confirm the hip is able to be distracted 6 to 10 mm to allow access to the central compartment with instrumentation. Once this is performed, the distraction is taken off and the hip sterilely prepped and draped. Draping is the same as for a supine direct anterior approach in case a formal arthrotomy needs to be performed. The hip is then distracted again, with help of the circulating nurse. 
Two main portals are used, an anterolateral portal and an anterior or mid-anterior portal. If necessary a distal accessory anterior lateral portal as described by Kelly et al. can be used for labral repairs if necessary.9 In addition, a posterior portal can be made to assist with more posterior pathology. Prior to portal placement, the ASIS, iliac crest, greater trochanter, lateral femur and patella are palpated and marked to assist with portal placement. The anterolateral portal is the first portal created and is located 1 to 2 cm proximal and 1 to 2 cm anterior to the tip of the trochanter. The skin is incised and with fluoroscopic assistance a spinal needle is placed in the joint followed by a nitinol wire. Fluoroscopy is used to confirm the placement of the nitinol wire into joint and into the cotyloid fossa (Fig. 48-32). 
Figure 48-32
Fluoroscopic image of hip arthroscopy demonstrating nitinol wire in the cotyloid fossa to confirm intra articular placement of an anterolateral portal.
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Once in the joint the anterior portal is created under direct visualization from the anterolateral portal. The anterior portal is placed at the intersection of a transverse line from the tip of trochanter and a longitudinal line from the ASIS. The spinal needle is directed 45 degrees cephalad and 30 degrees medially. Alternatively, a mid-anterior portal can be used, where the anterior portal is placed slightly distal and laterally to the classic anterior portal. 
Additional portals can be used depending on the pathology and are established using direct visualization. A distal accessory lateral portal can be placed approximately 4 cm distal from the midpoint between the anterolateral and anterior portal. Posterolateral portal can be placed at the posterior superior aspect of the trochanter and a proximal accessory portal can also be made, which is in line with the anterolateral portal but a 2 to 3 cm proximal for more lateral based lesions.23,24,26,132 

Technique

As described, the anterolateral portal is established first, followed by the anterior or mid-anterior portal, which is establish using direct visualization with a dry arthroscopic view. Once the anterior portal is created, the joint is insufflated with saline; the portals are then connected with an arthroscopic knife to allow for more maneuverability of the instruments and the camera. With the camera in the anterolateral portal, examination of the central compartment is performed with a 70-degree scope. A systematic approach is taken beginning at the periphery to assess the labrum and the labral chondral junction anteriorly and posteriorly. Once this is performed the camera is placed into the anterior portal in order to inspect the superolateral labrum at the level of the anterolateral portal. The camera can be returned to the anterolateral portal to assess the cotyloid fossa and the ligamentum teres (Table 48-11). 
Table 48-11
Surgical Steps for Arthroscopic Debridement of the Hip after Dislocation
Surgical Steps: Arthroscopic Debridement of the Hip after Dislocation
  •  
    Distract the hip approximately 10 mm to allow access to the hip
  •  
    Establish an anterolateral and anterior portal
  •  
    Assess the central and peripheral compartments of the hip
  •  
    Identify loose fragments
  •  
    Evacuate and loose fragments through the anterolateral portal
  •  
    Debride and/or repair labral injuries
  •  
    Debride and/or repair chondral injuries
X
Once a full inspection of the joint has been performed evacuation of any loose bodies can be performed. Large anterior or superior fragments that prevent a congruent reduction may be embedded into cartilage and will not be free floating (Fig. 48-33). Any fragments that are smaller loose bodies tend to be free floating in the joint and with the patient supine, they tend to settle in posterior aspect of the joint. These free floating fragments of cartilage or bone may be evacuated simply by placing the camera in the anterior portal, and allow the joint to drain out the anterolateral cannula. Obstructing the cannula with an obturator or finger until the joint is filled to capacity can create increased negative pressure to help flush the joint. If flushing the joint is not sufficient, then using arthroscopic instruments such as shavers, biters, or graspers that are angled or straight. Articulating graspers and biters can help remove fragments (Fig. 48-34). 
Figure 48-33
Arthroscopic image demonstrating a piece of cartilage embedded into the acetabular cartilage.
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Figure 48-34
Arthroscopic grasper placed through the anterolateral portal with the camera placed in the anterior portal used to remove loose body.
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X
Once the joint is free of loose bodies, the surgeon can address any labral or chondral injuries. Techniques that may be necessary include labral debridement, labral repair, and microfracture of the subchondral bone for large cartilage lesions. Labral debridement is performed with shavers and radioablation and is limited such that only damaged tissue is removed. If the labral–chondral junction is intact and the labrum is stable then only debridement is performed. If the labrum is avulsed off from its boney acetabular attachment, then debridement and repair of the remaining labral tissue is performed. Placing suture anchors through a distal accessory lateral portal allows for the proper angle for anchor placement to avoid intra-articular placement. Suture anchors are placed, as needed, along the acetabular rim so the labral tissue will be repaired such that the suction seal is recreated. The suture can be placed completely around the labrum in a looped technique or through the labral tissue. Either technique is considered expectable as long as the seal affect is achieved.49,95 
If large unstable chondral flaps are debrided or large areas of delaminated areas are seen then microfracture can be performed in attempt to get bleeding subchondral bone to fill in with fibrocartilage. This is considered a salvage technique as there is little data reporting the clinical outcomes of microfracture in the hip. Some authors have reported noticing an increase in inflammation or even a ruptured ligamentum teres. Debridement of excess surrounding tissue around the ligament can also be debrided. The amount of tissue seen is relative to the timing of the arthroscopy. The more acutely the arthroscopy occurs the less scar tissue is seen, but more inflamed tissue will be seen. The exact clinical sequela of an injured ligamentum teres is still unknown and although there are case reports of ligmentum repairs performed it is unclear if repair is necessary.7,25,152,172,183,225 One author reported that on a second look arthroscopy following a hip dislocation the ligamentum had healed and was fully intact.172 
Once the central compartment is debrided and any labral or chondral pathology is addressed the hip is taken off of traction and the peripheral compartment is inspected for any loose bodies. It has been suggested that hips with different forms of femoroacetabular impingement are more prone to dislocations.13,106,115,152 Two common morphologies implicated are acetabular retroversion and CAM type femurs with an increased alpha angle. If necessary, a femoroplasty can be performed with the traction off and the leg flexed up approximately 30 degrees. There is little evidence to suggest this should be done prophylactically and is a case-by-case decision that is dependent on the patients’ preoperative symptoms, radiographic findings, and surgeon experience. 
Postoperative Care.
Postoperative management following hip arthroscopy is dependent on intra-operative findings. If debridement only is performed a minimum of 2 weeks of foot flat partial weight bearing is recommended but if a labral repair is performed this is extended to 6 weeks. Physiotherapy and the use of cpm can be started early, as range of motion is felt to decrease the incidence of adhesion formation.152 
Prophylaxis for thromboembolic events is recommended with some form of chemical prophylaxis. The rate of dvt/pe following hip arthroscopy appears to be low less than 5% but chemical prophylaxis with aspirin or LWMH is recommended.86,103,121,134,144,182,190 The heterotopic bone formation can occur with elective hip arthroscopy and is prevented with NSAID treatment.12 Radiation therapy is also a possibility, but is not routinely used following hip arthroscopy. 
Potential Pitfalls and Preventative Measures for Hip Arthroscopy.
Arthroscopic management is performed in the acute setting of a dislocated hip that is eccentrically reduced due to loose bodies or concentrically reduced but requires the debridement of loose bodies. In the subacute period, arthroscopy is also helpful, as a persistently painful hip despite a concentric reduction on plain films may benefit from and arthroscopic debridement. Major pitfalls with arthroscopy of the hip are to make sure adequate traction is obtained before establishing portal. The use of a lateralized 25-cm padded post and placing the leg under traction in an abducted position will help distract the hip by lateralizing the femur. This also helps to protect the pudenal nerve from excess pressure preventing a pudenal nerve palsy (Table 48-12). 
Table 48-12
Potential Pitfalls and Preventions: Hip Arthroscopy of Hip Dislocations
Hip Arthroscopy for Hip Dislocations
Potential Pitfalls and Preventions
Pitfall Preventions
Obtain adequate distraction Lateralized well-padded post
Begin traction with leg in abducted position
Proper Equipment Long hip instruments, graspers
Articulating instruments
Be prepared to open Drape out enough to allow for anterior approach
Be prepared to reprep and drape on new table for surgical dislocation or open approach
X

Outcomes following Hip Arthroscopy for Hip Dislocation

Hip arthroscopy following hip dislocation has been demonstrated to be a safe and useful tool in the traumatically dislocated hip.87,142,152,229 Mullis reported the successful debridement in hips following dislocation, and found that 78% of patients without radiographic evidence of loose bodies were found to have loose bodies at the time of surgery.142 No long-term outcomes scores were reported, so it is unclear how removal in these cases affects the outcome of these injuries. Yamamoto229 also, demonstrated the safety of hip arthroscopy in the treatment of these injuries, but noted that 4 of the 11 required conversion to an open procedure due severely displaced fragments and inadequate fixation of fragments. Of their 11 patients, 9 were reported to have excellent outcomes following arthroscopy. Philippon and Ilizaliturri87,152 also showed the efficacy of arthroscopy for traumatized hips, as well as improved function. Phillippon152 reported on 14 professional athletes that were treated arthroscopy after sustain a hip dislocation and all returned to their respective sport following surgery. Ilizaliturri87 reported an improvement of WOMAC scores, with an average preoperative score of 46 which improved to 87 postoperatively. The average time from dislocation to surgery was 3 months with the earliest being 1 month. The varied range of time to surgery following reduction makes it difficult to assess when the optimal time to intervene is following a hip dislocation. Regardless, close monitoring of patients function and pain following hip dislocation with or without radiographic evidence of loose bodies is important as arthroscopic intervention can be successful at relieving pain in persistently painful hips up to several months after the closed reduction is performed. 

