As the elderly population grows, the number of hip fractures continues to increase. The elderly have weaker bone and are more likely to fall due to poorer balance, medication side effects, and difficulty maneuvering around environmental hazards. Clinicians in many fields are involved in caring for patients with hip fractures and should be familiar with the basic assessment and management of these injuries.

This topic review will discuss the major types of hip fractures, including basic anatomy, fracture classification, and clinical and radiographic assessment. The details of surgical treatment are beyond the scope of this review. Prevention of hip fractures, preoperative assessment and the prevention and management of common medical complications associated with hip fractures are all discussed separately.

Worldwide, the total number of hip fractures is expected to surpass 6 million by the year 2050. A total of 310,000 individuals were hospitalized with hip fractures in the United States (US) alone in 2003, according to data from the US Agency for Healthcare Research and Quality, accounting for 30 percent of all hospitalized patients. Approximately one-third (101,800) of fracture patients went on to receive a hip replacement. The estimated cost for treatment is approximately $10.3 to 15.2 billion a year in the US.

Hip fractures substantially increase the risk of death and major morbidity in the elderly. One-year mortality rates have ranged from 12 to 37 percent in these patients, but may be declining. Approximately one-half of patients are unable to regain their ability to live independently. A meta-analysis of prospective studies found the relative hazard for mortality during the first three months following a hip fracture to be 5.75 (95% CI 4.94-6.67) in older women and 7.95 (95% CI 6.13-10.30) in older men. Although it decreases over time, the increased risk of death likely persists, according to this review and other studies. However, one large prospective case-control study found no increased risk of mortality after the first year following a hip fracture among women 70 years or older.

A large review of hip fractures in the US found that femoral neck and intertrochanteric fractures occur with approximately the same frequency in patients between the ages of 65 and 99 years. Intracapsular (ie, femoral neck) fractures occur about three times more often in women. The highest rates were found among white women. Intertrochanteric extracapsular fractures also occur in a 3:1 female to male ratio. