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Fractures and Dislocations of the Hip


As the number of hip fractures continues to increase in the United States (with an estimated 458,000 to 1,037,000 hip fractures per year by 2050 in patients 45 years old or older), orthopaedic surgeons will be called on to help deal with this impending public health crisis. Although most hip fractures occur in the geriatric population, more and more young patients are surviving motor vehicle accidents and presenting with high-energy injuries about the hip. Hip fractures in these two populations can be very different, and an understanding of these differences will help determine the appropriate treatment to minimize morbidity and mortality and restore the patient to his or her preinjury functional status.

Femoral Neck Fractures

Fractures of the neck of the femur occur predominantly in the elderly, typically resulting from low-energy falls, and may be associated with osteoporosis. Fractures of the femoral neck in the young are a very different injury and are treated in very different ways. Femoral neck fractures in young patients typically are the result of a high-energy mechanism, and associated injuries are common. Most fractures of the femoral neck are intracapsular and may compromise the tenuous blood supply to the femoral head ( Fig. 55.1 ).This blood supply must also be understood for approaches to the proximal femur as well as implant placement. While the superior retinacular artery has been well described as being the main provider of perfusion to the femoral head, the inferior retinacular artery has more recently been shown to also provide significant perfusion and the anatomic course has been demonstrated to be consistent.

FIGURE 55.1, Blood supply to the femoral head.

Classification

Femoral neck fractures can be classified by the location of the fracture line (subcapital, transcervical, or basicervical [ Fig. 55.2 ]), the Garden classification, or Pauwels classification. The Garden classification ( Fig. 55.3 ) is the most commonly used classification system and is based on the degree of displacement:

  • Stage I: incomplete fracture line (valgus impacted)

  • Stage II: complete fracture line; nondisplaced

  • Stage III: complete fracture line; partially displaced

  • Stage IV: complete fracture line; completely displaced

FIGURE 55.2, Classification of femoral neck fractures by location: subcapital, transcervical, basicervical.

FIGURE 55.3, Garden classification of femoral neck fractures.

Stages III and IV can be differentiated radiographically by carefully scrutinizing the trabecular patterns of the femoral head and acetabulum. Stage III femoral neck fractures maintain contact between the femoral neck and femoral head, and the trabecular patterns between the head and acetabulum are no longer aligned. Stage IV fractures do not maintain contact between the femoral neck and femoral head, and the trabecular patterns between the head and acetabulum have realigned. Interobserver reliability between stages is low; however, most surgeons are able to differentiate between nondisplaced femoral neck fractures (stages I and II) and displaced femoral neck fractures (stages III and IV). A shortcoming of the Garden classification is that angulation and displacement in the sagittal plane are not considered.

The Pauwels classification ( Fig. 55.4 ) was initially described in 1935 in the German literature and was thought to describe the major forces present at the fracture site. The classification has been misquoted in the literature over the years, causing some confusion, but the basic premise remains: increasing verticality of the femoral neck fracture line is associated with increased presence of shear at the fracture site. The classification is based on the angle the fracture line makes in reference to the horizontal. The fracture line in a Pauwels type I fracture is between 0 and 30 degrees in reference to the horizontal, type II is between 30 and 50 degrees, and type III is more than 50 degrees ( Fig. 55.5 ). More recently, Collinge et al. reported significant comminution in 96% of femoral neck fractures with high Pauwels angles. The Pauwels classification is relevant because optimal treatment may vary with the Pauwels angle.

FIGURE 55.4, Pauwels classification of femoral neck fractures.

FIGURE 55.5, Radiograph (A) , CT scans ( B and C ), and clinical photograph (D) of high Pauwels angle femoral neck fracture.

Diagnosis

The diagnosis of a femoral neck fracture is based on history, physical examination, and radiographs. Most patients with femoral neck fractures give a history of a traumatic event, with the exception of patients who have stress fractures of the femoral neck. Also, many young patients with high-energy femoral neck fractures have associated injuries, including head injuries, and may not be able to give a history. The index of suspicion for a femoral neck fracture must be extremely high because the consequences of a missed femoral neck fracture can be disastrous. The physical examination typically reveals an extremity that is shortened and externally rotated. Standard anteroposterior pelvic and cross-table lateral views of the hip are necessary, and a traction internal rotation view often is helpful. The cross-table lateral view, while often difficult to obtain, is probably essential in enabling prediction of failure with fixation in Garden I and II femoral neck fractures. The entire femur should be imaged. MRI has become the imaging study of choice to evaluate occult femoral neck fractures. CT scans to evaluate femoral neck fractures, often available as part of the trauma work up (CT scan of the chest, abdomen, and pelvis), can yield useful information including degree of comminution.

