Chapter 51: Subtrochanteric Femur Fractures

Adam A. Sassoon, Joshua Langford, George J. Haidukewych

Chapter Outline

Introduction to Subtrochanteric Femur Fractures

Subtrochanteric femur fractures are generally defined as those fractures occurring within 5 cm of the distal extent of the lesser trochanter, and represent an unstable injury. These fractures occur in three specific patient populations: Young patients involved in high-energy trauma, older osteoporotic patients involved in low-energy trauma, and patients exposed to chronic or high-dose bisphosphonate therapy. There is often overlap between the second and third patient population groups, as bisphosphonates are typically used to treat osteoporosis; however, patients with malignancies that are predisposed to bony metastasis occasionally fall into this category as well.22 Bisphosphonate-related subtrochanteric fractures are often the result of low-energy trauma, but have also been reported as spontaneous fractures.28 
Subtrochanteric fractures of the femur present a challenge for the treating surgeon, as the deforming forces on both the proximal and distal segments are difficult to control, especially given the inherently short length of the proximal segment. The characteristic deformity encountered is a flexed, abducted, and externally rotated proximal segment secondary to the pull of the iliopsoas, gluteus medius, and short external rotators, respectively. The distal segment is often shortened and adducted via the unopposed pull of the adductor magnus and longus. 
In addition to the obstacles faced in obtaining an anatomic reduction, the surgeon must ensure that the reduction is maintained throughout the healing process. A substantial demand is placed on the implanted hardware, as the subtrochanteric region of the femur experiences mechanical forces several multiples of the patient’s weight. Various fixation options, including intramedullary (IM) and extramedullary devices, are available to accomplish this goal. 
This chapter will discuss the presentation, investigation, classification, guiding treatment principles, surgical options, expected outcomes, and complications of subtrochanteric femur fractures. 

Assessment of Subtrochanteric Femur Fractures

Mechanisms of Injury for Subtrochanteric Femur Fractures

Subtrochanteric femur fractures generally occur as a result of high-energy trauma in the young patient population. Common mechanisms include motor vehicle collisions, all-terrain vehicle accidents, motocross accidents, falls from height, and industrial mishaps. Significantly less force is required for a subtrochanteric fracture in patients with osteoporotic bone. In this typically older patient population, the most common mechanism of injury is a ground-level fall. Atypical, stress-type fractures occurring in patients exposed to chronic (5 years or greater)18 or high-dose bisphosphonate therapy usually occur from low-energy trauma as well; however, spontaneous fractures in this patient group have also been reported.28 

Associated Injuries with Subtrochanteric Femur Fractures

Patients sustaining a subtrochanteric femur fracture as a result of a high-energy mechanism often have associated life-threatening injuries. Priority to these more significant injuries should be given and advanced trauma life support (ATLS) guidelines should be followed. Head and neck, thoracoabdominal, and pelvic trauma are common and should be ruled out. A thorough secondary survey should be performed to identify any associated fractures. Appropriate resuscitative measures should be performed prior to definitive surgical treatment of subtrochanteric fractures. If prolonged resuscitative efforts are required, damage control orthopedics should be considered and patients should be placed in a temporizing external fixator or skeletal traction to prevent contracture of the surrounding musculature. 
In older patients sustaining ground-level falls, a specific history should be obtained with regard to the mechanism of the fall. Specifically, the occurrence of antecedent syncope, seizures, chest pain, or shortness of breath needs to be assessed so that an adequate medical evaluation can proceed. A history of head and neck trauma should also be obtained. Appropriate imaging, including radiographs and computed tomography (CT) scans, should be ordered when there is clinical concern for a subdural hematoma or cervical spine fracture. A history of previous fragility fractures should also be obtained so that appropriate follow-up with an endocrinologist, or bone health specialist, may ensue following fracture care. 
Specific associated orthopedic injuries, which should be actively sought out in high-energy trauma patients, include femoral neck fractures, pelvic ring injuries, spine fractures, patella fractures (dashboard injury), and calcaneal fractures (jumper’s fractures). Older patients are at risk for ipsilateral upper extremity fractures including, but not limited to, distal radius, proximal humerus, and humeral shaft fractures. In patients with bisphosphonate-related subtrochanteric femur fractures, contralateral subtrochanteric stress reactions should be evaluated with radiographs of the contralateral femur. 

Signs and Symptoms of Subtrochanteric Femur Fractures

Patients sustaining a subtrochanteric femur fracture are unable to bear weight on the affected limb, which often appears shorter than the contralateral extremity. Significant swelling and ecchymosis about the fracture site is common. The skin should be inspected carefully for signs of an open fracture. Furthermore, abrasions and blisters should be documented and considered critically with respect to subsequent incision placement. A thorough neurovascular examination should be performed to rule out injury to these vital structures. If vascular compromise is suspected an ankle-brachial index should be obtained; if abnormalities are detected a subsequent arteriogram should be performed. 

Imaging and Other Diagnostic Studies for Subtrochanteric Femur Fractures

Plain radiographs are diagnostic for subtrochanteric fractures. Anteroposterior (AP) and lateral views of the affected hip and femur should be obtained in addition to an AP pelvic radiograph. Abduction deformity is easily assessed on AP films, while flexion and external rotatory deformities are appreciated on lateral views. The length of the proximal segment and the diameter of the femoral canal should be noted. Fracture extension proximally into the piriformis fossa, greater trochanter, and lesser trochanter is important to recognize, as it may influence fixation. If fracture extent cannot be easily delineated, a dedicated CT scan is warranted. The unaffected hip, as viewed on an AP pelvis, helps to serve as a template for the neck-shaft angle if a cephalomedullary nail is selected for fixation. Radiographs should be carefully inspected for associated fractures, especially one that involves the femoral neck. In high-energy trauma patients, CT scans of the pelvis are often obtained prior to orthopedic consultation and should be closely scrutinized for femoral neck fractures and pelvic ring injuries. Patients presenting with bisphosphonate-related fractures should have imaging of their contralateral femur to assess for cortical thickening in the subtrochanteric region, which may denote an impending fracture (Fig. 51-1A–F). 
Figure 51-1
Preoperative AP (A) and lateral (B) views of a patient who sustained a bisphosphonate-related subtrochanteric femur fracture.
 
