© Reed GroupA femoral neck fracture is a hip fracture in which the neck of the thigh bone (femur) is partially or completely broken. Femoral neck fractures may occur as a result of a fall or motor vehicle accident, or they may occur spontaneously because of a disease process such as osteoporosis. Stress fractures can result from repetitive mechanical stress or structural defects in the bone that make it weak or brittle. Femoral neck fractures in the elderly may occur spontaneously or following low-velocity trauma; in young adults, femoral neck fracture usually is caused by high-velocity trauma. Conditions that predispose to femoral neck fracture include diabetes, osteoporosis (particularly in postmenopausal women), softening of the bones (osteomalacia), cancer that has metastasized to the bone, rheumatoid arthritis, neurological disease, previous hip fracture, hyperparathyroidism associated with severe renal disease and maternal history of hip fracture. A complete fracture is described as the femoral neck no longer being intact. A displaced fracture of the femoral neck, usually caused by trauma, refers to a condition where the bone has been moved out of its original position resulting in the two adjoining bone fragments failing to line up. Another potential scenario for a displaced fracture is a femoral neck bone fragment having rotated about its axis. If a stress fracture goes unrecognized, it can progress to a complete fracture and displace. Fractures of the femoral neck are divided into four types according to the Garden system, which describes fractures according to their degree of completeness and displacement. Garden Type I fracture is incomplete or twisted (valgus impacted); Type II is complete but not displaced; Type III is complete and partially displaced; and Type IV is complete and totally displaced. Type I fractures are considered stable, while the other classes of fractures are considered unstable. An impacted fracture, in which the surfaces are crushed together, must be distinguished from a nondisplaced fracture. A nondisplaced fracture has no impaction and no inherent instability.
Risk: Distance runners and ballet dancers are at particular risk for developing a stress or incomplete fracture of the femoral neck, as are the elderly. Other risk factors for femoral neck fracture include low body weight, prior radiation treatment (irradiation), sedentary lifestyle, impaired vision and poor balance that results in falls, and previous hip fracture. Athletic training errors, such as a sudden increase in the quantity or intensity of training or the introduction of a new activity, also are risk factors.
Incidence and Prevalence: It is estimated that 250,000 hip fractures occur in the US each year (Malanga). This figure is expected to double within the next 30 years (Auron-Gomez). Incidence of hip fracture in individuals aged 65 and older is 818 per 100,000. Women are affected 2 to 3 times more often than men (Auron-Gomez). Stress fractures of the femoral neck are more common in women and comprise 5% to 10% of all stress fractures (Malanga); the prevalence of hip fracture, regardless of location, is highest among women of European ancestry, followed by men of European ancestry, women of African ancestry, and men of African ancestry (Malanga).
Source: Medical Disability Advisor