Treatment

A satisfactory reduction is paramount in minimizing the complications associated with treatment of femoral neck fractures, including nonunion and osteonecrosis. “Radiographic” or “visual” reduction continues to be debated; however. studies that have associated reduction quality with outcomes are generally based on radiographs. A closed reduction can be attempted in every patient for whom internal fixation is planned. The Whitman technique involves applying traction to the abducted, extended, externally rotated hip with subsequent internal rotation. Reduction attempts should not be forceful and should not be repeated more than two or three times. Once reduction has been attempted, the angulation and alignment must be critically evaluated. The Garden alignment index ( Fig. 55.6 ) can be used to evaluate femoral neck angulation and alignment. The trabecular alignment pattern ( Fig. 55.7 ) is evaluated with both anteroposterior and lateral radiographs or fluoroscopy. On the anteroposterior image, the angle between the medial shaft and the central axis of the medial compressive trabeculae should measure between 160 and 180 degrees. An angle of less than 160 degrees indicates varus, whereas an angle of more than 180 degrees indicates excessive valgus. On the lateral image, angulation should be approximately 180 degrees and deviation of more than 20 degrees indicates excessive anteversion or retroversion. Interestingly, Liporace et al. reported a high percentage of retroversion of the femoral neck (approximately 20% of Caucasians in their series), and this relatively high frequency of retroversion must be considered in the care of not just femoral neck fractures but other fractures of the proximal femur and femoral shaft. Lowell et al. described the radiographic or fluoroscopic appearance of an anatomically reduced femoral neck as “shallow-S– or reverse-S–shaped curves” ( Fig. 55.8 ); these “curves” may be more useful than the Garden alignment index for intraoperative evaluation of alignment. We find using the fluoroscopic appearance of the contralateral uninjured hip useful intraoperatively as a reference for these “curves” as well as varus/valgus angulation.

FIGURE 55.6, Garden alignment index.

FIGURE 55.7, Anteroposterior radiograph shows angle between medial trabecular stream in femoral head and medial cortex of femoral shaft.

FIGURE 55.8, A , Concave outline of femoral neck meets convex outline of femoral head in “S” or reversed-“S” curve superiorly, inferiorly, anteriorly, and posteriorly. B, Failure of restoration of these “S” signs is indicative of nonanatomic alignment.

Operative Treatment

Most femoral neck fractures require operative treatment. Possible exceptions include stress fractures on the compression side of the femoral neck and femoral neck fractures in patients who are nonambulatory and comfortable or are too infirm for operative treatment.

Implant Choice

The choice of implant and operation is largely dependent on the patient’s physiologic age. Patients with displaced femoral neck fractures who are physiologically older are best treated with arthroplasty. Younger patients are treated with internal fixation. With hemiarthroplasty, controversy exists to some degree over the use of cemented or cementless stems, as well as unipolar or bipolar prostheses. Data from several studies indicate that many community ambulators may be better treated with THA than with hemiarthroplasty. A major concern with THA for femoral neck fracture is dislocation, which has led to an increased interest in using an anterior or anterolateral approach (see Chapter 1 , Techniques 1.63 and 1.65) when THA is done for treatment of a femoral neck fracture.

Fixation of Femoral Neck Fracture With Cannulated Screws

Technique 55.1

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    Place the patient supine on a fracture table. Attempt closed reduction with the Whitman or other reduction technique. We typically scissor the lower extremities (unaffected hip extended relative to the injured side), but a well-leg holder also can be used.

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    Fluoroscopically assess the quality of the reduction. If reduction is satisfactory, proceed with fixation.

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    We typically use three partially threaded screws (6.5, 7.0, or 7.3 mm) in an inverted triangle configuration ( Fig. 55.9A and B ).

    FIGURE 55.9, For fixation of femoral neck fractures, three partially threaded screws can be inserted in an inverted triangle configuration (A and B) . Four screws can be placed in a diamond configuration when significant comminution is present (C) . ( SEE TECHNIQUE 55.1. )

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    Use fluoroscopy in both planes to localize placement of the inferocentral wire. Make a skin incision extending 2 to 3 cm proximally. Split the fascia in line with the skin incision, and use a Cobb elevator to gently split the fibers of the vastus lateralis muscle longitudinally.

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    Place the inferocentral wire in perfect position on both views. Placing a guidewire along the anterior femoral neck can be helpful in determining appropriate anteversion. Make sure not to begin below the lesser trochanter and to continue proximally along the calcar. We use smooth or drill-tipped guidewires to optimize tactile feel and minimize cortical extrusion.

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    Once the first guide pin is in place, use a parallel guide to place the posterosuperior and then anterosuperior pins to obtain posterior and anterior cortical support in the femoral neck. The posterosuperior guidewire should not be above the equator on the anteroposterior view. The anterosuperior guidewire should be above the equator on the anteroposterior view. Advance the guide pins just short of the articular surface. Be very careful not to violate the articular surface.

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    To determine appropriate screw length, measure the length of the guide pin and subtract 5 mm. Self-drilling, self-tapping screws generally are used, but sometimes predrilling of the outer cortex is necessary in patients with dense bone. Washers are used where space permits.

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    A fourth screw (diamond configuration) may be used in patients with significant posterior comminution ( Fig. 55.9C ). Use extreme care if a fourth screw is used because of the possibility of being extraosseous if the screw is placed posteriorly.

Guide pins should be placed with the goal of obtaining femoral neck cortical support for screws. The femoral neck is not circular; it is more of an anterior-leaning ellipse. Zhang et al. warned of a cortical perforation risk of almost 20% in a two-dimensional 6.5-mm screw placement simulation ( Fig. 55.10 ). The risk of perforation was 6.7% posterosuperiorly and 10.7% anteroinferiorly, and the authors illustrated “risk zones” for screw placement. Concerns about cortical perforation have also been noted, specifically in regard to the posterosuperior screw placement in an inverted triangle configuration. They reported a 70% screw extrusion rate ( Fig. 55.11 ) for posterosuperior screw (6.5 mm) placement using fluoroscopy in a cadaver model.

FIGURE 55.10, SZ indicates the safe zone.

FIGURE 55.11, A, Anteroposterior and lateral fluoroscopic images showing contained screw. B, Stripped cadaver specimen with posterior-cranial screw breach with thread extrusion.

Care must be taken in the starting of guide pins on the lateral cortex because inaccurate passage of the pins (multiple attempts or attempts below the level of the lesser trochanter) has been associated with subtrochanteric femoral fractures. In a biomechanical model, screw configuration was shown to influence the occurrence of subtrochanteric femoral fracture. Femoral neck fractures fixed with an apex-distal configuration exhibited a greater load to failure (before subtrochanteric femoral fracture) than those fixed with an apex-proximal configuration. The concern of subtrochanteric femoral fracture, as well as the increased possibility of nonunion, was reported in a recent clinical study as well. Although a randomized trial suggested no difference between long (32 mm) and short (16 mm) threaded screws for femoral neck fractures, we attempt to maximize thread length proximal to the fracture line, but not crossing the fracture line, when compressing femoral neck fractures. Interestingly, Liu et al. suggested a redesign of screw thread length (26 mm) to accomplish this goal. Washers are used whenever possible because their use has been suggested to reduce the risk of failure, likely because of increased compressive forces generated when they are used.

Cannulated screw fixation can be done only after satisfactory reduction has been obtained. If satisfactory closed reduction cannot be obtained, open reduction, or arthroplasty in an elderly patient, is indicated. An inadequate closed reduction must not be accepted. An open reduction can be done through either a Watson Jones-approach (see Technique 1.67) or a modified Smith-Petersen approach (see Technique 55.2). Subcapital or transcervical femoral neck fractures can be better seen and more easily reduced through a modified Smith-Petersen approach; however, this approach does require a second incision for placement of fixation. A recent cadaver study supports increased anatomic exposure with the modified Smith-Petersen approach (with or without a rectus tenotomy) versus the Watson-Jones approach.

Open Reduction and Internal Fixation

Technique 55.2

(MODIFIED SMITH-PETERSEN)

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    Position the patient supine on a flat-topped or fracture table. A fracture table makes lateral fluoroscopy easier.

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    Make a longitudinal incision beginning at the anterior superior iliac spine and extending approximately 10 cm distally toward the lateral aspect of the patella.

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    Incise the fascia of the tensor fascia latae and develop the interval between the tensor fascia latae and the sartorius muscle. Cauterize ascending branches of the lateral femoral circumflex artery as they are encountered.

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    Identify and tag the direct head of the rectus femoris and then release it off the anterior inferior iliac spine if desired. Repair it at the conclusion of the procedure either directly (if stump has been left) or with a suture anchor.

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    Reflect the indirect head of the rectus femoris muscle from the capsule, along with the iliocapsularis muscle if present.

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    Perform a capsulotomy in the shape of a T, inverted-T, Z, or H. We most often use a T-shaped capsulotomy; however, a Z-shaped capsulotomy also is reasonable. The vascular anatomy of the proximal femur must be considered, and portions of the capsulotomy must be carefully extended (e.g., if a capsulotomy in the shape of an inverted T or H is made, posterior extension of the transverse limb at the base of the femoral neck should be avoided to prevent injury to the blood supply to the femoral head). Hohmann retractors can be placed within the capsule and used for gentle retraction, always being cognizant of femoral head perfusion.

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    Place a 5.0-mm Schanz pin in the proximal femoral diaphysis to control the distal segment and place a T-handle on the Schanz pin to aid in manipulation.

