Careful examination and evaluation of the patient with a hip fracture-dislocation must be made to identify all other injuries sustained during the traumatic event, including the head, spine, abdomen, and extremities. Rectal, perineal, and vaginal examinations should be made to rule out open fractures. Neurovascular considerations directly related to the dislocation warrant immediate and emergency consideration. The superior gluteal artery may be lacerated during this injury, and examination for sciatic, obturator, and femoral nerve injury should be made. Hip dislocations are considered a medical emergency, and after ruling out contraindications such as femoral neck fractures, closed reduction with the patient under anesthesia should be performed as soon as possible to diminish the risk of avascular necrosis (AVN) of the femoral head, as well as sciatic nerve injury. AVN is more likely to occur in hips that are not relocated within 6 hours of injury.7 Evaluation and documentation of the sciatic nerve before and after reduction are recommended because of the common injuries of the sciatic nerve during dislocation. As many as 30% of posterior hip dislocations are associated with sciatic nerve injuries, typically involving the peroneal branch of the sciatic nerve, which could result in foot drop.8 Another postsurgical complication that may arise is heterotopic ossification (HO), with a reported incidence as high as 64%. A higher incidence of HO has been associated with an anterior surgical approach.9
Acetabular fractures are serious albeit rare injuries, with a reported incidence of approximately 3 in 100,000 annually.10 In younger populations, these injuries are associated with high-energy traumatic events, such as motor vehicle accidents. Fractures of the acetabulum in older populations are generally caused by lower-energy trauma associated with falls from a standing height. The incidence of these fractures in the older population is increasing.11
The acetabulum has been described as being supported between the anterior and posterior columns of the innominate bone (Fig. 11-2). The anterior column consists of the anterior wall of the acetabulum, the anterior ilium, the superior pubic ramus, and the iliopectineal ramus. The posterior column is made up of the posterior wall and dome of the acetabulum, the ischial tuberosity, and the quadrilateral plate of the ilium. Classification and treatment of these injuries are based on an understanding of these columns.
The Letournel classification of acetabular fractures classifies the injury relative to the anatomic features of the fracture (Fig. 11-3). These fractures are divided into two types of fractures: elementary types and associated types. The elementary types consist of isolated fractures found in the anterior wall, anterior column, posterior wall, and posterior column of the ischium, as well as transverse fractures. The associated types of fractures cover combined regions and are subclassified as follows: posterior column and posterior wall fractures, posterior wall and transverse fractures, T-shaped fractures, anterior column and hemitransverse fractures, and fractures involving both columns.
Plain radiographs, specifically anteroposterior pelvis and Judet views, are recommended for identifying the presence of these fractures, whereas computed tomography (CT) scans provide accurate assessment of fracture anatomy and character.5 An understanding of the type of trauma that caused the injury can provide valuable information on the possibility of other potential comorbidities associated with the trauma, as well as any preexisting comorbidities that may influence management choices. If the patient has no associated hip dislocation, treatment of acetabular fractures is not considered an emergency; however, surgical treatment should be performed within the first 7 days after injury.5 This approach affords the trauma team time to make the patient physiologically stable and ready for surgery. Traction, a common practice following hip dislocation, may be applied through a pin in the distal femur with approximately 5 kg of weight. Traction may also be used during the surgical procedure.
Acetabular fractures with less than 2 mm of displacement may be treated nonoperatively if joint congruency remains good and the joint is stable. Displaced acetabular fractures are treated by internal fixation. The goal of surgical treatment is to provide good stability in the acetabulum to allow for early range of motion and good congruency between the femoral head and acetabulum. Internal fixation is preferred to percutaneous fixation because of the difficulties in achieving accurate reduction and estimating the appropriate depth of screw penetration to avoid intraarticular insult with external fixation. The choice of surgical approach varies with the characteristics of the fracture, other comorbidities, and the experience of the surgeon, although these fractures are typically reduced with lag screws and held in place with neutralization plates (Fig. 11-4).
If the hip joint is considered stable after the surgical procedure, rehabilitation following acetabular fracture involves early restoration of hip joint range of motion. Because of weight-bearing strain on the acetabulum, the patient should be non–weight bearing for 6 weeks and partially weight bearing for an additional 6 weeks. During this time, rehabilitation should also consider any comorbidities, such as head injury, spinal injuries, and other orthopedic trauma.5 Weight-bearing considerations in nonoperative management should be based on the location of fracture site, assessment of fracture site healing, bone mass, and other comorbidities associated with the individual patient. HO should be considered if the patient is complaining of hip pain during the postoperative period, because a relatively high incidence of HO is reported in these populations.
Acetabular fractures in older adults occur from low-energy trauma and are usually complicated by comorbidities that may have predisposed the patient to this injury initially. A common example of this is the presence of osteoporosis when combined with a more active lifestyle. Acetabular fractures in patients older than 60 years of age typically display anterior column displacement and roof impaction along with comminution of the quadrilateral surface of the ilium.11 Management of these injuries in older adults considers the status of all the body’s systems as much as the fracture site itself. Figure 11-5 contains more detailed information.