Anterior Approaches in the Supine Position for Reduction, Debridement, or Fixation

Open reduction via an anterior approach is indicated when the hip is dislocated anteriorly or if there is an associated femoral head fracture that needs to be reduced and stabilized. Useful anterior approaches can be the direct anterior approach 108 (Smith-Petersen or Heuter Interval) or an anterolateral approach such a Watson-Jones. If an irreducible dislocation is being addressed, then an anterolateral approach, such as a Watson-Jones is usually undertaken. This will avoid dissection too close to the femoral vessels, which are displaced by the dislocated femoral head. Likewise, this is the approach of choice if a displaced femoral neck fracture is present, as it allows for reduction and implant placement through a single incision. The deep interval is the same as the Smith-Petersen, but the superficial dissection is lateral to, rather than medial to, the tensor muscle (Fig. 48-30). 
Preoperative Planning.
Determining the surgical approach is the most important aspect of the preoperative plan. Both the direct anterior approach and the anterolateral approach can be performed in both the supine and lateral position, but in general this is usually performed in the supine position. The next step in planning is to decide if the involved limb with be place into traction or draped free. The use of traction with fracture table or fracture top table with a post will help to access the joint but will limit the surgeons ability to flex the hip. Several orthopedic fracture tables do have the ability to flex the hip up, such as the OSI-PRO Fx or Hana tables (OSI/Muzuno). In addition, the foot can always be detached from the bed by a circulating nurse or an unsterile assistant if more manipulation of the leg is necessary. If the surgeon chooses to drape the leg free a femoral distractor or an able assistant can be used to provide traction and this allows for the leg to be flexed. Flexion of the hip relaxes the anterior hip structures, such as the psoas tendon and the anterior capsule. The hip may reduce with flexion alone. In addition, if it decided to pursue ORIF of the a femoral head fragment, the leg can be place into a figure-of-four position. This flexes, externally rotates, and abducts the leg allowing exposure of the anterior–inferior portion of the femoral head allowing for fixation of the femoral head fragments. This technique is particularly useful for Pipkin I and II fragments when planning for either a debridement or a fixation (Table 48-13). 
Table 48-13
Preoperative Planning Checklist for Debridement of the Hip through an Anterior Approach to the Hip
Preoperative Planning Checklist for Open Debridement of the Hip through An Anterior Approach to the Hip
  •  
    OR table: Radiolucent flattop table or fracture top table with traction
  •  
    Position: Supine
    •  
      Small bump placed under the operative hip (optional)
    •  
      Ipsilateral arm placed across the chest on an arm holder
  •  
    Fluoroscopy location: Comes in from contralateral side opposite the operating surgeon
  •  
    Equipment:
    •  
      Joker
    •  
      Curved retractors
    •  
      Bone hooks
    •  
      Femoral distractor
    •  
      Shanz pin and T-handle
X
Positioning.
The patient is placed supine on the radiolucent bed with a small soft bump placed under the ipsilateral hip and the ipsilateral arm is placed across an arm rest across the patient’s chest. The hip is prepped out and draping should be done to go up to the first rib proximally and along the midline medially to allow assess to the femoral vessels. This should be done both with and without traction. 
Traction obtained by placing or using an existing distal femoral traction or the ipsilateral foot can be placed in a well-padded boot. Distal femoral traction can generate more traction but it can be more difficult to manipulate the leg. Each surgeon should consider the advantages and disadvantages of each type of traction. 

Direct Anterior Approach to the Hip (Smith-Petersen or Hueter Interval)

The direct anterior approach to the hip was first described by Hueter in 1887 and later popularized by Smith-Petersen in north America in 1920s.160 The interval used to access the hip is between the sartorius and the tensor fascia lata (TFL). The limited approach is to incise the skin about 2 to 3 cm lateral and 2 to 3 cm distal to the anterior superior iliac spine and make a 10 to 15 cm incision that is direct toward the head of the ipsilateral fibular head. Once down to the fascia of the TFL, perforating vessels are noted laterally. These vessels demarcate the junction of the tensor and the gluteus maximus fascia. The fascia of the TFL is incised just anterior to these vessels and the TFL muscle belly is retracted laterally. This keeps the intramuscular septum intact and protects the lateral femoral cutaneous nerve, which is in the intramuscular septum. If the fascia is incised more laterally or posterior to the perforating vessels, the tensor is retracted anteriorly and the Gluteus maximus and medius are retracted laterally. This is the Watson-Jones interval. 
With the TFL retracted laterally and the sartorius retracted medially along with the intermuscular septum to protect the lateral femoral cutaneous nerve (LFCN), the deep fascia of the TFL is divided with care as the lateral femoral circumflex vessels traverse this interval. These vessels should be isolated, ligated, and tied off or coagulated (Fig. 48-35). These vessels can be a source of significant bleeding and care needs be taken. Once through the deep fascia of the TFL, a retractor is placed superficially to the capsule superior laterally and underneath the gluteus minimus and medius. Anteromedially, the rectus femoris direct and reflected heads are identified its origin at the anterior inferior iliac spine. The plane between the rectus and the anterior hip capsule is developed and a cobra retractor can be placed to fully expose the anterior hip capsule (Fig. 48-36). If the femoral head has buttonholed through the anterior capsule and further medial exposure is necessary, the indirect and direct heads of the rectus are tagged with heavy, nonresorbable suture and released off the anterior iliac spine (Fig. 48-37). The approach can also be extended proximally if necessary once the rectus is released to get more medial exposure. The skin incision is extended proximally along the iliac crest exposing the external oblique attachments, which are then sharply elevated off the iliac crest. Usually, there is a layer of fat that can be identified this plane is extended proximally to point of the maximum concavity of the iliac wing. A cobb or elevator is used to being elevating the iliacus muscle off the inner table, by packing a lap down the inner table to the level of the iliopectineal line. Once the proximal exposure is completed, by flexing the leg more the psoas can be retracted medially if necessary to fully expose the anterior wall of the acetabulum. In addition, if more exposure of the anterolateral exposure of the acetabulum is necessary the TFL origin along the iliac crest can be transected back to the gluteal pillar, allowing the TFL muscle to be reflected more laterally. This can become useful if the hip needs be fully dislocated. 
Figure 48-35
The lateral femoral circumflex vessels are in the deep fascia of the tensor fascia lata muscle belly.
 
With the muscle belly retracted laterally these vessels are identified and coagulated. Once these vessels and the deep fascia are divided the hip capsule is the next anatomic structure.
With the muscle belly retracted laterally these vessels are identified and coagulated. Once these vessels and the deep fascia are divided the hip capsule is the next anatomic structure.
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Figure 48-35
The lateral femoral circumflex vessels are in the deep fascia of the tensor fascia lata muscle belly.
With the muscle belly retracted laterally these vessels are identified and coagulated. Once these vessels and the deep fascia are divided the hip capsule is the next anatomic structure.
With the muscle belly retracted laterally these vessels are identified and coagulated. Once these vessels and the deep fascia are divided the hip capsule is the next anatomic structure.
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X
Figure 48-36
Example of view of the femoral head once capsule is divided to expose femoral head for excision of a Pipkin I.
 
Cobra retractors are placed intracapsular around the femoral neck and a sharp, double bent hohman is placed over the pelvic brim onto the iliopectineal eminence and retracts the capsule and the rectus muscle. The direct head of the rectus remains attached to the AIIS.
Cobra retractors are placed intracapsular around the femoral neck and a sharp, double bent hohman is placed over the pelvic brim onto the iliopectineal eminence and retracts the capsule and the rectus muscle. The direct head of the rectus remains attached to the AIIS.
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Figure 48-36
Example of view of the femoral head once capsule is divided to expose femoral head for excision of a Pipkin I.
Cobra retractors are placed intracapsular around the femoral neck and a sharp, double bent hohman is placed over the pelvic brim onto the iliopectineal eminence and retracts the capsule and the rectus muscle. The direct head of the rectus remains attached to the AIIS.
Cobra retractors are placed intracapsular around the femoral neck and a sharp, double bent hohman is placed over the pelvic brim onto the iliopectineal eminence and retracts the capsule and the rectus muscle. The direct head of the rectus remains attached to the AIIS.
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X
Figure 48-37
To improve medial visualization, the direct head of the rectus is released from the AIIS.
 