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    Insert two 2.0-mm threaded Kirschner wires into the head segment and use them as joysticks to reduce the fracture. We also have used a reduction clamp (Farabeuf) to gain compression across the fracture of the femoral neck, as described by Molnar and Routt ( Fig. 55.12 ).

    FIGURE 55.12, Reduction (Farabeuf) clamp can be used to gain compression across femoral neck fracture. A, Displaced fracture. B, Reduced fracture. SEE TECHNIQUE 55.2 .

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    Once satisfactory reduction is confirmed both visually and radiographically, insert cannulated screws (see Technique 55.1), screw–side plate (SSP) device with derotational screw, or proximal femoral plate.

Postoperative Care

Patients with high-energy femoral neck fractures are kept at touch-down (weight of leg) weight bearing for 10 to 12 weeks. Older patients are allowed protected weight bearing with a walker if their balance and other medical comorbidities allow. Patients who cannot safely ambulate are encouraged to mobilize to a chair to minimize pulmonary complications.

Controversy exists about the best method of fixation for displaced subcapital and transcervical femoral neck fractures, and there are strong advocates of both cannulated screws ( Fig. 55.13 ) and compression hip screws . The recent FAITH (Fixation using Alternative Implants for the Treatment of Hip Fractures) randomized controlled trial showed no difference in reoperation rates between cancellous screws and SSP in the treatment of low-energy femoral neck fractures in patients older than 50 years. Subgroup analysis did suggest a potential advantage of SSP devices in displaced fractures, basicervical fractures, and in smokers, although there was a higher rate of osteonecrosis in patients treated with SSP devices (9% vs. 5%). Based on study protocol, none of the patients treated with SSP devices had supplemental fixation such as a derotational screw. Biomechanical studies suggest that a compression hip screw coupled with a derotational screw ( Fig. 55.14 ) is stronger than three cannulated screws in the treatment of unstable basicervical femoral neck fractures. A retrospective clinical study comparing fixation devices for Pauwels type III femoral neck fractures found no definitive evidence indicating the optimal fixation device. There was a higher nonunion rate with cannulated screws than with fixed angle devices (dynamic hip screw, cephalomedullary nail, dynamic condylar screw); however, this difference was not statistically significant. Biomechanical data suggest that a proximal femoral locking plate may be superior to both cannulated screws and a compression hip screw in a Pauwels type III femoral neck model, but clinical studies have not been encouraging. Berkes et al. reported a high incidence of catastrophic failure with proximal femoral locking plates. A different design of plate has shown improved results compared with cannulated screws; this design allows some controlled shortening. We typically reserve use of proximal femoral locking plates for fractures with significant femoral neck comminution ( Figs. 55.15 and 55.16 ). The Targon dynamic proximal femoral locking plate (Aesculap AG, Tuttlingen, Germany) ( Fig. 55.17A ), which has been used in Europe for more than a decade with generally favorable results, is currently not available in United States. The Conquest dynamic proximal femoral locking plate (Smith & Nephew, Memphis, TN) ( Fig. 55.17B ) is a similar option; however, clinical data currently are lacking.

FIGURE 55.13, Cannulated screw fixation of displaced femoral neck fracture after open reduction.

FIGURE 55.14, Displaced femoral neck fracture (A) , in this case ipsilateral to femoral shaft fracture, fixed with compression hip screw and derotational screw (B) .

FIGURE 55.15, Axial CT scan of femoral neck fracture with significant posterior femoral neck comminution.

FIGURE 55.16, Preoperative radiograph (A) and axial (B) and coronal (C) CT scans of a femoral neck fracture with posterior femoral neck comminution with extension into the greater trochanter. D , United fracture after fixation.

FIGURE 55.17, Dynamic locking constructs for proximal femoral fractures. A, Targon FN (Aesculap B. Braun Medical Inc, Tuttlingen, Germany). B, CONQUEST FN (Smith & Nephew, Memphis, TN).

Other options include a trochanteric lag screw and medial buttress plating. A trochanteric lag screw for high Pauwels angle femoral neck fractures is supported by biomechanical data; however, a recent clinical series specifically using this technique did not have favorable results.

The technique for placement of a compression hip screw is described in the section on intertrochanteric femoral fractures (see Technique 55.4). Care must be taken with placement of a large diameter lag screw in patients with nonosteoporotic bone, and consideration should be given to routinely using a tap as well as placing a derotational screw.