Notice the cortical thickening commonly associated with these atypical fractures. Postoperative images (C, D) demonstrating bony union following treatment with a locked trochanteric entry IM nail. Radiographs obtained during follow-up demonstrated a nondisplaced stress fracture of her contralateral femur with notable cortical thickening (E, F). Although this fracture could have been treated with standard proximal locking in the lesser trochanter, fixation that protects the femoral neck and provides better purchase in the femoral head is recommended in this elderly, osteoporotic patient population.
Notice the cortical thickening commonly associated with these atypical fractures. Postoperative images (C, D) demonstrating bony union following treatment with a locked trochanteric entry IM nail. Radiographs obtained during follow-up demonstrated a nondisplaced stress fracture of her contralateral femur with notable cortical thickening (E, F). Although this fracture could have been treated with standard proximal locking in the lesser trochanter, fixation that protects the femoral neck and provides better purchase in the femoral head is recommended in this elderly, osteoporotic patient population.
View Original | Slide (.ppt)
Notice the cortical thickening commonly associated with these atypical fractures. Postoperative images (C, D) demonstrating bony union following treatment with a locked trochanteric entry IM nail. Radiographs obtained during follow-up demonstrated a nondisplaced stress fracture of her contralateral femur with notable cortical thickening (E, F). Although this fracture could have been treated with standard proximal locking in the lesser trochanter, fixation that protects the femoral neck and provides better purchase in the femoral head is recommended in this elderly, osteoporotic patient population.
View Original | Slide (.ppt)
Figure 51-1
Preoperative AP (A) and lateral (B) views of a patient who sustained a bisphosphonate-related subtrochanteric femur fracture.
Notice the cortical thickening commonly associated with these atypical fractures. Postoperative images (C, D) demonstrating bony union following treatment with a locked trochanteric entry IM nail. Radiographs obtained during follow-up demonstrated a nondisplaced stress fracture of her contralateral femur with notable cortical thickening (E, F). Although this fracture could have been treated with standard proximal locking in the lesser trochanter, fixation that protects the femoral neck and provides better purchase in the femoral head is recommended in this elderly, osteoporotic patient population.
Notice the cortical thickening commonly associated with these atypical fractures. Postoperative images (C, D) demonstrating bony union following treatment with a locked trochanteric entry IM nail. Radiographs obtained during follow-up demonstrated a nondisplaced stress fracture of her contralateral femur with notable cortical thickening (E, F). Although this fracture could have been treated with standard proximal locking in the lesser trochanter, fixation that protects the femoral neck and provides better purchase in the femoral head is recommended in this elderly, osteoporotic patient population.
View Original | Slide (.ppt)
Notice the cortical thickening commonly associated with these atypical fractures. Postoperative images (C, D) demonstrating bony union following treatment with a locked trochanteric entry IM nail. Radiographs obtained during follow-up demonstrated a nondisplaced stress fracture of her contralateral femur with notable cortical thickening (E, F). Although this fracture could have been treated with standard proximal locking in the lesser trochanter, fixation that protects the femoral neck and provides better purchase in the femoral head is recommended in this elderly, osteoporotic patient population.
View Original | Slide (.ppt)
X

Classification of Subtrochanteric Femur Fractures

Multiple classification systems have been developed to help understand subtrochanteric femur fracture patterns and guide treatment. The majority of these systems call attention to the integrity of the proximal fragment, fracture geometry, and the presence of comminution. The Russell–Taylor classification (Fig. 51-2) system focuses on two distinctive features of the proximal segment: Fracture extension into the piriformis fossa and involvement of the lesser trochanter. The value of this classification system is primarily historical given the shift in treatment of subtrochanteric fractures toward IM fixation with trochanteric entry nails; however, it may influence the locking configuration of the nail. The Orthopedic Trauma Association (OTA) system broadly classifies subtrochanteric femur fractures based as oblique, transverse, or multifragmentary (Fig. 51-3). 
Figure 51-2
 
The Russell–Taylor classification system, which focuses on two distinctive features of the proximal segment: Fracture extension into the piriformis fossa (I versus II) and involvement of the lesser trochanter (A versus B).
The Russell–Taylor classification system, which focuses on two distinctive features of the proximal segment: Fracture extension into the piriformis fossa (I versus II) and involvement of the lesser trochanter (A versus B).
View Original | Slide (.ppt)
Figure 51-2
The Russell–Taylor classification system, which focuses on two distinctive features of the proximal segment: Fracture extension into the piriformis fossa (I versus II) and involvement of the lesser trochanter (A versus B).
The Russell–Taylor classification system, which focuses on two distinctive features of the proximal segment: Fracture extension into the piriformis fossa (I versus II) and involvement of the lesser trochanter (A versus B).
View Original | Slide (.ppt)
X
Figure 51-3
The OTA fracture classification system, which is based on fracture location, geometry, and the presence of comminution.
Rockwood-ch051-image003.png
View Original | Slide (.ppt)
X

Outcome Measures for Subtrochanteric Femur Fractures

Bony union at the fracture site generally determines success of treatment; however, in order for this union to generate optimal functional results and patient satisfaction, careful attention must be paid to restoring length, alignment, and rotation of the femur. Other results which are important to note are residual hip pain at the site of nail entry or other symptomatic hardware that cause the patient enough discomfort to warrant a secondary procedure. There are no injury specific outcome scores for subtrochanteric femur fractures, but the Short Form Health Survey (SF-36) physical function and mental health outcome scores are applicable. The University of California, Los Angeles (UCLA) and Tegner scores provide validated measures for determining return to preinjury functional status as well, especially in young active patients. 

Pathoanatomy and Applied Anatomy Relating to Subtrochanteric Femur Fractures

The anatomy of the subtrochanteric region of the femur plays an important role with respect to fracture deformity and the mechanical demand of the fixation construct used to treat the fracture. Significant fracture displacement occurs secondary to the pull of the iliopsoas, gluteus medius, and short external rotators on the proximal fracture segment. These muscles pull this segment into a position of flexion, abduction, and external rotation relative to the distal segment (Fig. 51-4). Furthermore, the unopposed pull of the adductors on the distal segment often leads to femoral shortening. These deforming forces need to be overcome in order to achieve an anatomic reduction. The subtrochanteric portion of the femur contends with the highest compressive and tensile forces in the human skeleton (Fig. 51-5). Fixation constructs used to treat subtrochanteric fractures must be able to tolerate these loads cyclically and maintain reduction during fracture healing. Comminution of the medial cortex increases the demand of the fixation construct, surpassing loads of 1,200 lbs per square inch (in a 200-lb person). Varus malreduction also leads to an increased mechanical stress on the fixation construct by altering the weight-bearing force vector through the proximal segment and contributing to higher compressive forces on the medial cortex. The appropriate relationship between the tip of the greater trochanter and femoral head can be appreciated on the unaffected side, as viewed on an AP pelvis radiograph, and should be restored to prevent a varus malreduction (Fig. 51-6). 
Figure 51-4
 
Following a subtrochanteric femur fracture the proximal segment is pulled into a position of flexion, abduction, and external rotation secondary to the pull of the muscles attaching to the greater trochanter. The shaft segment is usually adducted and shortened.
Following a subtrochanteric femur fracture the proximal segment is pulled into a position of flexion, abduction, and external rotation secondary to the pull of the muscles attaching to the greater trochanter. The shaft segment is usually adducted and shortened.
View Original | Slide (.ppt)
Figure 51-4
Following a subtrochanteric femur fracture the proximal segment is pulled into a position of flexion, abduction, and external rotation secondary to the pull of the muscles attaching to the greater trochanter. The shaft segment is usually adducted and shortened.
Following a subtrochanteric femur fracture the proximal segment is pulled into a position of flexion, abduction, and external rotation secondary to the pull of the muscles attaching to the greater trochanter. The shaft segment is usually adducted and shortened.
View Original | Slide (.ppt)
X
Figure 51-5
Note the highest values recorded occur in the subtrochanteric region.
View Original | Slide (.ppt)
Figure 51-5
Diagram of the forces expressed in pounds per square inch experienced by the femur during weight bearing.
Note the highest values recorded occur in the subtrochanteric region.
Note the highest values recorded occur in the subtrochanteric region.
View Original | Slide (.ppt)
X
Figure 51-6
Radiograph demonstrating a malunion following a varus reduction following a subtrochanteric fracture.
 
Failure to accurately reduce the fracture and obtain a lateral starting point contributed to this malreduction. The relationship between the tip of the greater trochanter and the center of the femoral head should be re-established to help prevent this complication.
Failure to accurately reduce the fracture and obtain a lateral starting point contributed to this malreduction. The relationship between the tip of the greater trochanter and the center of the femoral head should be re-established to help prevent this complication.
View Original | Slide (.ppt)
Figure 51-6
Radiograph demonstrating a malunion following a varus reduction following a subtrochanteric fracture.
Failure to accurately reduce the fracture and obtain a lateral starting point contributed to this malreduction. The relationship between the tip of the greater trochanter and the center of the femoral head should be re-established to help prevent this complication.
Failure to accurately reduce the fracture and obtain a lateral starting point contributed to this malreduction. The relationship between the tip of the greater trochanter and the center of the femoral head should be re-established to help prevent this complication.
View Original | Slide (.ppt)
X

Subtrochanteric Femur Fracture Treatment Options

Nonoperative Treatment of Subtrochanteric Femur Fractures

Indications/Contraindications

The indications for nonoperative treatment of subtrochanteric femur fractures are extremely limited secondary to the deformity created, the instability of the fracture pattern, and the poor outcomes associated with this treatment modality.33 Operative treatment is recommended in all instances unless surgical consent is refused or the patient is deemed an unfit surgical candidate secondary to a prohibitive medical comorbidity. In addition, nonambulators or hemi- and quadriplegic patients can also be considered candidates for nonoperative treatment (Table 51-1). 
 