The Sartorius is either elevated off the ASIS or an osteotomy of the ASIS is performed the inguinal canal and the psoas are all reflected medially. This allow for sufficient exposure to the medial, anterior, and superior portion of the hip joint.
The Sartorius is either elevated off the ASIS or an osteotomy of the ASIS is performed the inguinal canal and the psoas are all reflected medially. This allow for sufficient exposure to the medial, anterior, and superior portion of the hip joint.
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Figure 48-37
To improve medial visualization, the direct head of the rectus is released from the AIIS.
The Sartorius is either elevated off the ASIS or an osteotomy of the ASIS is performed the inguinal canal and the psoas are all reflected medially. This allow for sufficient exposure to the medial, anterior, and superior portion of the hip joint.
The Sartorius is either elevated off the ASIS or an osteotomy of the ASIS is performed the inguinal canal and the psoas are all reflected medially. This allow for sufficient exposure to the medial, anterior, and superior portion of the hip joint.
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X

Anterolateral Approach to the Hip (Watson-Jones)

An anterolateral approach as described by Watson-Jones can also be used to approach the hip when performing an open reduction with or without debridement. A more lateral incision is made compared to the DAA approach and proximally it is curved anteriorly. The fascia of the fascia lata is identified and split midline distally and as one reaches the vastus ridge and trochanter, the fascia is divided posterior to the TFL muscle belly and anterior to the gluteus maximus and thus anterior to the gluteus medius. Once this plane is obtained, cobra retractors are placed as with the DAA, where one goes anteromedially under the rectus and posterolaterally under the gluteus minimus. This will exposed the hip capsule. The hip capsule can be T’d with one limb going longitudinally parallel to the femoral neck and the other limb parallel to the acetabular rim providing access to the femoral neck and femoral head. If further exposure to the neck is needed the T can be converted to an H by releasing the capsule along the intertrochanteric ridge (Fig. 48-38). 
The direct anterior (DAA) and anterolateral approach allows for complete exposure of the anterior aspect of the joint, the neck, and the anterior acetabulum. The vessels may be protected and the hip reduced. The rectus, capsule, labrum, bony fragments, and even the psoas tendon have been implicated in irreducible anterior dislocations. Each of these structures must be evaluated in the case of an irreducible anterior dislocation. Flexion to relax the anterior structures makes the procedure easier. Often a joker or other curved retractor can be used to lever a tight structure over the head and allow for reduction. If there is no tendon blocking the reduction, then distraction of the hip will provide for easier digital inspection of the joint to remove fragments, capsule, labrum, or avulsed muscle. This distraction is performed in flexion and mild rotation using a bone hook on the trochanter to pull laterally. Complete anesthetic paralysis of the patient is required. 
The anterior approach is also useful in some cases of nonconcentric reductions. If careful radiographic and CT evaluation after closed reduction demonstrates that the incongruent reduction is caused by something located anteriorly in the joint, then an anterior approach will allow for removal of the structure without re-dislocating the hip. This is true regardless of the direction of the hip dislocation. An excellent example of this is a type I femoral head fracture in which the fracture fragment is causing an incongruent reduction. A direct approach is used to access the anterior of the joint. Distraction can be provided via the fracture table, manually by an assistant, or by use of a femoral distractor from the anterior inferior iliac spine to the trochanter. The fragment can be removed easily and the capsule repaired. Likewise, soft tissue or bony fragments located in the front of the joint are easily removed via this method. 
If the a direct anterior approach is used and dislocation is required then traction is applied with the assistance of the fracture table, an assistant, or femoral distractor and the leg is maximally externally rotated, extended, adducted. The surgeon places a bone hook around the femoral neck after a full capsulotomy is performed and pulls it anterolateral direction. Once dislocated, keeping the leg externally rotated and adducted, the leg can be flexed up and the femoral head can be placed into a pocket posterior-superior to the acetabulum. A cobra or fang retractor can be placed over the inferior femoral neck and outside the posterior inferior acetabulum to expose the acetabulum to remove any bony debride or offending structure (Table 48-14). 
Table 48-14
Surgical Steps for an Anterior (Smith-Petersen) Approach for Reduction, Debridement, or Fixation of the Hip
Surgical Steps: Anterior (Smith-Petersen) Approach for Reduction, Debridement, or Fixation of the Hip
  •  
    Decide on how important traction and Fracture Table in necessary or a surgical assistant will be able to help and the leg is draped free
  •  
    Incise the skin down to fascia and of TFL and ITB. Identify the perforating vessels and incise fascia laterally on the TFL to avoid getting into intramuscular septum to protect the LFCN
  •  
    Retract TFL laterally and Sartorius with intramuscular septum medially
  •  
    Identify the lateral circumflex vessels then coagulate or ligate them
  •  
    If reduction required tag and release both the reflected head of reactus off the ileum
    •  
      Incise the capsule in a T- or H-shaped manner, and include any capsular disruption into the capsulotomy to free up the femoral head
    •  
      Use of a bone hook around the femoral neck can assist in reduction
    •  
      A T-handle on a Shanz pin placed into the femoral neck from vastus ridge can also be used to control the proximal femur
  •  
    External rotation, flexion and abduction can facilitate access to the inferior medial portion of the femoral head (typical location of pipkin fragment)
  •  
    If associated femoral neck fracture then a separate lateral incision may be required to place implants such as screws or plate
  •  
    Alternatively, use of a Watson-Jones approach will allow for reduction of the neck and placement of fixation through a single incision
  •  
    Reduction of head fragments or femoral neck can be done, digitally, with clamps, K-wires, or the use of pins as joysticks
  •  
    Headless screws are used to secure the pipkin fragment
  •  
    Fluoroscopy is used to check congruency and stability of the joint
  •  
    The capsule is loosely closed, rectus is repaired to AIIS through drill holes or with suture anchors
  •  
    Drains are place lying on top of capsule and exist distally and laterally
X

Posterior or Lateral Approaches in the Lateral Position for Reduction, Debridement, or Fixation

Kocker-Langenbeck Approach.
The indications for the posterior approach are an irreducible posterior dislocation, a nonconcentric reduction with posterior interposition, or dislocation associated with posterior wall fracture requiring fixation. Although reduction and fixation of posterior wall fractures is frequently performed with the patient prone, open reduction of an irreducible dislocation of the hip is easiest with the patient in the lateral position.118,119 
Preoperative Planning.
Patients with irreducible or nonconcentric reduction of posteriorly dislocated hip can be reduced via a posterior approach. Careful radiographic assessment of the femoral neck is paramount prior to going to the operating room to avoid displacement at the time of reduction. In addition, if a nondisplaced fracture is suspected the surgeon should be prepared to place cannulated screws and/or 3.2 K-wires across the fracture to stabilize it prior to reduction. Standard hip retractors need to be available. In addition, a Charnely retractor or Adson-Beckman retractors are useful. To help gently reduce the hip large or small bone hooks around the femoral neck can be used to help control the reduction once the obstructing soft tissue is removed. A Schanz pin placed retrograde up the femoral neck from the vastus ridge and attached to a T-handle can provide excellent leverage and control to the reduction. The use of a femoral distractor can also be used to obtain length if the hip needs to be distracted (Table 48-15). 
Table 48-15
Preoperative Planning Checklist for Open Reduction of Posterior Hip Dislocation
Preoperative Planning Checklist Open Reduction of Posterior Hip Dislocation
  •  
    OR table: Radiolucent table
  •  
    Position/positioning aids: Bean bag or Hip positioner for lateral position, Axillary roll, padded Mayo stand
  •  
    (Protect the down side peroneal nerve with gel padding)
  •  
    Fluoroscopy location:
    •  
      Comes from the patient’s front side
  •  
    Equipment: Large hip retractors, Charnley retractor, large and small bone hooks
  •  
    Shanz pin and T-handle chuck
  •  
    Have a femoral Distractor available
    •  
      In rare cases may need to have a hip skid or femoral head pusher available to help with reduction
X
Positioning.
Patients are placed in the lateral position with an axillary roll. A large beanbag or hip positioner is used to secure the patient firmly in the lateral position. The down peroneal nerve is protected by placing a gel padding down and making sure there is no excessive pressure placed at the level of the fibular head. Anticipating that a full Kocher-Langenbeck incision that extends up to the PSIS may be required, it is imperative to prep a large surgical field that includes the PSIS and the entire iliac wing into the field. A surgical assistant in needed to hold the leg for the prep as the leg will not externally rotate normally and the entire leg must be supported. 
Surgical Approach for Kocher-Langenbeck.
A Kocher-Langenbeck approach exposes the posterior aspect of the hip and allows for direct exposure and protection of the sciatic nerve. Identification of the sciatic nerve is the first step of the procedure, as it may be trapped or injured by the dislocation or the reduction. In the face of an irreducible dislocation, the piriformis tendon, maximus muscle, ligamentum teres, labrum, capsular attachment, or bony fragment may prevent reduction. The sciatic nerve may be tented over the dislocated head, which is apparent immediately upon splitting the gluteus maximus muscle. The nerve must be identified at this point in the procedure. This is best accomplished by finding it distal to the area of the disruption. To achieve this, the gluteus maximus tendon can be released at its distal insertion (Fig. 48-39). This takes pressure off the muscular envelope and makes identification of the sciatic nerve more straightforward. The nerve is located medial to the maximus insertion and dorsal to the quadratus femoris muscle. Gentle extension of the hip will take tension off the nerve and the posterior structures. Likewise, the knee should be kept flexed at 90 degrees at all times to relax the tension on the nerve. Once the nerve is identified distal to the hip joint, it is followed proximally and freed from impingement. The nerve emerges as one branch from under (anterior to) the piriformis tendon and passes behind (dorsal to) the obturator internus tendon in 84% of cases11 (Fig. 48-14). In other cases, it may be two branches and either surround or traverse the piriformis tendon. In either case, the tendon must be followed back to its origin from the greater sciatic notch to ensure its safety. After this, the piriformis tendon may be released from the greater trochanter. This will enable the reduction if the piriformis was wrapped under the head and provide better exposure of the joint if necessary. Offending structures are removed from the hip joint and the hip is reduced. If the superior posterior wall is entrapped, it may be attached to the iliofemoral ligament or labrum.20 Prying the fragment inferiorly and posteriorly is possible with distal and lateral traction on the femoral head via the trochanter. Posterior wall fragments or labrum that is stuck in the joint is difficult to free and, on occasion, must be forced anteriorly on its pedicle to remove it. The intact portion of the labrum is always the anchor of these fragments so identification is imperative in determining the direction of removal. If the labrum is intact superiorly, then the fragment must come out superiorly, and vice versa. 
Figure 48-38
If an anterior approach is used for fixation of a femoral head fracture, the radial portion of the capsulotomy should be performed on the acetabular side and the vertical limb directed parallel with the femoral neck (A).
This allows for the best visualization of the femoral head and spares the cervical vessels (B).
This allows for the best visualization of the femoral head and spares the cervical vessels (B).
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X
Figure 48-39
The sciatic nerve runs medially to the insertion of the gluteus maximus tendon and posteriorly to the quadratus.
 