Femoral neck shortening ( Fig. 55.18 ) appears to be common after fixation of femoral neck fractures. Shortening of more than 1 cm was reported to occur after 42% of Garden I fractures and 63% of Garden II fractures fixed with cannulated screws. The importance of femoral neck length in influencing functional outcome has been emphasized in several reports. Femoral neck shortening was associated with pain and decreased mobility in a study of over 500 patients with femoral neck fractures treated with the Targon dynamic femoral locking plate. The mean age of patients in this study was 76.1 years. Zlowodzki et al. retrospectively evaluated the effect of femoral neck shortening on functional outcome in 70 patients with healed femoral neck fractures, 64% of which were nondisplaced intracapsular fractures. All patients were treated with screw fixation, and 69 of 70 had acceptable reductions according to the Garden alignment index. Interestingly, 46 (66%) of the 70 patients healed with shortening of more than 5 mm and 27 (39%) had more than 5 degrees of varus. The primary outcome measure, the SF-36 physical functioning score, correlated with the degree of femoral neck shortening, suggesting that femoral neck shortening negatively impacts functional outcome. Similarly, Slobogean et al. reported decreased functional outcomes (Harris Hip Score, Timed Up and Go, SF-36 Physical Component Summary) in patients younger than 55 years of age (mean, 43.7 years) who had shortening of 10 mm or more after treatment of a femoral neck fracture with multiple cancellous screws.

FIGURE 55.18, Significant femoral neck shortening after treatment of minimally displaced femoral neck fracture with partially threaded cannulated screws. A, Intraoperative fluoroscopic anteroposterior view. B, Anteroposterior radiograph revealing significant femoral neck shortening.

Boraiah et al. reported treatment of 54 intracapsular femoral neck fractures with anatomic reduction, intraoperative compression, and length-stable implants. Various open reduction techniques were used depending on fracture pattern and physiologic age. Intraoperative compression was achieved before placement of a dynamic hip screw (or dynamic helical hip screw) and fully threaded screws. The overall union rate was 94%, with an average shortening of the femoral neck of 1.7 mm. The average 36-Item Short Form Health Survey (SF-36) physical functioning score was 42, and the Harris Hip Score was 87. The Bodily Pain subscore of the SF-36 correlated with the “abductor lever arm” (distance from the center of the femoral head to a tangential line along the greater trochanter). Patients with greater differences in the abductor lever arm between the fractured and unaffected sides had lower Bodily Pain subscores. Weil et al. reported a small series demonstrating minimal shortening after the treatment of femoral neck fractures with fully threaded screws; 23 of 24 fractures were classified as Garden I or II. There was no statistically significant difference in complication or reoperation rates when compared to a historical control treated with partially threaded screws. Larger series supporting this technique currently are lacking in the literature, and at least one study reported high complication rates.

Only slight changes in technique are necessary to stabilize femoral neck fractures at length. Obviously, the reduction is paramount. Using length-stable implants in fractures that are not well reduced may result in nonunion. Potentially, the goals of union and maintenance of femoral neck length can both be achieved. Closed reduction of displaced fractures can be attempted, followed by open reduction through either a Smith-Petersen or Watson-Jones approach if closed reduction fails to obtain an anatomic reduction. In older patients and fractures with less displacement, more limited open reductions can be done if needed with the use of ball-spike pushers, Cobb elevators, and Kirschner wires to obtain anatomic reductions. After reduction has been obtained, partially threaded cannulated screws can be placed for compression across the fracture site. Once adequate compression is achieved, the cannulated screws are replaced one by one with fully threaded screws with washers. If a compression hip screw is to be used, such as for a high Pauwels angle femoral neck fracture, a guide pin is placed perpendicular to the fracture line, and a partially threaded cannulated screw is inserted, followed by the SSP device. The partially threaded screw is then changed to a fully threaded screw ( Fig. 55.19 ). Two fully threaded screws also can be used if patient’s femoral neck anatomy will allow. As previously noted, large series demonstrating the effectiveness of these techniques are lacking in the literature.

FIGURE 55.19, In an attempt to minimize femoral neck shortening, partially threaded screw used for compression is changed to fully threaded screw. A, Radiograph at time of injury. B and C, After operative reduction and fixation.

Femoral neck shortening also may lead to prominent implant placement. Implant removal was the most frequent reoperation (24%) reported in 796 young patients after treatment of femoral neck fractures. Zielinski et al. reported a similar rate of reoperation for implant removal (23%), but implant removal generally had a positive impact on patients’ quality of life. Surgeons and patients should be aware of the possibility of femoral neck fracture after implant removal.

Outcomes and Complications

Failure of Fixation

Internal fixation may fail because of many factors, including inadequate reduction, poor implant selection or position, nonunion, osteonecrosis, and infection. Determining the cause of fixation failure is extremely important in planning revision surgery. In young patients, early recognition of inadequate reduction or poor implant selection or position can be treated with revision open reduction and internal fixation ( Fig. 55.20 ) and femoral neck nonunions or malunions can be treated with valgus intertrochanteric osteotomy. Femoral neck nonunion, malunion, and osteonecrosis in elderly patients can be treated with THA. Infection after the treatment of femoral neck fractures can be quite problematic. The goal is to suppress the infection with debridement and culture-specific antibiotics, maintaining the hardware until union at which time it is removed. Hardware failure with infection requires hardware removal and possibly resection arthroplasty. Occasionally, total hip arthroplasty can be done after implant failure with infection but only in a staged fashion and after infection has been eradicated.