Table 51-1
Subtrochanteric Femur Fractures
View Large
Table 51-1
Subtrochanteric Femur Fractures
Nonoperative Treatment
Indications Relative Contraindications
Refusal of surgical consent All other instances
Medically unacceptable surgical candidate
Nonambulatory patients
X

Techniques

Nonoperative treatment for subtrochanteric femur fractures consists of bed rest. Traction with the limb positioned in 90 degrees of hip flexion and 90 degrees of knee flexion is a historical treatment that is no longer recommended in favor of superior results with operative intervention. 

Outcomes

As nonoperative treatment has become a predominantly historical treatment for subtrochanteric femur fractures, there have been no recent contributions to the literature concerning the results of this method. The most recent results of nonoperative treatment published in previous series are reported as a subsection of a mixed patient cohort. Seinsheimer26 treated 16% of patients in his series with traction and noted a union rate of 100%; however, five patients healed with 15 to 29 degrees of varus angulation. Furthermore, the nonoperative subgroup suffered from selection bias and had an average age of 34 years, as the author cautioned against the disastrous complications of treating the elderly with prolonged bed rest.26 

Operative Treatment of Subtrochanteric Femur Fractures

Indications/Contraindications

All patients with a subtrochanteric femur fracture who do not have a prohibitive medical comorbidity should be considered for operative treatment. Patients who are nonambulatory can be treated nonoperatively as they do not stand to benefit from functional gains in improved alignment; however, a varus malunion may interfere with perineal care, especially in the setting of a previous adduction contracture. In such a case operative intervention may be preferred. 
General operative fixation options include both nailing and plating techniques, which will serve as the focus of the remainder of the chapter. Given the shorter lever arm and load-sharing characteristics of IM nails, they are the preferred implant in the majority of cases. A biomechanical study comparing cephalomedullary nails, proximal femoral locking plates, and 95-degree blade plates in a subtrochanteric fracture model using cadaveric femora demonstrated less varus collapse, a greater load to failure, a greater number of cycles until failure, and a higher force at failure for the nail construct.8 Despite the biomechanical advantages inherent to nailing, plating techniques may continue to have a role in treating simple fracture patterns with very short proximal segments amenable to an anatomic reduction. Plating techniques may also be useful in cases of nonunion around a nail. 
External fixation of subtrochanteric fractures remains very limited in its scope of use, being reserved as a temporizing strategy in the polytraumatized patient and should not be used for definitive treatment. Hip arthroplasty remains a treatment option in neglected trauma, nonunion, or in cases of pathologic fractures with extensive neoplastic involvement of the proximal segment precluding support of implanted hardware. 

Surgical Procedure: Locked Intramedullary (IM) Nailing

Preoperative Planning.
Preoperative planning begins with a thorough review of the available imaging. The fracture geometry should be understood and the integrity of the femoral neck, greater trochanter, lesser trochanter, and calcar should be evaluated. The patient’s bone quality should be grossly assessed. The magnitude of the deformity should be gauged and the appropriate reduction maneuvers anticipated. The contralateral hip should be imaged and the neck shaft angle should be measured. The diameter of the IM canal should also be measured and an IM nail system with appropriate sizing options should be selected. The anterior femoral bow should also be considered. In cases of excessive anterior bowing, the nail may need to be bent, in which case a tabletop bender should be available. Preoperative assessment of the well leg femoral rotation should be performed to help confirm anatomic restoration if comminution or bone loss prevents an adequate read at the fracture site. In addition, a fluoroscopic examination can be performed on the well leg to help determine anatomic rotation. A true lateral view of the knee is obtained and then the fluoroscope is translated to the hip, while maintaining the device’s rotation. A lateral image of the hip is then obtained. The anteversion of the hip is subsequently measured so that it can be imparted to the affected hip before nail locking. 
The questions that remain for the treating surgeon once a nail has been selected as the implant of fixation include the nail entry point and locking screw configuration. Two entry point options exist: Piriformis entry and trochanteric entry. Good results have been reported for both techniques23,27; however, trochanteric starting points are easier to access due to their lateral location. In addition, this location renders comminution involving the piriformis fossa irrelevant. 
Multiple locking options exist for current nail systems and include a single screw into the lesser trochanter, a large cephalomedullary screw, two screws up the femoral neck into the head (recon mode), and a cross-screw configuration with one screw up the femoral neck into the head, and another into the lesser trochanter (Fig. 51-7). In older individuals or people with poor bone stock, a large-diameter cephalomedullary screw is usually selected for enhanced fixation from the larger thread size. In younger patients with good bone stock, locking options that avoid a large screw tract through the femoral neck are preferred. A recent biomechanical study performed in a subtrochanteric fracture, Sawbones™ model, demonstrated that a crossed locking screw configuration had a higher load to failure and a greater overall stiffness when compared to a standard recon configuration in the same trochanteric entry nail.11 However, caution must be used in interpreting this data before recommending a change from the more traditional locking techniques (Table 51-2). 
Figure 51-7
Radiograph demonstrating a crossed locking screw configuration in a trochanteric entry IM nail.
Rockwood-ch051-image007.png
View Original | Slide (.ppt)
X
 