It is safest to identify the nerve distally in the wound by releasing the maximus tendon when performing an open reduction of the hip.
It is safest to identify the nerve distally in the wound by releasing the maximus tendon when performing an open reduction of the hip.
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Figure 48-39
The sciatic nerve runs medially to the insertion of the gluteus maximus tendon and posteriorly to the quadratus.
It is safest to identify the nerve distally in the wound by releasing the maximus tendon when performing an open reduction of the hip.
It is safest to identify the nerve distally in the wound by releasing the maximus tendon when performing an open reduction of the hip.
View Original | Slide (.ppt)
X
After all of the offending structures and fragments are removed from the joint, and the nerve is safely retracted, the hip may be reduced. Again, high-quality radiographs in the operating room are needed to confirm a congruent reduction as evacuation of the joint is challenging. Care should be taken to avoid damage to the medial femoral circumflex vessel within the quadratus femoris. If dissection of this muscle is necessary, it should always be performed from the acetabular side. Once the hip is reduced, labral detachments can be repaired using suture anchors to a freshened cancellous bed.60,208 Small posterior wall fractures are also fixed since the exposure is already available. Spring plates may be used for fragments too small to accept lag screws. Finally, debridement of any damaged muscle, particularly the gluteus minimus, may help prevent heterotopic ossification.162 Repair of all tendons is followed by a careful closure over drains (Table 48-16). 
Table 48-16
Surgical Steps for Open Reduction of the Hip through a Posterior Approach
Surgical Steps: Open Reduction of the Hip Through Posterior Approach
  •  
    Expose iliotibial band and split distally
  •  
    Split the gluteus maximus proximally (feel for femoral head)
  •  
    Keep knee flexed to relieve pressure on sciatic nerve
  •  
    Identify sciatic nerve distally
    •  
      May need to release the insertion of gluteus maximus
    •  
      Follow pirformis tendon to sciatic notch
  •  
    Identify and remove the obstructing anatomy
    •  
      Pirformis tendon
    •  
      Gluteus maximus muscle
    •  
      Ligamentum teres
    •  
      Labrum
    •  
      Capsular attachments
    •  
      Bony fragments
X

Transtrochanteric Approach: Surgical Hip Dislocation

A transtrochanteric approach used to surgically dislocate the hip can be used to treat all four types of Pipkin fractures. The approach, as described by Ganz,64 respects the blood supply to the femoral head and gives excellent access to the femoral head as well as to the articular side of the acetabulum. This approach is particularly useful for the treatment of combined femoral head and acetabular fractures as it allows for full visualization of the femoral head, the acetabulum. 
Preoperative Planning.
Preparing for a surgical dislocation is similar to a posterior approach in the lateral position as it can be performed after a standard Kocker-Langenbeck approach is done to improve the access to the joint. The trochanteric osteotomy can be straight or done in a step cut fashion. This is usually performed with a small ossicaling saw and completed with flat osteotomes. The dislocation of the hip once the capsule is released is anterior and a special hip drape with a sterile bag anteriorly or a spare C-arm drape in necessary to keep the foot and leg sterile while dislocated. Other helpful aid is a padded and sterile mayo stand placed on the posterior side of the patient to help hold the leg in internal rotation and in extension when performing the osteotomy. A large rectangular or “football”-shaped bump is also helpful to help support the dislocated leg. Fluoroscopy is generally used at the end of the case to confirm implant positioning, reduction of the fragments, and congruency of the joint. It can also be used to help with approximating the trochanteric fragment. The screws used to fix the trochanter can be between 50 and 80 mm depending on the trajectory of the screws, and one should have some longer screws around, as a standard small-fragment kit may not have long enough screws (Table 48-17). 
Table 48-17
Preoperative Planning Checklist for Surgical Dislocation of the Hip
Preoperative Planning Checklist for Surgical Dislocation of the Hip
  •  
    OR table: Radiolucent or standard table to accommodate the lateral position
  •  
    Position: Lateral position as described for Kocker-Langenbeck
  •  
    Additional positioning aids:
    •  
      Bean bag or hip positioner
    •  
      Padded Mayo stand
    •  
      Large rectangular bump
Fluoroscopy location: Same posterior approach
  •  
    Equipment: Small-fragment kit
    •  
      Mini-fragment kit
    •  
      Long 3.5- or 4.5-mm screws for Trochanter
    •  
      Pelvic instrumentation
    •  
      Suture anchors available
X
Positioning.
Patients are positioned in the lateral position as described for the posterior approach using either a beanbag or special hip positioner. An axillary roll is placed and the ipsilateral arm is supported on a padded mayo stand. The down peroneal nerve is protected and either a preformed bump or tunnel can be placed over the down leg to support the operative leg or blankets can be used to bump up the leg to a more neutral or slightly abducted position as opposed to being slightly adducted. A second padded mayo stand is set up and will be used to support the operative foot to help hold the leg in slight internal rotation. The surgeon is best positioned posterior to the patient with and assistant above him and an assistant on the other side of the patient. Surgical dislocation of the hip is best performed with a minimum of two surgical assistants. 
Surgical Approach and Technique.
The interval between the TFL and the gluteus maximus, as described by Gibson,68 is used to prevent iatrogenic damage to the gluteus maximus muscle. For optimal exposure, the interval between the TFL and gluteus maximus is divided as proximally as possible and extended to the insertion of the gluteus maximus tendon on the posterior femur distally. Alternatively, a transgluteal approach similar to a standard Kocher-Langenbeck approach can be used to expose the lateral portion of the femur. The posterior portion of the trochanter is identified and prepared for the digastric osteotomy. The posterior portion of the gluteus medius is palpated and the proximal end of the osteotomy is performed exiting through middle of the tip of the trochanter and the gluteus medius tendon. This prevents the osteotomy from injuring the main branch of the MFCA or the anastomosis of the internal gluteal artery and the MFCA, which lies on the posterior border of the piriformis tendon.67,70 The osteotomy exits distal to the vastus ridge and can be performed as a straight or as a step osteotomy10,174 (Fig. 48-40). Once the osteotomy is made, it is elevated anteriorly, the remnant of the gluteus medius is released from the intact tip of the trochanter, and superior border of the piriformis tendon is identified. The gluteus minimus is then dissected off the capsule posteriorly. Anteriorly, to help elevate the vastus lateralis and intermedius off the anterior capsule and anterior femur the hip is slowly abducted, externally rotated, and flexed. The hallmark of the digastric osteotomy is continuity above and below the shallow bone with an intact soft tissue sleeve. 
Figure 48-40
Diagram of the trochanteric osteotomy.
 
The osteotomy can be made as a straight cut (dashed line) or as a step cut (solid line). In either case, proximally the osteotomy starts within the tendon of the gluteus medius in the middle of the tip of the trochanter and ends just distal to the vastus ridge.
The osteotomy can be made as a straight cut (dashed line) or as a step cut (solid line). In either case, proximally the osteotomy starts within the tendon of the gluteus medius in the middle of the tip of the trochanter and ends just distal to the vastus ridge.
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Figure 48-40
Diagram of the trochanteric osteotomy.
The osteotomy can be made as a straight cut (dashed line) or as a step cut (solid line). In either case, proximally the osteotomy starts within the tendon of the gluteus medius in the middle of the tip of the trochanter and ends just distal to the vastus ridge.
The osteotomy can be made as a straight cut (dashed line) or as a step cut (solid line). In either case, proximally the osteotomy starts within the tendon of the gluteus medius in the middle of the tip of the trochanter and ends just distal to the vastus ridge.
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X
Once the capsule is exposed such that the acetabular rim can be palpated a Z-shaped capsulotomy is performed along the superior anterior portion of the femoral neck. At the anterior rim of the acetabulum, the capsulotomy is curved posteriorly and follows along the acetabular rim. The anterior limb of the capsulotomy goes inferiorly along the intertrochanteric ridge in a manner that leaves a cuff of tissue along the ridge to allow for reattachment at closure (Fig. 48-41). With the capsulotomy performed, a bone hook is placed around the femoral neck and, as an assistant flexes and externally rotates the femur, the bone hook is used to subluxate and then dislocate the hip. If the ligamentum is intact to the femoral head it needs to be transected to allow for full dislocation and visualization of the femoral head. This is a safe procedure with respect to the blood supply of the head. With the hip dislocated, the leg is externally rotated and the foot is placed in a sterile bag anteriorly. External rotation allows for more exposure of the femoral head. Fracture fragments and areas of impaction, which usually occur adjacent to the fracture edges, can be addressed (Table 48-18). 
Figure 48-41
Diagram of capsulotomy for a surgical dislocation.
 