FIGURE 55.20, Malreduction of femoral neck fracture resulting in varus (A) and apex posterior (B) deformity. C and D, After revision open reduction and internal fixation.

Nonunion and Osteonecrosis

Nonunion ( Fig. 55.21 ) and osteonecrosis ( Fig. 55.22 ) are two major problems that lead to revision surgery after treatment of intracapsular femoral neck fractures. In a meta-analysis of 18 studies involving younger patients (ages 15 to 50 years) with femoral neck fractures, the overall incidence of osteonecrosis was 23% and the incidence of nonunion was 9%. The 564 patients in these studies included those with both displaced and nondisplaced intracapsular femoral neck fractures. In a series of 73 femoral neck fractures in patients between the ages of 15 and 50 years treated at a single institution, Haidukewych et al. found an overall frequency of osteonecrosis of 23% and nonunion of 8%. Osteonecrosis developed in 27% of displaced fractures and 14% of nondisplaced fractures. Thirteen patients (18%) had conversion to arthroplasty; 11 of these arthroplasties were done purely for osteonecrosis. Initial fracture displacement and the quality of radiographic reduction were found to affect results. In another series including 62 Pauwels type III femoral neck fractures, osteonecrosis developed in 11% and nonunion in 16%. The average age of patients in this series was 42 years (range 19 to 64 years). The higher nonunion rate in this study is likely a result of the difficulty of treating higher Pauwels angle femoral neck fractures.

FIGURE 55.21, Nonunion of femoral neck fracture. Anteroposterior radiograph (A) and CT scan (B) . C, Union after fixation with blade plate.

FIGURE 55.22, Osteonecrosis after treatment of femoral neck fracture: ( A ) anteroposterior radiograph, ( B ) axial CT scan, and ( C ) coronal CT scan.

Osteonecrosis continues to be a problem after femoral neck fractures, even nondisplaced fractures. In fact, higher intracapsular pressures have been demonstrated with nondisplaced femoral neck fractures than with displaced fractures. Routine capsulotomy is controversial. Capsulotomy probably is most effective in Garden types I and II fractures in which the capsule may not be torn or completely torn and tamponade may be a major cause in the development of osteonecrosis. We usually perform capsulotomies in young patients with nondisplaced femoral neck fractures and only occasionally do so in the geriatric population. Although there is no conclusive study proving that capsulotomy decreases the frequency of osteonecrosis, it can be done quickly and safely and may reduce the risk of osteonecrosis.

Fluoroscopically Guided Capsulotomy of the Hip

Technique 55 . 3

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    After fixation of the femoral neck fracture, prepare a no. 10 scalpel blade by placing an approximately 2-cm strip of Ioban around the blade/handle junction to decrease the likelihood of dissociation of the blade from handle within the body.

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    Through the lateral incision made for fixation with cannulated screws, compression hip screw, or proximal femoral locking plate, using tactile feel and fluoroscopic guidance, advance the scalpel along the anterior femoral neck with the blade directed inferiorly.

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    Once the femoral head is encountered, rotate the blade 90 degrees and withdraw the scalpel with a posterior directed force to complete the capsulotomy.

Christal et al. showed in a cadaver series that fluoroscopically guided capsulotomy is safe and effective at decreasing intracapsular pressure. Dissections of the cadavers after capsulotomy found that the average distances from the femoral artery and lateral most branch of the femoral nerve were 40.3 and 19.5 mm, respectively. The minimal distances in individual cadavers were 36 mm from the femoral artery and 15 mm from the lateral most branch of the femoral nerve. Intracapsular pressure was substantially decreased after capsulotomy.

A meta-analysis of 106 reports of displaced femoral neck fractures in older patients (65 years or older) reported overall rates of osteonecrosis and nonunion of 16% and 33%, respectively. The rate of reoperation within 2 years ranged from 20% to 36% after internal fixation, which was higher than after hemiarthroplasty. Interestingly, a recent randomized controlled trial revealed a 20% major reoperation rate for nondisplaced femoral neck fractures treated with screws in patients 70 years of age or older. Although there was no difference in Harris Hip Scores between those treated with screws and those with hemiarthroplasty, patients with hemiarthroplasty were more mobile and had a lower rate of major reoperations.