Table 51-2
ORIF of Subtrochanteric Femur Fractures
View Large
Table 51-2
ORIF of Subtrochanteric Femur Fractures
Preoperative Planning Checklist
  •  
    OR Table: Fracture table (supine) or flat Jackson table (lateral)
  •  
    Position/positioning aids: Supine on a fracture table with the contralateral leg in the lithotomy position, or lateral decubitus
  •  
    Flouroscopy location: Enters field between the legs if set up on a fracture table, or approaches from the anterior side of the pelvis if in a lateral position
  •  
    Equipment: Bone reduction clamps (large lobster claws, Lowman clamp, collinear reduction clamp), retractors (Bennett, Homan, and Deaver), cerclage cables, Cobb elevator, bone hook, intramedullary nail system with appropriate size and locking options, tabletop bender.
X
Positioning.
Two primary positioning options exist for IM nailing of subtrochanteric fractures: Supine and lateral decubitus. Supine positioning is performed on a fracture table. The patient is placed on the fracture table and translated distally until there is firm contact between their perineum and the perineal post, which should be generously padded. The patient’s injured foot is padded, wrapped in a self-adherent dressing, and placed in the traction boot. The well leg is placed in the lithotomy position, appropriately padded, and secured to the leg holder. Fluoroscopic views are then obtained to ensure that adequate intraoperative imaging will be achieved. The fluoroscope enters the field between the patient’s legs for an AP view of the hip and femur. The image is then rotated under the affected leg to obtain lateral views. The affected leg is shaved and cleansed with alcohol. A surgical preparation is subsequently performed with either an iodine-based or chlorhexidine solution. A shower curtain-type drape is then applied to the patient and the procedure is initiated following the surgical pause. 
Lateral positioning usually employs a flat Jackson table. The well leg is padded below the lateral malleolus and fibular head and an axillary roll is tucked underneath the patient. The pelvis is stabilized with the use of a beanbag, table attaching hip rests, or a pegboard. The fluoroscope enters the field from the anterior side of the patient. Skin preparation proceeds as indicated above and the affected leg is draped free with two impervious U-drapes and an extremity drape. Impervious stockinet is placed over the foot and covered in a self-adhesive wrap. 
Proponents of the lateral position note that obtaining a reduction in heavier individuals is facilitated by enabling the distal fragment to flex, thereby matching the deformity of the proximal segment. It also allows easier access to the start point, again especially in heavier patients. The authors, however, contend that a supine position on a fracture table requires less assistance for limb management, facilitates fine-tuning of fracture reduction, and allows for easily obtained, clear, lateral, fluroscopic views of the proximal femur. Finally, polytrauma patients on spine precautions or with thorocostomy tubes may not be able to tolerate lateral positioning. The remainder of the discussion regarding IM nail surgical technique will therefore be from the perspective of performing the procedure in a supine position on a fracture table. 
Surgical Technique.
Attempts at closed reduction are performed briefly using the traction, an F-shaped reduction tool, and an anterior-directed leg support for the distal segment. If adequate reduction cannot be achieved readily through closed means, then the decision to perform an open reduction is made. The degree to which the fracture is “opened” depends on the magnitude of deformity. Generally a stepwise approach is used such that small percutaneous stab wounds are used initially to facilitate clamp placement or the introduction of a picador or Cobb elevator to overcome deforming forces and achieve a reduction. If such attempts also fail to produce an anatomic reduction, then a small incision is made directly over the fracture so that a reduction can be achieved. It is better to make a small incision, use an adjunctive reduction maneuver, and nail the fracture in a well-aligned position than to create a percutaneous malunion in a biologically friendly manner. Fluoroscopy is used to localize the fracture and plan the appropriate incision. Ideally, a single incision is utilized for both fracture reduction and the placement of locking screws; however, if this cannot be accomplished, then an adequate skin bridge should be ensured. Sharp dissection is performed through the skin, subcutaneous tissue, and fascia. Blunt finger dissection is then carried down through the vastus lateralis to the proximal fragment. Great care should be taken to avoid excessive stripping of soft tissues at the fracture site. A clamp is used to gain control of the proximal segment and the deforming forces are opposed so that the proximal femur is placed in an anatomic position or a position of exaggerated adduction to facilitate achieving a starting point for the nail (Fig. 51-8). 
Figure 51-8
 
Fluoroscopic image of a clamp being used to gain control of the proximal segment and counteract the deforming forces so that the proximal femur is placed in an anatomic position to facilitate an accurate starting point for the nail.
Fluoroscopic image of a clamp being used to gain control of the proximal segment and counteract the deforming forces so that the proximal femur is placed in an anatomic position to facilitate an accurate starting point for the nail.
View Original | Slide (.ppt)
Figure 51-8
Fluoroscopic image of a clamp being used to gain control of the proximal segment and counteract the deforming forces so that the proximal femur is placed in an anatomic position to facilitate an accurate starting point for the nail.
Fluoroscopic image of a clamp being used to gain control of the proximal segment and counteract the deforming forces so that the proximal femur is placed in an anatomic position to facilitate an accurate starting point for the nail.
View Original | Slide (.ppt)
X
A separate 3- to 5-cm incision for the starting point is made approximately 4 cm proximal and 1 to 2 cm posterior to the tip of the greater trochanter. These measurements are subject to variability depending on the body habitus of the patient. A guide pin from the nail set can be held over the skin under fluoroscopy to determine the anticipated trajectory of nail insertion and confirm the incision site selected. Sharp dissection is performed through the fascia and a heavy curved scissor is introduced to the level of the trochanter and spread open to provide a less impeded path for instrumentation. The guide pin is then perched on the medial aspect of the greater trochanter on the AP view (Fig. 51-9) and centered on the lateral view. It is imperative that the starting point does not drift laterally, as this can contribute to a varus malreduction and comminute the lateral wall of the trochanter (Fig. 51-10). The guidewire is advanced to the level of the lesser trochanter. The entry reamer is then placed over the guide pin and used to gain access to the IM canal. Both the guide pin and reamer are removed and a ball-tipped guidewire is advanced to the level of the fracture. 
Figure 51-9
AP radiograph demonstrating an appropriate starting point for a trochanteric entry IM nail.
Rockwood-ch051-image009.png
View Original | Slide (.ppt)
X
Figure 51-10
 
Radiograph demonstrating a varus malreduction which, in this case, was the consequence of a starting point that was too lateral.
Radiograph demonstrating a varus malreduction which, in this case, was the consequence of a starting point that was too lateral.
View Original | Slide (.ppt)
Figure 51-10
Radiograph demonstrating a varus malreduction which, in this case, was the consequence of a starting point that was too lateral.
Radiograph demonstrating a varus malreduction which, in this case, was the consequence of a starting point that was too lateral.
View Original | Slide (.ppt)
X
Attention is then turned toward achieving an anatomic reduction. A second clamp can be placed around the distal segment and visualization of the fracture can be achieved through the incision with the help of a well-placed Cobb elevator, Hohmann retractor, or Bennett retractor on the medial surface of the femur. Alternatively, fracture reduction can be assessed radiographically; additional tools such as a bone hook can be passed through the incision to assist with the reduction (Fig. 51-11). The fracture can be held in a reduced position using a clamp (Fig. 51-12) or a cerclage wire. Cerclage technique is particularly helpful when a butterfly fragment exists. 
Figure 51-11
 
Percutaneous reduction aids such as this bone hook can help oppose deforming forces and facilitate an anatomic reduction.
Percutaneous reduction aids such as this bone hook can help oppose deforming forces and facilitate an anatomic reduction.
View Original | Slide (.ppt)
Figure 51-11
Percutaneous reduction aids such as this bone hook can help oppose deforming forces and facilitate an anatomic reduction.
Percutaneous reduction aids such as this bone hook can help oppose deforming forces and facilitate an anatomic reduction.
View Original | Slide (.ppt)
X
Figure 51-12
 
Clamps can be placed percutaneously or through a mini-open approach to maintain a reduction during guidewire placement, reaming, and nail insertion.
Clamps can be placed percutaneously or through a mini-open approach to maintain a reduction during guidewire placement, reaming, and nail insertion.
View Original | Slide (.ppt)
Figure 51-12
Clamps can be placed percutaneously or through a mini-open approach to maintain a reduction during guidewire placement, reaming, and nail insertion.
Clamps can be placed percutaneously or through a mini-open approach to maintain a reduction during guidewire placement, reaming, and nail insertion.
View Original | Slide (.ppt)
X
Once the fracture has been reduced, the guidewire is advanced to the level of the patella. A lateral view of the knee is checked to determine the position of the ball tip relative to the anterior cortex of the femur. In older patients with excessive bow, it is important to position the guidewire centrally or even posteriorly on the lateral image. The length of the nail is then measured, and reaming is begun. In younger patients with good cortical bone stock, distal positioning of the guidewire centrally is usually sufficient to prevent a fracture at the tip of the nail from anterior cortical perforation. In older patients, additional measures are sometimes warranted as the poor cortical bone stock may allow instrumentation or hardware to drift, resulting in an intraoperative fracture. In patients with capacious IM canals, the first reamer is passed the length of the guidewire, however, subsequent reamers are passed only through the femoral isthmus thereby decreasing the risk of anterior cortical perforation. Furthermore, if an excessive anterior bow is noted preoperatively, the nail may be bent additionally using a large tabletop press to accommodate this anatomy. A nail diameter 1 to 2 mm less than the diameter of the first reamer to obtain good “chatter” is selected. In patients with poor bone stock, we avoid reaming distal to the isthmus to prevent any risk of an anterior cortical perforation. The nail is introduced into the IM canal and advanced in a controlled manner (Figs. 51-13 and 51-14). An AP view of the hip is obtained to assess appropriate depth of nail insertion to ensure that locking screws are entering the nail at the appropriate position relative to the femoral head and neck (Fig. 51-15). 
Figure 51-13
Clinical photograph of nail insertion with a clamp in place through a mini-open approach to the fracture site.
Rockwood-ch051-image013.png
View Original | Slide (.ppt)
X
Figure 51-14
Radiographic image taken concurrently with the clinical image shown in Figure 51-13.
Rockwood-ch051-image014.png
View Original | Slide (.ppt)
X
Figure 51-15
 
An AP view of the hip obtained to assess appropriate depth of nail insertion, ensuring that locking screws are entering the femoral neck and head at the appropriate position.
An AP view of the hip obtained to assess appropriate depth of nail insertion, ensuring that locking screws are entering the femoral neck and head at the appropriate position.
View Original | Slide (.ppt)
Figure 51-15
An AP view of the hip obtained to assess appropriate depth of nail insertion, ensuring that locking screws are entering the femoral neck and head at the appropriate position.
An AP view of the hip obtained to assess appropriate depth of nail insertion, ensuring that locking screws are entering the femoral neck and head at the appropriate position.
View Original | Slide (.ppt)
X
If comminution or bone loss has precluded an anatomic read of the fracture, rotation and length should be assessed before locking the nail. Length is straightforward to assess intraoperatively in the lateral position, while it is best measured in the well leg preoperatively when the patient is being treated in the supine position on a fracture table. Rotational assessment should also be assessed preoperatively via a fluoroscopic examination as noted above (see “Preoperative Planning”). 
The nail is locked proximally and then distally. In most cases, static locking options are selected distally; however, in cases with simple transverse fracture patterns, a dynamic option may be considered. Care should be taken to not rotate the distal segment on the nail after proximal locking has occurred in transverse fractures, as this will compromise rotational alignment. 
The wounds are copiously irrigated and the fascia closed with an absorbable braided suture when treating closed fractures. Nonbraided absorbable sutures are used for open fractures. Skin is generally closed with staples and sterile dressings are applied. Before waking the patient from anesthesia, it is imperative that a maximal internal rotation view is obtained to verify the absence of a femoral neck fracture. Furthermore, length, rotation, and knee stability should be evaluated. If a malrotation greater than 15 degrees or a leg length discrepancy greater than 2 cm is noted, surgical revision should be performed under the same anesthetic (Table 51-3). 
 
Table 51-3
ORIF of Subtrochanteric Femur Fractures with IM Nail
View Large
Table 51-3
ORIF of Subtrochanteric Femur Fractures with IM Nail
Surgical Steps
  •  
    Attempt closed or percutaneous reduction
  •  
    Open at the fracture site and gain control of proximal segment if necessary for reduction
  •  
    Position proximal segment to facilitate obtaining a starting point for nail
  •  
    Obtain starting point and perform entry reaming
  •  
    Advance ball-tipped guidewire to fracture site
  •  
    Reduce and clamp fracture if required
  •  
    Advance guidewire, measure nail length, ream
  •  
    Insert nail
  •  
    Lock nail proximally
  •  
    Confirm rotational alignment and length, and lock nail distally
X
Postoperative Care.
Following IM nail placement, most patients are allowed to weight bear as tolerated. Exceptions occur in patients with an absence of bony contact at the fracture site or segmental bone loss. These patients are restricted to 30 lbs of partial weight-bearing for 6 to 12 weeks, depending on bone quality and fracture geometry, and then advanced to weight-bearing as tolerated. Deep vein thrombosis (DVT) prophylaxis is initiated on the first postoperative day and routinely continued for 6 weeks. Patients return to the office for a wound check 2 weeks following their surgery and are subsequently seen with radiographs at 6 weeks, 3 months, 6 months, 1 year, and 2 years. 
Potential Pitfalls and Preventative Measures.
The main pitfalls that are under the surgeon’s control and must be avoided in the treatment of subtrochanteric femur fractures include varus malreduction, rotational deformity, limb length discrepancy, missed femoral neck fracture, and missed knee ligamentous injury. Varus malreduction is primarily addressed by achieving an appropriate starting point for nail entry, keeping in mind that a starting point too lateral will accentuate a varus malreduction.20 Eccentric reaming can also contribute to a varus malreduction and should be avoided by obtaining and maintaining a reduction prior to canal preparation. Rotational and length mismatch can be avoided by obtaining an anatomic reduction. In instances where fracture comminution precludes an anatomic reduction, assessment of the well leg prior to surgery can help avoid length or rotational mismatch. Furthermore, clinical evaluation should be performed following the surgical procedure, before exiting the operating room, to ensure length, alignment, and knee stability. Ipsilateral femoral neck fractures should be investigated prior to surgery with available imaging and again at the conclusion of the surgical procedure with an internal rotation view of the hip. A ligamentous examination of the knee should also be performed following fracture fixation so that injuries can be identified and addressed (Table 51-4). 
 
Table 51-4
Subtrochanteric Femur Fractures
View Large
Table 51-4
Subtrochanteric Femur Fractures
Potential Pitfalls and Preventions
Pitfall Preventions
Pitfall #1: Varus malreduction Prevention 1a: Avoid a lateral starting point
Prevention 1b: Obtain and maintain a reduction before and during reaming
Pitfall #2: Rotational malreduction Prevention 2a: Obtain anatomic reduction
Prevention 2b: Assess contralateral hip anteversion relative to a lateral view of the knee preoperatively and recreate with fixation construct
Pitfall #3: Leg length discrepancy Prevention 3a: Obtain anatomic reduction
Prevention 3b: Measure the well leg preoperatively and recreate with fixation construct
Pitfall #4: Missed ipsilateral injury Prevention 4a: Obtain internal rotation view of the hip to rule out femoral neck fracture
Prevention 4b: Perform ligamentous knee examination to rule out instability
X
Treatment-Specific Outcomes.
The results following the surgical treatment of subtrochanteric femur fractures generally demonstrate a high rate of clinical union and a low rate of reoperation. Malalignments are not infrequent, and these surgeries can be difficult with long operative times and significant blood loss. Mini-open clamp-assisted reduction including the use of cerclage wires has not been associated with additional risk of adverse outcomes and can prevent malalignment.1,29 
Results of subtrochanteric femur fracture fixation are most effectively reported when stratified based on energy mechanism, patient type, and method of fixation. High-energy fractures in a young patient population have been shown to have good outcomes with treatment via nailing techniques. An early series of 95 predominantly high-energy fractures treated with piriformis entry nails demonstrated union in 99% of patients occurring at a mean of 25 weeks.32 A more recent series treating high-energy fractures with a cephalomedullary implant also demonstrated good results, with a union rate of 100% in patients not lost to follow-up.27 
Although reported rates of nonunion following IM nail fixation of subtrochanteric femur fractures are low, these complications require advanced reconstruction techniques when they occur. de Vries et al.6 reported the surgical treatment of 33 subtrochanteric nonunions with a blade plate and noted union in 32 instances at an average of 5 months; however, 5 complications requiring reoperation occurred in this series. The majority of patients in this series did demonstrate good to excellent functional hip scores. Another series of 23 subtrochanteric nonunions reported by Haidukewych et al.13 demonstrated a similar rate of union (95%) achieved via revision fixation using a variety of constructs including IM nails in 15 cases, blade plates in 5, a dynamic condylar screw in 1, a sliding hip screw in 1, and dual large-fragment plates in 1. Eighteen patients in this series required bone grafting and no intraoperative complications were reported. 
Older patients with low-energy trauma treated with IM nails have also been shown to have favorable results in the majority of cases; however, a higher complication and reoperation rate have been described in this population. In addition, these patients have a substantial perioperative mortality rate, which should be communicated to the patient and the patient’s family during the course of their treatment. In their series of 302 low-energy subtrochanteric fractures treated with cephalomedullary nails, Robinson et al.24 noted a 25% mortality rate at 1 year. Of the surviving patients, union was achieved in 98%; however, 7% of patients required a nail revision, 5 deep infections occurred, and 5 fractures occurred distal to the original nail inserted.24 Furthermore, 42% of patients reported residual hip pain, although only 2 patients reported this pain as disabling.24 
Bisphosphonate-related subtrochanteric fractures also require special consideration, as results following their surgical fixation have been shown to be associated with a higher complication rate, including intraoperative fracture in 21%.19 In addition, these fractures may result in higher rates of delayed union and nail revision.30 These fractures have been noted to occur bilaterally in up to 44% of patients.14 It is crucial to screen for a contralateral stress reaction as they have been shown to progress to spontaneous fractures especially if associated with thigh pain.2 Furthermore, the hospital stay and cost following urgent treatment of these fractures is longer than that following prophylactic fixation.2 