The capsulotomy is Z shaped with the transverse portion in line with the femoral neck in the superior anterior portion of the joint. The distal limb should be on the femoral side and the proximal portion going posteriorly should be along the acetabulum, keeping the capsulotomy away from the MFCA.
 
(Modified from: Gardner MJ, Suk M, Pearle, et al. Surgical dislocation of the hip for fractures of the femoral head. J Orthop Trauma. 2005;19:336.)
The capsulotomy is Z shaped with the transverse portion in line with the femoral neck in the superior anterior portion of the joint. The distal limb should be on the femoral side and the proximal portion going posteriorly should be along the acetabulum, keeping the capsulotomy away from the MFCA.
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Figure 48-41
Diagram of capsulotomy for a surgical dislocation.
The capsulotomy is Z shaped with the transverse portion in line with the femoral neck in the superior anterior portion of the joint. The distal limb should be on the femoral side and the proximal portion going posteriorly should be along the acetabulum, keeping the capsulotomy away from the MFCA.
(Modified from: Gardner MJ, Suk M, Pearle, et al. Surgical dislocation of the hip for fractures of the femoral head. J Orthop Trauma. 2005;19:336.)
The capsulotomy is Z shaped with the transverse portion in line with the femoral neck in the superior anterior portion of the joint. The distal limb should be on the femoral side and the proximal portion going posteriorly should be along the acetabulum, keeping the capsulotomy away from the MFCA.
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Table 48-18
Surgical Steps for Surgical Dislocation of the Hip for Open Reduction, Debridement, or Fixation
Surgical Steps: Surgical Dislocation of the Hip for Open Reduction, Debridement, or Fixation
  •  
    Expose iliotibial band and split proximally between the TFL and G. Max.
    •  
      Use the perforating vessels to identify this plane.
    •  
      Go as Proximally as possible to create a large flap of G. Max.
    •  
      Go Distally past the insertion of the G. Max tendon into the femur.
  •  
    If the hip is still dislocated feel for the femoral head under G. Max superiorly and posteriorly.
  •  
    If the hip is reduced slightly abduct and extend the hip to get adequate exposure of the posterior portion of the trochanter.
  •  
    Keep knee flexed to relieve pressure on sciatic nerve and hip internally rotated.
  •  
    Mark out plan for osteotomy to go through the tip of the trochanter and distally exit below the vastus ridge to create a trigastric osteotomy.
    •  
      The hip should be in extension and internal rotation when performing osteotomy.
    •  
      If straight osteotomy is performed try cracking the anterior portion to leave an anterior ridge of bone for the fragment to interdigitate when repaired.
  •  
    Elevate the Gluteus minimus and medius proximally off the capsule with the leg in abduction, can use large rectangular bump to help support leg.
  •  
    Anteriorly elevate the vastus off the femur and the anterior inferior minimus off the capsule as the abducted hip is flexed and externally rotated.
  •  
    Once the capsule is exposed perform Z-shaped capsulotomy. If hip is dislocated and button hole is present, incorporate the capsular defect into the capsulotomy.
  •  
    Usually the hip cannot be freed up or moved until the capsule is released. In the irreducible hips the capsule entraps the femoral head and neck and care should be taken when releasing the capsule.
  •  
    Once the capsulotomy is performed the hip is dislocated. The leg is flexed and externally rotated. The leg in placed in a sterile bag anteriorly.
  •  
    Femoral Head is exposed and the acetabulum is debrided. If a labral repair is required this can be performed at this time.
  •  
    Femoral head fractures are reduced and K-wires and clamps are used to hold fragments in place.
  •  
    The fovea can be used to place antegrade K-wires or the tine of bone forcep when provisionally fixing fragments.
  •  
    Usually the inferior pipkin fragment has the ligament of Wichbricht still attached and every attempt should be made to keep this intact to maintain a blood supply to this fragment. This comes from a branch of the MFCA.
  •  
    Once femoral head is repaired and/or acetabulum is debrided then hip is reduced. The superior and posterior labrum can be rechecked at this time and repaired along with any posterior wall fragments.
  •  
    Small posterior wall fragments can be fixed with small antiglide plates, or debrided.
  •  
    A loose capsular repair is performed to prevent increased intracapsular pressures from hematoma that could occlude the femoral head blood supply.
  •  
    The trochanteric fragment is placed back into the osteotomy bed and fixed with either 3.5- or 4.5-mm lag screws. These should aim toward the lesser trochanter.
  •  
    Fixation of trochanteric fragment requires a 6-week course of footflat partial weight bearing to protect the repair.
X
The advantages of this approach include the ability to expose the entire hip joint, an increased ability to address areas of impaction (Fig. 48-42), visualize the reduction circumferentially, increased ability to treat concomitant labral detachments, and an improved ability to ensure implant placement is not intra-articular. In addition, the surgical dislocation approach allows for the treatment of femoral head fracture with or without associated fractures of the femoral neck or acetabulum (Fig. 48-43).76,101,187 Complete dislocation of the femoral head allows for a thorough debridement of loose bodies from the hip joint. Avulsions or tears of the acetabular labrum are repaired to the acetabular rim with suture anchors, as described for the treatment of femoroacetabular impingement.58 Surgical dislocation has primarily been described for the treatment of femoroacetabular impingement64,65 and acetabular fractures.180,181 More recently, some author’s have reported using a surgical dislocation approach for all femoral head fracture, in particular when there is an associated acetabular fracture.104,187 
Figure 48-42
 
A. AP radiograph of the right hip in a 36-year-old male with a Pipkin type IV injury B. An intraoperative picture of the femoral head demonstrating areas of impaction and cartilage damage. The picture is looking at the inferior aspect of the femoral neck taken from the front of the patient in the lateral position. C. This shows the femoral head from the opposite side of the table, standing behind the patient and looking in the caudal direction.
 
(Courtesy of Prof. Alessandro Massé, San Lugi Ospedale, Torino, Italy.)
A. AP radiograph of the right hip in a 36-year-old male with a Pipkin type IV injury B. An intraoperative picture of the femoral head demonstrating areas of impaction and cartilage damage. The picture is looking at the inferior aspect of the femoral neck taken from the front of the patient in the lateral position. C. This shows the femoral head from the opposite side of the table, standing behind the patient and looking in the caudal direction.
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Figure 48-42
A. AP radiograph of the right hip in a 36-year-old male with a Pipkin type IV injury B. An intraoperative picture of the femoral head demonstrating areas of impaction and cartilage damage. The picture is looking at the inferior aspect of the femoral neck taken from the front of the patient in the lateral position. C. This shows the femoral head from the opposite side of the table, standing behind the patient and looking in the caudal direction.
(Courtesy of Prof. Alessandro Massé, San Lugi Ospedale, Torino, Italy.)
A. AP radiograph of the right hip in a 36-year-old male with a Pipkin type IV injury B. An intraoperative picture of the femoral head demonstrating areas of impaction and cartilage damage. The picture is looking at the inferior aspect of the femoral neck taken from the front of the patient in the lateral position. C. This shows the femoral head from the opposite side of the table, standing behind the patient and looking in the caudal direction.
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Figure 48-43
Pipkin IV.
 