Arthroplasty

The decision to proceed with fixation or arthroplasty depends on fracture characteristics and physiologic patient age. Displaced femoral neck fractures in physiologic younger patients (<65 years of age) generally should be treated with anatomic reduction and stable internal fixation. Displaced femoral neck fractures in most older patients should be treated with arthroplasty. The role of arthroplasty for geriatric patients with nondisplaced femoral neck fractures deserves further exploration. A high-quality meta-analysis that included nine randomized trials showed that arthroplasty substantially reduced the risk of revision surgery compared with internal fixation in the treatment of displaced femoral neck fractures in patients 65 years of age or older. Arthroplasty, however, was associated with greater blood loss, longer operative time, and more frequent infections. Hudson et al. found a higher rate of reoperation after internal fixation than after hemiarthroplasty in patients older than 80 years but did not find a difference in reoperation rates in patients between 65 and 80 years of age. In a randomized trial, Rogmark et al. compared internal fixation and arthroplasty for treatment of displaced femoral neck fractures in ambulatory patients aged 70 years or older. Failure, defined as early fracture displacement, nonunion, osteonecrosis with collapse, or infection, occurred in 43% of patients treated with internal fixation and in 6% of those treated with arthroplasty at 2 years. A follow-up study of the same cohort of patients at 10 years revealed that these results were stable over time: at no point in time did patients with successful internal fixation display better outcomes in regard to hip pain or mobility than did patients with successful arthroplasty. The American Academy of Orthopaedic Surgeons Clinical Practice Guideline for Management of Hip Fractures in the Elderly (2014) states “Strong evidence supports arthroplasty for patients with unstable (displaced) femoral neck fractures” ( Table 55.1 ).

TABLE 55.1
American Academy of Orthopaedic Surgeons Clinical Practice Guideline for Management of Hip Fractures in the Elderly
Modified from https://www.aaos.org/CustomTemplates/Content.aspx?id=6395 .
Fracture/Treatment Consideration Recommendation/Comment Strength of Recommendation
Stable (nondisplaced) femoral neck fracture Operative fixation Moderate
Unstable (displaced) femoral neck fracture Arthroplasty Strong
Unipolar vs. bipolar Similar outcomes in unstable (displaced) femoral neck fractures Moderate
Hemi vs. total hip arthroplasty Total hip arthroplasty more beneficial in properly selected patients with unstable (displaced) femoral neck fractures Moderate
Cemented femoral stems Cemented femoral stems preferred in arthroplasty for femoral neck fracture Moderate
Surgical approach Higher dislocation rates with posterior approach for arthroplasty in treatment of displaced femoral neck fractures Moderate
Stable intertrochanteric fractures Sliding hip screw or cephalomedullary device Moderate
Subtrochanteric or reverse obliquity fractures Cephalomedullary device Strong
Moderate recommendation—evidence from two or more “moderate” strength studies with consistent findings, or evidence from a single “high” quality study for recommending for or against the intervention.
Strong recommendation—evidence from two or more “high” quality studies with consistent findings for recommending for or against the intervention.

Once the decision has been made to proceed with arthroplasty, several controversial issues still need to be considered: type of arthroplasty (hemiarthroplasty or total hip arthroplasty [THA]), unipolar or bipolar (if hemiarthroplasty has been chosen), cemented or uncemented femoral stem, and surgical approach. Total hip arthroplasty is superior to hemiarthroplasty ( Fig. 55.23 ) for displaced femoral neck fractures in active, physiologically older patients without significant comorbidities. Many studies have identified several potential benefits of THA over hemiarthroplasty, including superior functional outcome scores, decreased pain, improved ambulation, and lower reoperation rates. A disadvantage of THA appears to be a slightly higher dislocation rate. A change in approach (direct anterior) may alleviate some of the dislocation concerns with THA. In community ambulators with a longer than 5-year life expectancy, THA generally is a better option than hemiarthroplasty. Those with a short life expectancy, significant medical comorbidities, or cognitive impairment are better served with hemiarthroplasty. If hemiarthroplasty is chosen, unipolar or bipolar heads appear to yield similar results. Moderate evidence appears to favor cemented over noncemented stems.

FIGURE 55.23, Anteroposterior (A) and lateral (B) radiographs show displaced left femoral neck fracture. C, After total hip arthroplasty.

Interestingly, only 21% of respondents to a recent survey reported that the 2014 Clinical Practice Guidelines (CPG) led to changes in their practice. The two changes most frequently cited were increased use of THA and cemented stems. Not surprisingly, arthroplasty-trained surgeons were more likely than trauma-trained surgeons to use THA in the two femoral neck fracture examples contained in the survey.