Femoral Head Fractures
Femoral head fractures are rare, with an incidence between 5% and 15% of all posterior hip dislocations.12 Several classifications have been described for a femoral head fracture, and the Pipkin classification is the most widely used. The Pipkin classification considers the location of the fracture within the femoral head, as well as any other fractures that may be present in a different portion of the femur or involvement of the acetabulum (Fig. 11-6). The diagnosis is made initially by radiographs, and fracture-dislocation of the hip can be viewed on a trauma anteroposterior pelvis radiograph.
A hip fracture-dislocation is considered an orthopedic emergency and should be managed initially by closed reduction. Reduction that is delayed longer than 6 hours after injury is associated with an increased risk for AVN of the hip. CT scan should be obtained after closed reduction to assess the reduction and evaluate for intraarticular comminution. If fracture fragments are found, they can be managed by either surgical excision or fixation. A fragment that is large enough to allow for internal fixation should be fixed. Smaller fragments found on the non–weight-bearing portions of the femoral head can be excised without consequence to outcome. If the hip is unable to be reduced, or if a femoral neck fracture is also present, an emergency open reduction is performed.
The goals of the definitive management of a femoral head fracture are to reduce the femoral head, thus leaving good alignment of the hip joint, and clear any bony fragments from the joint. Most femoral head fractures are managed surgically; however, a Pipkin type I fracture may be managed nonsurgically if good alignment with closed reduction is achieved and the CT scan confirms that no other bone fragments are interposed within the joint. The risk of osteonecrosis with delayed surgical treatment warrants open reduction in the absence of a CT scan or delay of imaging greater than 6 hours.
For Pipkin type III fractures, the femoral neck must be surgically reduced and fixed first. Then the femoral head fracture can be managed according to the reduction achieved by fixation of the femoral neck. If the femoral head fragment is still displaced, surgical reduction or excision will be performed based on the location and size of the fragment. Pipkin type IV fractures are managed by fixation of the acetabulum and the femoral head. The approach is determined by the location of the acetabular fracture.
Typically, it is recommended that the patient bear partial weight (equal to the weight of the limb) on the involved side for 8 weeks. After 8 weeks, a progression toward full weight bearing should begin. Decisions on weight-bearing progression should be made according to healing, as evidenced by imaging (CT-directed pelvic oblique radiograph) and the overall medical status and function of the patient. If all fragments are removed and no other surgical fixation is performed, the patient may be managed as weight bearing as tolerated immediately. If a posterior surgical approach is used, initial postoperative precautions for range of motion of the hip include no hip flexion greater than 90 degrees and no hip adduction or internal rotation.
Rehabilitation should begin immediately, to assist the patient in gaining mobility and function to allow for an expedient and safe transition home. If, during the course of rehabilitation, hip pain worsens and joint mobility becomes more limited, AVN of the femoral head may be suspected. The incidence of osteonecrosis of the femoral head at 2 years has been reported at 11%.13
Femoral Neck Fractures
Fractures of the femoral neck account for almost half of all hip fractures and are most commonly found in older populations in association with falls.14 Femoral neck fractures do occur in younger populations (>50 years of age) and may be divided into two groups, with different mechanisms of injury. Femoral neck fractures in patients younger than 40 years of age are typically caused by high-energy trauma, such as motor vehicle accidents. Another group of younger patients between the ages of 40 and 50 years may sustain these fractures after lower-energy traumatic events, typically a fall. Fractures in younger populations associated with low-energy trauma typically are associated with significant medical comorbidities and a higher rate of alcohol dependency.15 Femoral neck fractures are considered intracapsular injuries because the joint capsule encompasses the femoral head and neck and anchors to the distal end of the femoral neck. Three ways to manage these fractures are recommended: closed reduction with internal fixation, open reduction with internal fixation, or hip arthroplasty. The choice of definitive treatment depends on the characteristics of the individual patient. Physiologically young patients who demonstrate high levels of activity, good bone health, and few comorbidities are managed differently from physiologically old patients, who are physically inactive and have poor bone health and multiple comorbidities. Differences in fracture patterns and the expected level of activity after injury pose very different implications for proper choice of definitive care.
Femoral Neck Fractures in Younger Patients
Initial management of these fractures in younger populations is considered an emergency, to reestablish blood supply to the femoral head, thus minimizing the risk of AVN. However, when reviewing the literature comparing AVN incidence with the timing of surgery, no associations can be made. In addition, timing of surgical treatment has no relationship with the incidence of nonunion.
In one report of hip fractures, populations younger than 65 years of age had a relatively higher incidence of pathologic fractures (11%) than did populations older than 65 years of age (1.4%).3 Of the younger population, 18% of the fractures were associated with patients who had a history of alcohol abuse. AVN is a concern in the younger patient with a femoral neck fracture. A metaanalysis investigating displaced femoral neck fractures in younger patients (aged 15 to 50 years) found the overall incidence of AVN to be 22.5%. No differences in the incidence of AVN were observed between groups undergoing surgical treatment within 12 hours of injury and groups receiving treatment more than 12 hours following injury. Prospective data demonstrate, at the 2-year mark, no differences in incidence of AVN in these populations when surgical treatment was performed before or after a 48-hour period after injury.