Pipkin III and IV injuries outcomes have improved with used of a surgical dislocation approach. An AP-pelvis-radiograph of a shows a 29-year-old male who sustained a fracture dislocation of the hip that involved both a femoral neck fracture (Pipkin III) and a small posterior wall fracture (Pipkin IV) (A). A surgical dislocation was performed and intra-operatively the surgeon is able to identify all the fragments (B) and protect the retinacular vessels along the femoral neck that supply the femoral head (C). The use of K-wires and threaded K-wires are used to obtain provisional fixation while protecting the femoral head vessels (D). Once provisional fixation of the femoral head is performed headless screws are used to fix the articular fragments and are buried under the cartilage. Cannulated screws are used to obtain some compression of the femoral neck fragment. Threaded K-wires are used to add stability. The labrum and posterior wall were also fixed with suture anchors and an antiglide plate (E, F, G).
Pipkin III and IV injuries outcomes have improved with used of a surgical dislocation approach. An AP-pelvis-radiograph of a shows a 29-year-old male who sustained a fracture dislocation of the hip that involved both a femoral neck fracture (Pipkin III) and a small posterior wall fracture (Pipkin IV) (A). A surgical dislocation was performed and intra-operatively the surgeon is able to identify all the fragments (B) and protect the retinacular vessels along the femoral neck that supply the femoral head (C). The use of K-wires and threaded K-wires are used to obtain provisional fixation while protecting the femoral head vessels (D). Once provisional fixation of the femoral head is performed headless screws are used to fix the articular fragments and are buried under the cartilage. Cannulated screws are used to obtain some compression of the femoral neck fragment. Threaded K-wires are used to add stability. The labrum and posterior wall were also fixed with suture anchors and an antiglide plate (E, F, G).
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Pipkin III and IV injuries outcomes have improved with used of a surgical dislocation approach. An AP-pelvis-radiograph of a shows a 29-year-old male who sustained a fracture dislocation of the hip that involved both a femoral neck fracture (Pipkin III) and a small posterior wall fracture (Pipkin IV) (A). A surgical dislocation was performed and intra-operatively the surgeon is able to identify all the fragments (B) and protect the retinacular vessels along the femoral neck that supply the femoral head (C). The use of K-wires and threaded K-wires are used to obtain provisional fixation while protecting the femoral head vessels (D). Once provisional fixation of the femoral head is performed headless screws are used to fix the articular fragments and are buried under the cartilage. Cannulated screws are used to obtain some compression of the femoral neck fragment. Threaded K-wires are used to add stability. The labrum and posterior wall were also fixed with suture anchors and an antiglide plate (E, F, G).
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Figure 48-43
Pipkin IV.
Pipkin III and IV injuries outcomes have improved with used of a surgical dislocation approach. An AP-pelvis-radiograph of a shows a 29-year-old male who sustained a fracture dislocation of the hip that involved both a femoral neck fracture (Pipkin III) and a small posterior wall fracture (Pipkin IV) (A). A surgical dislocation was performed and intra-operatively the surgeon is able to identify all the fragments (B) and protect the retinacular vessels along the femoral neck that supply the femoral head (C). The use of K-wires and threaded K-wires are used to obtain provisional fixation while protecting the femoral head vessels (D). Once provisional fixation of the femoral head is performed headless screws are used to fix the articular fragments and are buried under the cartilage. Cannulated screws are used to obtain some compression of the femoral neck fragment. Threaded K-wires are used to add stability. The labrum and posterior wall were also fixed with suture anchors and an antiglide plate (E, F, G).
Pipkin III and IV injuries outcomes have improved with used of a surgical dislocation approach. An AP-pelvis-radiograph of a shows a 29-year-old male who sustained a fracture dislocation of the hip that involved both a femoral neck fracture (Pipkin III) and a small posterior wall fracture (Pipkin IV) (A). A surgical dislocation was performed and intra-operatively the surgeon is able to identify all the fragments (B) and protect the retinacular vessels along the femoral neck that supply the femoral head (C). The use of K-wires and threaded K-wires are used to obtain provisional fixation while protecting the femoral head vessels (D). Once provisional fixation of the femoral head is performed headless screws are used to fix the articular fragments and are buried under the cartilage. Cannulated screws are used to obtain some compression of the femoral neck fragment. Threaded K-wires are used to add stability. The labrum and posterior wall were also fixed with suture anchors and an antiglide plate (E, F, G).
View Original | Slide (.ppt)
Pipkin III and IV injuries outcomes have improved with used of a surgical dislocation approach. An AP-pelvis-radiograph of a shows a 29-year-old male who sustained a fracture dislocation of the hip that involved both a femoral neck fracture (Pipkin III) and a small posterior wall fracture (Pipkin IV) (A). A surgical dislocation was performed and intra-operatively the surgeon is able to identify all the fragments (B) and protect the retinacular vessels along the femoral neck that supply the femoral head (C). The use of K-wires and threaded K-wires are used to obtain provisional fixation while protecting the femoral head vessels (D). Once provisional fixation of the femoral head is performed headless screws are used to fix the articular fragments and are buried under the cartilage. Cannulated screws are used to obtain some compression of the femoral neck fragment. Threaded K-wires are used to add stability. The labrum and posterior wall were also fixed with suture anchors and an antiglide plate (E, F, G).
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X
In the original description of this technique for elective cases, Ganz64 reported three trochanteric fixation failures in 213 cases. In Henle’s76 series of 12 patients and Solberg’s187 series of 12 patients with femoral head fractures treated with surgical dislocation, no patient had a nonunion of the trochanteric osteotomy after the primary surgery for fracture fixation. One patient did have a nonunion after a third hip revision for an arthroplasty 6 years following a Pipkin type IV injury. Ganz64 also reported no cases of AVN in his series, demonstrating that the approach does not cause AVN in the elective setting. Solberg187 reported one case of AVN in a Pipkin IV fracture, and Henle76 had two cases of AVN also in type IV injuries, making it difficult to determine if there was a causal relationship of the approach with this complication (Table 48-19). 
Table 48-19
Surgical Dislocation: Potential Pitfalls and Preventative Measures
Surgical Dislocation Hip
Potential Pitfalls and Preventions
Pitfall Preventions
Trochanteric osteotomy placement Expose tip of trochanter to gluteus maximus tendon insertion
Extend and internally rotate the hip
Make step cut or crack anteriorly
Protect MFCA Osteotomy through tip of trochanter
Z-shaped capsulotomy
Avoid devascularization of pipkin fragment Identify the Lig. Weichbrecht
Keep periosteum intact around femoral head
Protruding hardware Countersink articular screws
X
Postoperative Care.
Dislocation without Associated Fracture
There are many recommendations for the treatment of simple hip dislocations.43,88,116,151,173,177,196,206,217 The primary question is whether weight bearing should be delayed. It has been postulated that early weight bearing may cause greater collapse in cases of hip dislocation complicated by AVN.199 This has not been demonstrated in a prospective fashion, but has some merit on historical grounds.17 Several authors have examined the use of MRI to detect changes within the femoral head after dislocation.43,112 Although changes within the femoral head have been demonstrated, the long-term outcome of patients with these changes has not been determined. These studies indicate that MRI may have future use in predicting which patients may develop AVN and therefore help to determine whether early weight bearing is a risk for degree of collapse. However, at this point, there is no consistent way to predict eventual AVN. Since the rate of AVN is highest in hips reduced after 6 hours, it may be reasonable to delay full weight bearing in these cases for 8 to 12 weeks. In the absence of fracture fixation, patients requiring open reduction may be treated with the same protocol as after successful closed reduction. 
For patients whose hips have been reduced within 6 hours, the standard postreduction regimen includes a brief period of rest for several days to 2 weeks followed by mobilization. Continuous passive motion is desirable to avoid the intra-articular adhesions and arthritis that come from long immobilization.211 Extremes of motion are avoided for 6 to 8 weeks to allow for capsular healing. Likewise, early mobilization of patients is best for their overall condition. Patients should be out of bed to a chair within a few days and up on crutches or a walker within 1 week. Typically, the affected side is allowed toe touch weight bearing to provide the least stress to the hip joint by resting the leg on the ground during ambulation. As patients’ strength returns and they are able to better control the limb, weight bearing is increasingly permitted. Most patients can achieve full weight bearing by 6 weeks. 
Rehabilitation goals include restoration of motion and strengthening the hip musculature. In particular, therapy should concentrate on the abductor muscles to diminish the patient’s need for ambulatory assistive devices. After muscle strength is restored, proprioceptive training and coordination exercises will help the patient regain maximal function. 
Dislocations with Associated Fractures
The rehabilitation for patients who had associated fractures fixed is determined by the associated injury. In the case of posterior wall acetabular fractures or femoral head fractures, active hip motion may be deferred for approximately 6 weeks. Passive motion is encouraged via a continuous passive motion machine. Foot flat weight-bearing ambulation begins immediately and continues for 10 to 12 weeks. Therapy to strengthen the hip musculature is instituted when full weight bearing begins. Hip dislocations with associated femoral neck fractures are treated based on the type of fixation and the type of femoral neck fracture without regard for the dislocation (see Chapter 49). 

Outcome/Results

Patients with femoral head fractures have had similarly disparate to poor results reported compared to simple dislocations. The type of femoral head fracture and their management does correlate with outcome. Matejka et al.129 followed 51 patients with femoral head fractures for a minimum of 24 months. Thirty of the 38 with complete follow-up had been treated with fixation or excision of the fragment. Eleven developed AVN and 16 arthritis, with 11/30 going on to total hip arthoplasty. Yoon et al.233 followed 30 patients for 3 to 10 years after injury. Smaller fragments were excised (n = 14) and larger ones fixed (n = 16). Overall, good or excellent results were found in 21 clinically and radiographically. Marchetti et al.125 reported no excellent, 67% good, 18% fair, and 15% poor results in 33 patients at an average of 49 months. Results for Pipkin type I and II fractures were better than type III and IV fractures (p < 0.02). Finally, Dreinhofer et al.44 reported similar results to those they found in pure hip dislocations. Twenty-six patients followed for an average of 5 years (2 to 11) resulted in 6 with arthritis, 5 with AVN, and 8 with HO. By the Thompson and Epstien206 criteria, 15/26 had fair or poor results. 
Several recent reports included evaluation using standardized outcome scoring. Stannard et al.191 evaluated the clinical and radiographic outcome of 22 patients at an average of 24 months after injury using the SF12 outcome scale. Radiographic findings correlated well with SF12 scores, with poor results having an average physical score of 29 as compared with over 42 for all other groups. Outcome was not different, with only small groups, for patients managed with ORIF of the head (typically larger more proximal fractures) versus excision (smaller inferior fragments), or an anterior versus posterior approach. AVN had a substantial negative effect on outcome with an average physical score of 27 for the 5 patients who developed it as compared with 44 for those that did not. Nork and colleagues161 evaluated 37 patients treated with ORIF (21) or excision (13) via an anterior approach at a minimum of 40 months using the musculoskeletal functional assessment (MFA). Half of the patients had small posterior wall fractures of less than 10%, which did not affect the stability of the joint. Fifty-eight percent developed HO, and 6% developed AVN. Nineteen patients who were evaluated using the MFA had results similar to other isolated lower extremity injuries (average 22.7). Their results were lower than population based norms in 8/10 subcategories. With a small number of patients in each group, no associations could be made related to management or injury type. 
Excellent and good outcomes have been reported for femoral head fractures with combined acetabular fractures. In two separate studies, Solberg187 and Zlowodzki236 both reported excellent and good outcomes in Pipkin IV injuries when using the surgical dislocation approach with a trochanteric osteotomy. Each study only evaluated 12 patients, but 21 of the 24 patients were reported to have an excellent or good outcome after 2 years. These two small reports suggest functional improvements may be seen with this approach but further evaluation of the long-term outcomes is necessary. 

Management of Expected Adverse Outcomes and Unexpected Complications in Hip Dislocations and Fractures of the Femoral Head

Prereduction Considerations in Hip Dislocations and Fractures of the Femoral Head

As previously described, the most important part of the initial assessment is avoiding complications. The most dangerous of these is a missed associated injury. Specifically, nondisplaced hip fractures that may be displaced with attempts at closed reduction must be identified. Likewise, significant knee ligament injuries may occur, necessitating vascular assessment of the leg. Complete neurologic and vascular assessment will provide a necessary baseline for the postreduction examination. Sciatic nerve dysfunction at the time of presentation is reported in up to 19% of patients and is more common in fracture dislocations than pure dislocations.53,78,85,151,195,196,206 The peroneal division is most often affected, so peroneal strength must be tested.195 If the sciatic nerve is injured at the time of the dislocation, then reduction of the head is more imperative, as this may take pressure off the nerve. Functional recovery occurs in approximately 70% of cases and is related to the degree of initial injury, with complete palsies having a worse prognosis than partial palsies.52,55,76,85,154,170,175,186,196,212 If recovery does not occur, patients may be offered tendon transfer at the ankle if they do not wish to use a walking ankle-foot orthosis. Exploration of the nerve is generally not recommended. 

Postreduction Considerations in Hip Dislocations and Fractures of the Femoral Head

As soon as possible after the reduction, the neurologic function of the limb should be reassessed. Specifically, the sciatic nerve function needs to be documented. If nerve function was normal before the reduction and significantly impaired after the reduction, then surgical exploration of the nerve is recommended to ensure it is not trapped within the joint.72 
Regardless of the method, the adequacy of the reduction must be clearly documented with the use of plain films and CT. Likewise, small fragments interposed within the articular surface must not be missed as third-body wear will occur quickly. For this reason, if the head is generally reduced within the acetabulum but is incongruous, a femoral traction pin should be placed and the hip distracted using skeletal traction to avoid articular damage until the offending structures can be removed. 
Recurrent dislocation does not generally occur unless there is an associated fracture. If a large posterior wall fracture exists that may engender instability, then the hip should be placed in skeletal traction with the hip minimally flexed to maintain reduction until stability testing can be performed. 

Late Complications in Hip Dislocations and Fractures of the Femoral Head

Avascular Necrosis

AVN is predominantly present after posterior dislocation and correlates with the time to reduction.3,17,43,54,80,85,141,151,163,173,196,206,216,231 It is reported in 1.7% to 40% of various series. If the hip is reduced to within the confines of the acetabulum within 6 hours of the dislocation, then AVN rates are 0% to 10%. 
The cause of the avascular injury is thought to be multifactorial. In part, the cervical vessels to the head and the contributions from the ligamentum teres are damaged at the time of injury. Secondarily, an ischemic insult to the femoral head while it is dislocated affects outcome. The mechanism of AVN has been studied in rabbits. Shim178 and Duncan and Shim45 have demonstrated femoral head ischemia in adult rabbits caused by dislocation. Contrary to previous beliefs, they found that the cervical vessels to the head are not normally disrupted by the dislocation, but do not provide adequate circulation due to spasm of the larger vessels or of the cervical vessels themselves. Early reduction restored the vascular supply to the head better than late reduction, in some cases almost to the level of the contralateral hip based on angiographic studies. Yue et al.235 found a similar kinking effect in human cadavers. Extrapolated to the clinical situation, this work indicates that the majority of AVN is secondary to the initial ischemia of the femoral head, not to torn vessels, and that emergent reduction may reduce the incidence of AVN. This parallels the clinical findings of many authors who report much lower rates of AVN if the hip is reduced within 6 hours17,163,196 (Table 48-7). 
AVN may take many forms. Radiographic findings are usually present within 2 years, but have been seen to occur as late as 5 years postinjury.209 The diagnosis may be difficult until collapse is present, particularly if the patient develops heterotopic ossification, as this may obscure the radiographic findings. Fortunately, as opposed to AVN secondary to systemic illness or medications or idiopathic AVN, post-traumatic AVN may be highly localized. It is therefore more amenable to treatment by osteotomy than global AVN. The treatment begins with a period of motion and nonweight bearing to diminish the amount of collapse once the diagnosis is made. 

Arthritis

The most common complication after hip dislocation is arthritis206 (Table 48-7). It is more common in posterior dislocations than in anterior dislocations.43 New evidence from the lab suggests that a prolonged dislocation time will increase in chondrocyte apoptosis with increasing time to reduction in a rat model for hip dislocation.50 Fracture dislocations are also more likely to develop arthritis.52,56,141 Dislocations with associated femoral head fractures may develop arthritis in 50% of patients. The higher rates of arthritis in fracture dislocations may be in part from chondrocyte damage, as marginal cartilage injury is common in cases of fracture dislocation.19,119 Repo and Finely164,211 were able to induce chondrocyte death by applying a 20% to 30% strain. Similarly, Borrelli et al.211 demonstrated subchondral fractures and decreased metabolic activity in cartilage exposed to a compression injury. 
The diagnosis of arthritis in some studies is questionable as AVN, and arthritis may be difficult to distinguish.206 In addition, AVN does lead to arthritis. The incidence of primary arthritis is highest in severely injured patients.17,120,141,214 The effect of open reduction on later degeneration is not clear. Stewart and Milford196 reported a 71% incidence of arthritis after open reduction compared with only 48% after closed reduction. Brav,17 Morton,141 and Stewart,197 however, did not find this relationship. 
One of the largest studies to date comes from Dreinhofer et al.,43 who reported on 50 patients after dislocation without associated fracture: 38 were posterior and 12 anterior. Despite all but one of the hips being reduced within 6 hours (mean 70 minutes), they reported a 26% incidence of arthritis at an average of 8 years postdislocation. Six of the seven patients without associated severe injury had a good or excellent result as compared with only three of eight who had a severe associated injury. In contradistinction to other reports, they found no increase in the incidence of arthritis with length of follow-up. They also reported that the majority of patients with radiographic signs of AVN did not manifest radiographic signs of arthritis. 

Heterotopic Ossification

Heterotopic ossification (HO) is very common after posterior fracture dislocation.16,119 It is most common after open reduction of a posterior dislocation.53,55,199,226,227 This complication is also commonly reported after posterior wall fractures. It is likely due to posterior muscle injury from the dislocation in combination with surgical trauma. In cases of femoral head fracture, Swiontkowski et al.203 demonstrated a higher incidence of HO after ORIF via an anterior approach than a posterior approach. In cases of posterior dislocation, the use of indomethacin may diminish the rate of clinically significant HO. The other choice is to use radiation therapy, usually 700 Gy in one dose. This method is very effective in decreasing the rate of HO, but is not favored in young patients.16,138 HO seems to be related to significant trauma in addition to a dislocation with Pape et al.149 reporting a rate of 60% that was not related to a surgical procedure having been performed. Similarly, Rapp et al.161 reported a 58% rate of HO in patients treated for femoral head fractures via an anterior approach. 

Malunion

Yoon et al.232 reported on three patients who required late excision of an inferior femoral head fracture due to pain and limitation of motion. These patients were initially treated with nonweight bearing and then gradual ambulation. In each case, the inferior fragment was excised restoring motion. 

Sciatic Nerve Dysfunction

Late sciatic nerve dysfunction has been reported by several authors.41,74,78,100 It is usually from HO either compressing the nerve or causing it to be stretched. It is important to continue to examine the nerve function at each postinjury visit, as early decompression may favor neurologic return. 

