Chapter 273: Hip and Femur Injuries

INTRODUCTION AND EPIDEMIOLOGY

Injuries to the hip and femur are common, occurring most often in the elderly population secondary to falls. Hip fractures are a significant and costly public health concern. Age, race, and gender are important risk factors for hip injuries; the incidence is more than two times greater in women than in men.¹

Morbidity and mortality from hip and femur fractures are due to complications from prolonged immobilization, with venous thromboembolism being the most common complication. Patients with hip fracture have a five- to almost eightfold increased risk of all-cause mortality in the first 3 months after the injury, and increased mortality persists for years afterward. Another significant portion of patients will have markedly decreased functional capacity. Advanced age, male gender, and comorbidities all increase mortality risk following hip fracture.²

This chapter discusses the diagnosis and ED management of fractures of the hip and proximal femur, fractures of the femoral shaft, and anterior and posterior hip dislocations. Fractures involving the femoral condyles are discussed in chapter 274, Knee Injuries.

ANATOMY AND PATHOPHYSIOLOGY

For purposes of this chapter, we define the hip as the anatomic region including the head and neck of the femur to 5 cm distal to the lesser trochanter. The femoral shaft is the portion of the femur distal to the lesser trochanter, down to but not including the femoral condyles.

The hip is a ball-and-socket joint formed by the femoral head and the acetabulum. The fibrous capsule that surrounds the joint on all sides is quite strong, attaching proximally at the acetabulum and distally on the intertrochanteric line on the anterior surface. The joint capsule is weakest posteriorly where it attaches to the femoral neck. The femoral head and shaft are connected at the obliquely angled femoral neck. Blood is supplied to the femoral head mainly from the medial and lateral femoral circumflex arteries that form an extracapsular ring with branching retinacular arteries in the joint capsule. Therefore, intracapsular fractures can compromise blood supply to the femoral head. Less important blood supply includes branches of the obturator and gluteal arteries, with a small contribution from the foveal artery at the ligamentum teres.

Hip fractures are classified as intracapsular (femoral head and neck) or extracapsular (trochanteric, intertrochanteric, and subtrochanteric). See Figures 273-1 and 273-2 and Table 273-1. The prognosis for successful union and restoration of normal function varies considerably with the fracture type. Most fractures occur in older patients with osteoporosis or other bony pathology secondary to systemic disease. Younger patients are more likely to have femoral shaft fractures or hip dislocation secondary to high-energy trauma.