Surgical Procedure: Plating

Preoperative Planning.
Patient selection is important when selecting plating as the treatment option for subtrochanteric femur fractures. Short proximal fragments with simple fracture patterns amenable to an anatomic reduction are the best candidates for this fixation method, as poor results have been reported in cases with posteromedial comminution.31 Other relative indications include a small IM canal that would not accommodate available nails or significant pulmonary trauma that would be additionally compromised by reaming and IM instrumentation. Relative contraindications include poor skin condition over the fracture site and bisphosphonate-related subtrochanteric femur fractures, as these have demonstrated extremely poor results with locked femoral plating techniques.19 Radiographs should be scrutinized and a preoperative plan should be generated as with plating performed at any anatomic location. Short oblique fractures benefit from a lag screw either through the plate or as an auxiliary screw. 
Positioning.
The patient should be placed supine on a fracture table with the affected leg padded in a traction boot and the well leg padded in a lithotomy position. This position ensures adequate fluoroscopic imaging in the AP and lateral planes. 
Surgical Technique.
A direct lateral approach is made over the flare of the trochanter deepened through the skin, subcutaneous tissue, and fascia lata. The vastus lateralis is elevated in a submuscular fashion from its origin on the vastus ridge and the lateral femur. The surgeon should be careful to avoid any broad-tipped (Bennett type) retractors medially, and if possible, no medial dissection should occur at all. It is important that any plating technique involve as much “indirect” reduction as possible. Typically, manipulation of the proximal fragment can be performed with simple clamps or joysticks, avoiding large broad-based circumferential clamping techniques, which may further strip soft tissues. All modern plating techniques share several common principles. The proximal fixation must be placed accurately into the femoral head, for example, when using a blade plate, a dynamic hip screw, a dynamic condylar screw, or a locking proximal femoral plate. The plate on the proximal fragment is then reduced to the shaft and this should afford an excellent reduction of the proximal fragment. This “self-aligning” indirect reduction technique is predicated on absolutely accurate positioning of the fixation in the proximal fragment (Fig. 51-16). The neck shaft angle will be accurately restored only if the proximal fixation is accurately placed. Preoperative templating can facilitate accurate placement. Compression is then typically achieved with an articulating tension device or other clamp-based techniques to avoid distraction, and side plate screws are placed in the usual fashion in compression mode. Due to the inherently unfavorable biomechanics when using plates in this anatomic region, it is important that compression be obtained so that the bone can bear some load as well. Essentially, acute compression makes the construct more “load sharing.” The specific surgical techniques for implanting any plate such as a sliding hip screw, dynamic condylar screw, blade plate, or locking proximal femoral plate involve accurate biplanar fluoroscopic vigilance. The relationship of the tip of the trochanter and the center of the femoral head should be very carefully scrutinized to avoid any varus (Figs. 51-17 and 51-18). After the plating is completed, the wound is irrigated and closed in layers in the usual fashion over a suction drain. The patient is placed in a lightly compressive dressing. 
Figure 51-16
Accurate implant positioning in the proximal fragment allowing for a “self-aligning” indirect reduction technique.
Rockwood-ch051-image016.png
View Original | Slide (.ppt)
X
Figure 51-17
A varus malreduction that resulted in nonunion.
 
Varus reduction is a significant risk factor for delayed and nonunion of subtrochanteric fractures.
Varus reduction is a significant risk factor for delayed and nonunion of subtrochanteric fractures.
View Original | Slide (.ppt)
Figure 51-17
A varus malreduction that resulted in nonunion.
Varus reduction is a significant risk factor for delayed and nonunion of subtrochanteric fractures.
Varus reduction is a significant risk factor for delayed and nonunion of subtrochanteric fractures.
View Original | Slide (.ppt)
X
Figure 51-18
Radiograph demonstrating a revision of the nonunion shown in Figure 51-17 with blade plate fixation.
 
Note the restoration of the relationship between the femoral head and the tip of the greater trochanter.
Note the restoration of the relationship between the femoral head and the tip of the greater trochanter.
View Original | Slide (.ppt)
Figure 51-18
Radiograph demonstrating a revision of the nonunion shown in Figure 51-17 with blade plate fixation.
Note the restoration of the relationship between the femoral head and the tip of the greater trochanter.
Note the restoration of the relationship between the femoral head and the tip of the greater trochanter.
View Original | Slide (.ppt)
X
Postoperative Care.
When plating techniques are used, the authors typically recommend a limited weight-bearing protocol for 6 to 12 weeks until some radiographic healing is noted. At that point, a gradual progression to weight-bearing is allowed; however, this decision should be made primarily based on bone quality and the fracture pattern, specifically whether any medial comminution exists. 
Potential Pitfalls and Preventative Measures.
When plating techniques are used, it is critical to perform these in a biologically friendly fashion so that only the lateral aspect of the femur is visualized by the surgical dissection. Plating techniques are biomechanically inferior to IM nailing and, although they can be used effectively, they are very dependent on indirect reduction (and bony contact to allow load sharing) to allow rapid healing and avoid hardware failure. 
Treatment-Specific Outcomes.
The biomechanical and clinical outcomes following plating of subtrochanteric fractures have generally been inferior to those demonstrated with nailing techniques.4,8,9,16,21,25 Prior to the recent generation of locked plating techniques, previous plate designs including 95-degree angled blade plate and the dynamic condylar screw were implemented in the treatment of subtrochanteric fractures. A study by Kinast et al.15 demonstrated the results of using a blade plate with either direct or indirect reduction techniques. They noted a delayed or nonunion in 16% of patients undergoing direct reduction, while none of these complications occurred in the indirect reduction group. These excellent results, however, were difficult to reproduce in other series. Brien et al.4 compared the Zickel nail, 95-degree blade plate, and an interlocking nail in another clinical series and noted a mal- and nonunion rate of 32% in the blade plate group. Dynamic condylar screws were also utilized as an alternative to blade plates, postulated to be an easier and more forgiving form of instrumentation. In a series of 16 patients treated with dynamic condylar screws, Pai17 noted a union rate of 94%; however, varus collapse and shortening were noted in cases with medial comminution. 
While locked proximal femoral plates were conceived as a means to address the technical difficulty associated with fixed angle plates and provide a more rigid construct than dynamic condylar screws, the results following their use have been disappointing.5,10 A 26% treatment failure rate has been reported with these implants and poorer results have been associated with increasing age, tobacco use, and varus malalignment.5 As noted above, these implants have also had a poor track record in instances of posteromedial comminution31 and bisphosphonate-related fractures.19 

Management of Expected Adverse Outcomes and Unexpected Complications in Subtrochanteric Femur Fractures