Authors’ Preferred Method of Treatment for Hip Dislocations and Fractures of the Femoral Head

For all cases of hip dislocation, the goal is to obtain a congruent and stable hip. The initial management is directed at reducing the head to within the confines of the acetabulum in order to minimize the ischemia of the femoral head and subsequent AVN. If an associated femoral neck fracture is present, this can be fixed with percutaneous screw fixation or if displaced then immediate open reduction is performed. An irreducible hip requires an immediate open reduction. After the femoral head is within the confines of the acetabulum, the hip will fall into one of three categories: Congruent reduction without associated fracture, congruent reduction with associated fracture, or incongruent reduction. The ultimate management will then be determined by whether the associated fracture requires fixation, and the stability of the hip as shown in the algorithm (Fig. 48-44). 
Figure 48-44
Algorithm for management of hip dislocations and femoral head fractures.
Rockwood-ch048-image044.png
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As in all other dislocations, the congruence of the reduction is assessed. If incongruent, then an open reduction is necessary. The ultimate treatment of the fracture is dependent on its size. If the hip is congruently reduced and a femoral head fracture is present, then the treatment is determined by the size and reduction of the femoral head fracture. If the fracture fragment is small (type I), then it may be treated nonoperatively regardless of its position (Fig. 48-16). If the fragment is large and affects the weight-bearing surface (type II), then it is reduced and fixed with low profile or headless compression screws recessed beneath the articular surface. If the fragment is small and caudal (type I), then excision is preferred (Fig. 48-25). If there is a possibility of excision, such as an isolated Pipkin type I, then the hip is approached anteriorly (Fig. 48-38). Since the femoral head fragment is located anteriorly, it is directly visualized via this method and debridement or fixation can be performed. 
If the fracture affects the weight-bearing region of the head, then an anatomic reduction is desirable. The reduction should be assessed on plain films and on 2-mm CT cuts. If there is a near anatomic reduction and the hip is congruent, then close observation is possible. If the reduction is not anatomic, then ORIF is chosen as above (Fig. 48-28). Because the labrum can be involved after a posterior fracture dislocation and there is usually a small a posterior labral avulsion or a small posterior wall acetabular fracture makes the management more complicated. If the posterior wall needs to be fixed, then the femoral head can be fixed. Surgical dislocation of the hip is the preferred approach to allow for fixation of the posterior wall or labrum and the femoral head (Fig. 48-45). If there is a Pipkin type III or IV fracture then a surgical dislocation is performed (Fig. 48-43). Since this approach allows for complete visualization of the femoral head and acetabulum, has become the more preferred method to approach fracture dislocations of the hip, when the femoral head is involved. 
Figure 48-45
 
The combination of a femoral head fracture and posterior wall fracture can create instability and following the outlined algorithm is helpful in determining treatment. This 24-year-old female was in a motor vehicle accident and sustained a posterior fracture dislocation Pipkin type IV injury (A). Subsequent CT scan demonstrated no femoral neck fracture but impaction of femoral head and the presence of a small posterior wall fracture (B). After a closed reduction in OR (C), a repeat CT scan with 2-mm cuts demonstrate reduction of femoral head fragment and the posterior wall fracture (D, E). Due to the combination of injuries a stress test was performed and demonstrated instability (F, G). With instability noted from the stress test and the presence of a femoral head and posterior wall fracture as surgical dislocation was performed to repair the femoral head fracture. The labrum and posterior wall fragment was repaired with sutures and the posterior wall fracture was reinforced with an antiglide plate (H). The patient continued to have a painless hip at one year (I).
The combination of a femoral head fracture and posterior wall fracture can create instability and following the outlined algorithm is helpful in determining treatment. This 24-year-old female was in a motor vehicle accident and sustained a posterior fracture dislocation Pipkin type IV injury (A). Subsequent CT scan demonstrated no femoral neck fracture but impaction of femoral head and the presence of a small posterior wall fracture (B). After a closed reduction in OR (C), a repeat CT scan with 2-mm cuts demonstrate reduction of femoral head fragment and the posterior wall fracture (D, E). Due to the combination of injuries a stress test was performed and demonstrated instability (F, G). With instability noted from the stress test and the presence of a femoral head and posterior wall fracture as surgical dislocation was performed to repair the femoral head fracture. The labrum and posterior wall fragment was repaired with sutures and the posterior wall fracture was reinforced with an antiglide plate (H). The patient continued to have a painless hip at one year (I).
View Original | Slide (.ppt)
The combination of a femoral head fracture and posterior wall fracture can create instability and following the outlined algorithm is helpful in determining treatment. This 24-year-old female was in a motor vehicle accident and sustained a posterior fracture dislocation Pipkin type IV injury (A). Subsequent CT scan demonstrated no femoral neck fracture but impaction of femoral head and the presence of a small posterior wall fracture (B). After a closed reduction in OR (C), a repeat CT scan with 2-mm cuts demonstrate reduction of femoral head fragment and the posterior wall fracture (D, E). Due to the combination of injuries a stress test was performed and demonstrated instability (F, G). With instability noted from the stress test and the presence of a femoral head and posterior wall fracture as surgical dislocation was performed to repair the femoral head fracture. The labrum and posterior wall fragment was repaired with sutures and the posterior wall fracture was reinforced with an antiglide plate (H). The patient continued to have a painless hip at one year (I).
View Original | Slide (.ppt)
Figure 48-45
The combination of a femoral head fracture and posterior wall fracture can create instability and following the outlined algorithm is helpful in determining treatment. This 24-year-old female was in a motor vehicle accident and sustained a posterior fracture dislocation Pipkin type IV injury (A). Subsequent CT scan demonstrated no femoral neck fracture but impaction of femoral head and the presence of a small posterior wall fracture (B). After a closed reduction in OR (C), a repeat CT scan with 2-mm cuts demonstrate reduction of femoral head fragment and the posterior wall fracture (D, E). Due to the combination of injuries a stress test was performed and demonstrated instability (F, G). With instability noted from the stress test and the presence of a femoral head and posterior wall fracture as surgical dislocation was performed to repair the femoral head fracture. The labrum and posterior wall fragment was repaired with sutures and the posterior wall fracture was reinforced with an antiglide plate (H). The patient continued to have a painless hip at one year (I).
The combination of a femoral head fracture and posterior wall fracture can create instability and following the outlined algorithm is helpful in determining treatment. This 24-year-old female was in a motor vehicle accident and sustained a posterior fracture dislocation Pipkin type IV injury (A). Subsequent CT scan demonstrated no femoral neck fracture but impaction of femoral head and the presence of a small posterior wall fracture (B). After a closed reduction in OR (C), a repeat CT scan with 2-mm cuts demonstrate reduction of femoral head fragment and the posterior wall fracture (D, E). Due to the combination of injuries a stress test was performed and demonstrated instability (F, G). With instability noted from the stress test and the presence of a femoral head and posterior wall fracture as surgical dislocation was performed to repair the femoral head fracture. The labrum and posterior wall fragment was repaired with sutures and the posterior wall fracture was reinforced with an antiglide plate (H). The patient continued to have a painless hip at one year (I).
View Original | Slide (.ppt)
The combination of a femoral head fracture and posterior wall fracture can create instability and following the outlined algorithm is helpful in determining treatment. This 24-year-old female was in a motor vehicle accident and sustained a posterior fracture dislocation Pipkin type IV injury (A). Subsequent CT scan demonstrated no femoral neck fracture but impaction of femoral head and the presence of a small posterior wall fracture (B). After a closed reduction in OR (C), a repeat CT scan with 2-mm cuts demonstrate reduction of femoral head fragment and the posterior wall fracture (D, E). Due to the combination of injuries a stress test was performed and demonstrated instability (F, G). With instability noted from the stress test and the presence of a femoral head and posterior wall fracture as surgical dislocation was performed to repair the femoral head fracture. The labrum and posterior wall fragment was repaired with sutures and the posterior wall fracture was reinforced with an antiglide plate (H). The patient continued to have a painless hip at one year (I).
View Original | Slide (.ppt)
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Controversies and Future Directions Related to Hip Dislocations and Fractures of the Femoral Head

Treatment of hip dislocations requires an immediate reduction of the hip in a paralyzed patient and ideally is performed in the operating room and within 6 hours of injury. Understanding the factors that affect outcomes is still a work in progress. The cartilage damage at the time of injury has been demonstrated to be an important predictor of arthritis and a predictor of total hip replacement.40 The use of MRI has been shown to help recognize soft tissue injuries and insufficiency fractures of the femoral head but its role in the evaluation of acute hip dislocations and recognizing these cartilage lesions remains unclear. In the future, as improvements are made in detecting cartilage damage and early arthritis, MRI may be a useful tool for following these patients after dislocation and recognizing early arthritic changes. 
The use of hip arthroscopy has been suggested in one study to play an important role in the treatment of hip dislocations (114). In this study, 39 hips underwent arthroscopy for the debridement of loose bodies. In 14 hips, there was no radiographic evidence of loose bodies.114 although hip arthroscopy is not indicated for every hip dislocation, it may provide a role in the treatment of these injuries in the future, particularly in the debridement of loose bodies in the face of the stable, concentric hip. 
Hip dislocations associated with a fracture either of the femoral head or the acetabulum significantly change the treatment and outcome of a hip dislocation. The use of the transtrochanteric or surgical dislocation approach has shown some promise in improving the outcome of these injuries. The increased use of the surgical dislocation approach for femoral head fractures with or without an associated acetabular fracture has demonstrated some improved outcomes compared to the more traditional anterior and posterior approaches.66,76,104,187 The improvements in clinical outcomes seen with this approach are encouraging, but more follow-up and comparison studies are needed. In addition, the use of bioresorbable pins has been reported to be useful in the treatment of nine femoral head fractures.159 In this study, they used biodegradable poly-L/DL lactide pins for fixation. The use of biodegradable pins for femoral head fractures has some advantages, particularly allowing for better imaging of the hip, but much more work has to be done to provide enough evidence that these are safe and dependable devices. 

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