Although the CPG highlight recommendations for geriatric fracture care, financial data suggest that arthroplasty rather than fixation should be considered for patients younger than 65 years. THA was found to be a cost-effective option for displaced femoral neck fractures in patients older than 54 years. The age at which THA was cost-effective decreased with increasing comorbidities. THA was cost-effective for patients older than 47 years with mild comorbidity (Charlson Comorbidity Index [CCI] 1 or 2) and for patients older than 44 years with multiple comorbidities (CCI ≥ 3). Complications are more frequent after THA for failed internal fixation than after THA for acute femoral neck fracture.

Basicervical Femoral Neck Fractures

Basicervical femoral neck fractures are extracapsular femoral neck fractures, and much controversy exists regarding their treatment. These fractures are rare, with some estimates as low as 1.6% of all hip fractures. They are often misclassified as well, sometimes being grouped with transcervical femoral neck fractures and other times with intertrochanteric femoral fractures. Su et al. showed that basicervical femoral neck fractures are more unstable than intertrochanteric femoral fractures. Both biomechanical and clinical studies have concluded that these fractures are not ideally treated with cannulated screws. Watson et al. reported failure in six of 11 patients with basicervical neck fractures treated with intramedullary nailing. Five of the six failures were associated with screw cut-out despite all six having a tip-apex distance less than 22 mm (mean, 17.4 mm). None of these patients had a derotational screw placed. Another study suggested better outcomes with intramedullary nailing than with a screw and side-plate device (SSP) for basicervical femoral neck fractures. Authors of a recent biomechanical study were unable to determine the optimal implant for basicervical femoral neck fractures. Different modes of failure were noted between intramedullary nails and SSP devices with a derotational screw. While all of the SSP failures involved screw cut-out, only one of 18 intramedullary nails failed with screw cut-out. Seventeen failed either rotationally or with medial trochanteric wall migration. The failure mode in this biomechanical study is obviously different from the failure mode outlined by Watson et al. Hopefully, future studies will evaluate intramedullary nails with an additional screw, either independent or part of the proximal interlocking mechanism. There also may be a role for arthroplasty in physiologically older patients with a basicervical femoral neck fracture.

Intertrochanteric Femoral Fractures

Classification

Many classifications of pertrochanteric and intertrochanteric femoral fractures have been proposed over the years. Boyd and Griffin initially described four types of pertrochanteric femoral fractures in 1949 ( Fig. 55.24 ):

    • Type 1: Fractures that extend along the intertrochanteric line

    • Type 2: Comminuted fractures with the main fracture line along the intertrochanteric line but with multiple secondary fracture lines (may include coronal fracture line seen on lateral view)

    • Type 3: Fractures that extend to or are distal to the lesser trochanter

    • Type 4: Fractures of the trochanteric region and proximal shaft with fractures in at least two planes

FIGURE 55.24, Boyd and Griffin classification of trochanteric fractures.

Probably the most useful classification of intertrochanteric femoral fractures is the AO/OTA classification ( Fig. 55.25 ):

    • 31A1: Fractures are not comminuted (single fracture line extending medially).

    • 31A2: Fractures have increasing comminution (separate lesser trochanteric fragment).

    • 31A3: Fractures include reverse obliquity, transverse, or subtrochanteric extension patterns.

FIGURE 55.25, AO classification of trochanteric fractures. Group A1, simple two-part fracture; group A2, fracture extends over two or more levels of medial cortex; group A3, fracture extends through lateral cortex of femur distal to vastus ridge.

Each group contains subgroups to further describe the characteristics of each fracture. The AO/OTA classification has been very useful in evaluating the results of treatment of intertrochanteric femoral fractures and allowing comparisons among reports in the literature.

Treatment

Nonoperative treatment of intertrochanteric femoral fractures is rare but may still have a role in nonambulatory patients in whom adequate pain control can be achieved without surgery. Internal fixation is appropriate for most intertrochanteric femoral fractures. Optimal fixation is based on the stability of the fracture. The mainstay of treatment of intertrochanteric femoral fractures is fixation with a SSP device ( Fig. 55.26 ) or intramedullary device ( Fig. 55.27 ).

FIGURE 55.26, Fixation of intertrochanteric fracture with compression hip screw. A, Preoperative anteroposterior radiograph. B and C, After fixation.

FIGURE 55.27, Fixation of intertrochanteric fracture with Gamma nail. A, Preoperative radiograph. B, After fixation.

Treatment With Screw–Side Plate Devices

Compression or dynamic hip screws are a good option for the treatment of stable intertrochanteric femoral fractures (AO/OTA 31A1 and many 31A2 fractures), particularly in patients with lower preinjury functional status. The implant cost is less with SSP than with intramedullary nails, and the technique of placement of a SSP is familiar to most experienced orthopaedic surgeons; however, orthopaedic surgeons who have completed their training more recently may not be as familiar with the procedure.

Screw–Side Plate Fixation of Intertrochanteric Femoral Fractures

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