Malunion of Subtrochanteric Femur Fractures

The incidence of malunion is probably higher than reported. Malunion can result in a varus alignment to the proximal femur, which decreases abductor efficiency due to a more proximal position of the greater trochanter (Fig. 51-19). This can also affect limb length and clinical rotation.12 The amount of deformity that is problematic remains undefined, so the surgeon will have to individualize treatment decisions based on patient complaints and physical examination. There are no large published series on the management of proximal subtrochanteric malunion; however, corrective osteotomy may be indicated if the deformity is severe. Implant choice for corrective osteotomy will depend on the previously placed implants, available bone quality, and defects in the femoral head. The authors prefer to use a 95-degree angled blade plate in this situation since the plate can be placed in the proximal fragment, and a corrective osteotomy performed at the apex of the deformity; when the plate is reduced to the femoral shaft, correct alignment is usually obtained, similar to the technique used for indirect reduction of acute fractures. Also, a plate is an effective technique for maintaining corrected length, rotation, and alignment, which can be problematic with an IM nail in metaphyseal bone. The blade can typically be placed in the inferior femoral head, an area unlikely to be violated by previous internal fixation devices. 
This can also affect limb length and clinical rotation.
View Original | Slide (.ppt)
Figure 51-19
Varus malunion of the proximal femur decreases abductor efficiency due to a more proximal position of the greater trochanter.
This can also affect limb length and clinical rotation.
This can also affect limb length and clinical rotation.
View Original | Slide (.ppt)
X

Nonunion of Subtrochanteric Femur Fractures

Nonunion is a rare but problematic complication of subtrochanteric fractures. The treatment of nonunion will vary; however, the surgeon must determine whether the fracture is aligned in a suitable fashion and can be treated with an exchange nailing or whether there is concomitant malalignment that will require debridement, mobilization, correction of deformity, and revision internal fixation of the nonunion (the latter occurring more commonly) (Fig. 51-20). In general, if the nonunion is well aligned and was previously nailed, then the authors prefer to perform an exchange nailing, with a larger diameter nail, in a closed fashion. A nail with a different locking screw configuration into the proximal fragment will provide better fixation if bony defects from prior fixation are present (Fig. 51-21). If there has been hardware failure, the proximal fragment is short or if there is unacceptable malalignment, then the author prefers an open plating technique with a 95-degree blade plate. Usually an extensive open approach, removing all fibrous tissue from the nonunion site, mobilizing the fragments, correcting the deformity, and revising the fixation will be required. Several studies have demonstrated that successful union can be obtained as long as stable proximal fragment fixation can be obtained.3,13 The authors prefer to use bone graft or an osteoinductive bone graft substitute for atrophic nonunions or those with bony deficiency. Arthroplasty may have a role in the multiply operated nonunion in the elderly patient, especially if the proximal fragment has massive bone defects from prior fixation attempts or articular damage from screw cut out (Fig. 51-22A, B). Arthroplasty in this setting has been shown to have a relatively high rate of complications including periprosthetic fractures and infections, the former of which has been shown to decrease with the use of longer femoral component stems.7 
Figure 51-20
 
Radiograph of a nonunion with significant malalignment, requiring removal of implanted hardware, debridement and mobilization of nonunion, correction of the deformity, and revision fixation.
Radiograph of a nonunion with significant malalignment, requiring removal of implanted hardware, debridement and mobilization of nonunion, correction of the deformity, and revision fixation.
View Original | Slide (.ppt)
Figure 51-20
Radiograph of a nonunion with significant malalignment, requiring removal of implanted hardware, debridement and mobilization of nonunion, correction of the deformity, and revision fixation.
Radiograph of a nonunion with significant malalignment, requiring removal of implanted hardware, debridement and mobilization of nonunion, correction of the deformity, and revision fixation.
View Original | Slide (.ppt)
X
Figure 51-21
Radiograph of a revision nail showcasing a different locking screw configuration into the proximal fragment.
 
This provides better fixation in the face of bony defects inherited from prior fixation.
This provides better fixation in the face of bony defects inherited from prior fixation.
View Original | Slide (.ppt)
Figure 51-21
Radiograph of a revision nail showcasing a different locking screw configuration into the proximal fragment.
This provides better fixation in the face of bony defects inherited from prior fixation.
This provides better fixation in the face of bony defects inherited from prior fixation.
View Original | Slide (.ppt)
X
Figure 51-22
 
A failed revision of a subtrochanteric nonunion with articular damage (A) that was addressed with a long cemented proximal femoral replacement (B). Given the abductor deficiency a constrained liner was selected to improve hip stability. The primary indication for revision to an arthroplasty was the articular damage evident.
A failed revision of a subtrochanteric nonunion with articular damage (A) that was addressed with a long cemented proximal femoral replacement (B). Given the abductor deficiency a constrained liner was selected to improve hip stability. The primary indication for revision to an arthroplasty was the articular damage evident.
View Original | Slide (.ppt)
Figure 51-22
A failed revision of a subtrochanteric nonunion with articular damage (A) that was addressed with a long cemented proximal femoral replacement (B). Given the abductor deficiency a constrained liner was selected to improve hip stability. The primary indication for revision to an arthroplasty was the articular damage evident.
A failed revision of a subtrochanteric nonunion with articular damage (A) that was addressed with a long cemented proximal femoral replacement (B). Given the abductor deficiency a constrained liner was selected to improve hip stability. The primary indication for revision to an arthroplasty was the articular damage evident.
View Original | Slide (.ppt)
X

Infection in Subtrochanteric Femur Fractures

Infection remains one of the most difficult complications to manage and is often associated with nonunion. Early postoperative infection is managed with debridement, retention of stable hardware, and a period of intravenous organism- specific antibiotics. For chronic infections or those with loose or broken hardware, the authors prefer to remove all hardware, thoroughly irrigate and debride the area (including reaming the femoral canal for those with prior IM nail fixation), and place the patient on a period of intravenous organism-specific antibiotics. IM antibiotic spacers can be useful as well to provisionally stabilize the subtrochanteric region. The authors use a metal ball-tipped guidewire as an endoskeleton and surround the wire with antibiotic-loaded bone cement. The definitive fixation with or without bone grafting is then performed after eradication of infection. This usually follows an extended course of PICC line and culture-guided antibiotic therapy administered in collaboration with an infectious disease specialist. Laboratory markers for inflammation (ESR and CRP) are checked 2 to 4 weeks following the completion of antibiotic therapy to check for normalization as a surrogate to gauge efficacy of treatment. For extremely unstable fractures, temporary external fixation can be useful until definitive fixation can occur (Table 51-5). 
 
Table 51-5
Subtrochanteric Femur Fractures
View Large
Table 51-5
Subtrochanteric Femur Fractures
Common Adverse Outcomes and Complications
Malunion
Nonunion
Infection
X

Author’s Preferred Treatment for Subtrochanteric Femur Fractures

 
 

The author’s preferred treatment for all subtrochanteric fractures is a locked, trochanteric entry IM nail performed in a supine position on a fracture table as described above. This treatment method has demonstrated reliability in all patient populations presenting with a subtrochanteric fracture and, even if combined with a mini-open clamp-assisted reduction, is less invasive than plating techniques.