The relationship of different fixation devices and the presence of AVN or nonunion and overall outcome have not been investigated in younger populations. The choices of hardware for femoral neck fractures vary and may include compression screws, dynamic fixed angle devices, static fixed angle devices, and locked plates.
The Pauwels classification is the most commonly used classification system to describe femoral neck fractures (Fig. 11-7). Classification is based on the angle of the fracture line relative to a horizontal line drawn from the iliac crest. Possessing a more vertical orientation, a Pauwels type III fracture has an increased risk for nonunion as well as AVN, and careful consideration of the forces placed on these fractures during rehabilitation activities is required. Although justification for the use of fixed-angle implants can be made from a biomechanical perspective in treatment of these shear force–type fractures, no advantage has been shown over the use of multiple compression screws.16 Nonunion has been associated with poor screw fixation placement and with the presence of a posterior comminution.17,18 Although an increase in intracapsular pressure is associated with femoral neck fractures, no benefit has been demonstrated when capsular decompression has been performed.19
Femoral Neck Fractures in Older Patients
Outcomes using nonoperative management of femoral neck fractures in older adults show significantly higher incidence of comorbidities (e.g., pneumonia, thromboembolic events, decubitus ulcers) and nonunion than in patients who underwent surgical fixation.20,21 The timing of surgery is important for the management of hip fractures in older adults. Delay of surgical treatment for more than 24 hours is associated with significantly higher mortality rates at the 30-day and 1-year postoperative marks (Table 11-1). No differences in mortality rates were found with delayed versus nondelayed surgery in patients who had significant medical comorbidities requiring preoperative treatment. This evidence supports the preoperative management of these comorbidities, even if it delays the surgical procedure.22
Surgical Timing in Hip Fractures in Older Adults
|Author||Study Design||Level of Evidence||Number||Summary|
|Zukerman et al, 1995*||Prospective observation||B||367||Surgical delay >48 hr doubled 1-year mortality (hazard ratio, 1.76)|
|Moran et al, 2005†||Prospective observation||B||2,660||Fit for surgery patients at presentation and surgical delay >4 days demonstrated increased 90-day (hazard ratio of 2.25; 95% CI: 1.2-4.3) and 1-yr mortality rates (hazard ratio, 2.4; 95% CI: 1.45-3.99)|
|Bottle and Aylin, 2006‡||Prospective observation||B||129,522||Delay in surgery >24 hr associated with increased in-hospital death odds ratio 1.39 (95% CI: 1.34-1.44), and when comorbidities were controlled, odds ratio fell to 1.27 (95% CI: 1.23-1.32)|
|Radcliff et al, 2008§||Prospective observation||B||5,683||Surgical delay of >4 days after admission associated with an increased risk of death within the first 30 days (odds ratio, 1.29; 95% CI: 1.02 to 1.61)|
|Shiga et al, 2008¶||Metaanalysis||B||257,367||Surgical delay of >48 hr increased 30-day and 1-year mortality rates by 41% (odds ratio, 1.41; 95% CI: 1.29-1.54) and 32% (odds ratio, 1.32; 95% CI: 1.21-1.43)|
The Garden classification system is most commonly used for femoral neck fracture classification in older patients (Fig. 11-8). Treatment options include internal fixation, hemiarthroplasty, and total hip arthroplasty (THA). Internal fixation has higher risk of nonunion (>30%) in patients with osteoporosis.23 Even if union is successfully achieved by fixation, varus collapse and impaction of the neck have been found in 64% and 39% of patients, respectfully.20,24 The presence of both impaction and varus collapse of the femoral neck is associated with poorer outcomes and predicts the need for an assistive device to assist with ambulation. THA is associated with higher blood loss and infection rates, and the incidences of surgical revision and progressive increase in pain are higher in patients undergoing internal fixation than with arthroplasty; higher costs are associated with internal fixation than with arthroplasty.25,26 Because of these concerns, internal fixation is considered only for patients who are young, have good bony integrity, and have a Garden type I fracture.
Callaghan and associates21 proposed a patient-related algorithmic approach to treatment. Their algorithm suggests that nondisplaced fractures should be managed with closed reduction and surgical fixation with screws. A displaced fracture in a younger patient is managed with open reduction and internal fixation. A displaced fracture in a physiologically older patient with good cognitive functioning can be managed with THA. Blomfeldt and colleagues27 compared outcomes between hemiarthroplasty and THA in the management of femoral neck fractures and found superior outcomes in the THA group that continued to strengthen at the 4-year mark. Keating and associates23 found superior outcomes in the THA group when comparing THA with hemiarthroplasty and internal fixation. These investigators also investigated the cost associated with each procedure and found that, although cost was initially the least in the fixation group, overall cost was much less in the THA group after all associated complications were managed in the internal fixation group. A patient demonstrating cognitive impairments would be managed with a hemiarthroplasty because of the concerns of a high incidence of hip joint dislocation (32%) following THA in cognitively impaired older populations, which is a much higher incidence than THA performed in cognitively intact populations.25,26,28–32