Summary, Controversies, and Future Directions in Subtrochanteric Femur Fractures

Subtrochanteric femur fractures represent a challenge to the treating surgeon secondary to the deforming forces that must be overcome to restore length, alignment, and rotation. The implant selected for fixation must also be able to withstand the high load demands inherent to this anatomic location. Current IM nail designs have been shown to reliably result in union in the overwhelming majority of cases. 
Plating techniques to address these fractures have recently undergone a short-lived resurgence, which was aided by locking screw technology; however, clinical results employing these techniques have fallen far short of theoretical benefits. Research directed at understanding these shortcomings will help lead to improved implants and techniques for future treatment of patients. 
Advancements in nailing will likely focus on percutaneous reduction instruments and various proximal locking options to optimize proximal fragment fixation. In addition, computer navigation shows promise with respect to reducing the incidence of varus and rotational malunions. 
Improvements in revision arthroplasty technique, especially with regard to diaphyseal-engaging modular, tapered, fluted stems may play a role in the treatment of subtrochanteric nonunion. Future research will likely showcase these stems as the implant of choice in treating the multiply operated subtrochanteric nonunion. 
Finally, the emergence of bisphosphonate-related subtrochanteric fractures, and the higher rate of complications associated with treating them, present issues that require vigilance as the incidence of bisphosphonate use has increased during the last decade. Dialogue and research efforts involving internists, endocrinologists, basic scientists, and orthopedic surgeons should continue to determine the best way to administer bisphosphonates so that both fragility fractures and the adverse complications of medications prescribed to prevent them are avoided. 

References

1.
Afsari A, Liporace F, Lindvall E, et al. Clamp-assisted reduction of high subtrochanteric fractures of the femur. J Bone Joint Surg Am. 2009;91(8):1913–1918.
2.
Banffy MB, Vrahas MS, Ready JE, et al. Nonoperative versus prophylactic treatment of bisphosphonate-associated femoral stress fractures. Clin Orthop Relat Res. 2011; 469(7):2028–2034.
3.
Barquet A, Mayora G, Fregeiro J, et al. The treatment of subtrochanteric nonunions with the long gamma nail: Twenty-six patients with a minimum 2-year follow-up. J Orthop Trauma. 2004;18(6):346–353.
4.
Brien WW, Wiss DA, Becker V Jr, et al. Subtrochanteric femur fractures: A comparison of the Zickel nail, 95 degrees blade plate, and interlocking nail. J Orthop Trauma. 1991;5(4):458–464.
5.
Collinge CA, Weber T, Watson JT, et al. Results of complex proximal femur fractures treated with locking proximal femur plates. 2012, Poster Presentation at the OTA Annual Meeting: Minneapolis Minnesota.
6.
de Vries JS, Kloen P, Borens O, et al. Treatment of subtrochanteric nonunions. Injury. 2006;37(2):203–211.
7.
Enocson A, Mattisson L, Ottosson C, et al. Hip arthroplasty after failed fixation of trochanteric and subtrochanteric fractures. Acta Orthop. 2012;83(5):493–498.
8.
Forward DP, Doro CJ, O’Toole RV, et al. A biomechanical comparison of a locking plate, a nail, and a 95° angled blade plate for fixation of subtrochanteric femoral fractures. J Orthop Trauma. 2012;26(6):334–340.
9.
French BG, Tornetta P 3rd. Use of an interlocked cephalomedullary nail for subtrochanteric fracture stabilization. Clin Orthop Relat Res. 1998;(348):95–100.
10.
Glassner PJ, Tejwani NC. Failure of proximal femoral locking compression plate: A case series. J Orthop Trauma. 2011;25(2):76–83.
11.
Grisell M, Moed BR, Bledsoe JG. A biomechanical comparison of trochanteric nail proximal screw configurations in a subtrochanteric fracture model. J Orthop Trauma. 2010; 24(6):359–363.
12.
Gugenheim JJ, Probe RA, Brinker MR. The effects of femoral shaft malrotation on lower extremity anatomy. J Orthop Trauma. 2004;18(10):658–664.
13.
Haidukewych GJ, Berry DJ. Nonunion of fractures of the subtrochanteric region of the femur. Clin Orthop Relat Res. 2004;(419):185–188.
14.
Isaacs JD, Shidiak L, Harris IA, et al. Femoral insufficiency fractures associated with prolonged bisphosphonate therapy. Clin Orthop Relat Res. 2010;468(12):3384–3392.
15.
Kinast C, Bolhofner BR, Mast JW, et al. Subtrochanteric fractures of the femur. Results of treatment with the 95 degrees condylar blade-plate. Clin Orthop Relat Res. 1989; (238):122–130.
16.
Kummer FJ, Olsson O, Pearlman CA, et al. Intramedullary versus extramedullary fixation of subtrochanteric fractures. A biomechanical study. Acta Orthop Scand. 1998; 69(6):580–584.
17.
Pai CH. Dynamic condylar screw for subtrochanteric femur fractures with greater trochanteric extension. J Orthop Trauma. 1996;10(5):317–322.
18.
Park-Wyllie LY, Mamdani MM, Juurlink DN, et al. Bisphosphonate use and the risk of subtrochanteric or femoral shaft fractures in older women. JAMA. 2011;305(8):783–789.
19.
Prasarn ML, Ahn J, Helfet DL, et al. Bisphosphonate-associated femur fractures have high complication rates with operative fixation. Clin Orthop Relat Res. 2012;470(8): 2295–2301.
20.
Prasarn ML, Cattaneo MD, Achor T, et al. The effect of entry point on malalignment and iatrogenic fracture with the Synthes lateral entry femoral nail. J Orthop Trauma. 2010; 24(4):224–229.
21.
Pugh KJ, Morgan RA, Gorczyca JT, et al. A mechanical comparison of subtrochanteric femur fracture fixation. J Orthop Trauma. 1998;12(5):324–329.
22.
Puhaindran ME, Farooki A, Steensma MR, et al. Atypical subtrochanteric femoral fractures in patients with skeletal malignant involvement treated with intravenous bisphosphonates. J Bone Joint Surg Am. 2011;93(13):1235–1242.
23.
Ricci WM, Schwappach J, Tucker M, et al. Trochanteric versus piriformis entry portal for the treatment of femoral shaft fractures. J Orthop Trauma. 2006;20(10):663–667.
24.
Robinson CM, Houshian S, Khan LA. Trochanteric-entry long cephalomedullary nailing of subtrochanteric fractures caused by low-energy trauma. J Bone Joint Surg Am. 2005;87(10):2217–2226.
25.
Sanders R, Regazzoni P. Treatment of subtrochanteric femur fractures using the dynamic condylar screw. J Orthop Trauma. 1989;3(3):206–213.
26.
Seinsheimer F. Subtrochanteric fractures of the femur. J Bone Joint Surg Am. 1978; 60(3):300–306.
27.
Starr AJ, Hay MT, Reinert CM, et al. Cephalomedullary nails in the treatment of high-energy proximal femur fractures in young patients: A prospective, randomized comparison of trochanteric versus piriformis fossa entry portal. J Orthop Trauma. 2006;20(4): 240–246.
28.
Thompson RN, Phillips JR, McCauley SH, et al. Atypical femoral fractures and bisphosphonate treatment: Experience in two large United Kingdom teaching hospitals. J Bone Joint Surg Br. 2012;94(3):385–390.
29.
Tomas J, Teixidor J, Batalla L, et al. Subtrochanteric fractures: Treatment with cerclage wire and long intramedullary nail. J Orthop Trauma. 2013;27(7):e157–e160.
30.
Weil YA, Rivkin G, Safran O, et al. The outcome of surgically treated femur fractures associated with long-term bisphosphonate use. J Trauma. 2011;71(1):186–190.
31.
Wieser K, Babst R. Fixation failure of the LCP proximal femoral plate 4.5/5.0 in patients with missing posteromedial support in unstable per-, inter-, and subtrochanteric fractures of the proximal femur. Arch Orthop Trauma Surg. 2010;130(10):1281–1287.
32.
Wiss DA, Brien WW. Subtrochanteric fractures of the femur. Results of treatment by interlocking nailing. Clin Orthop Relat Res. 1992;(283):231–236.
33.
Zickel RE. Subtrochanteric femoral fractures. Orthop Clin North Am. 1980;11(3):555–568.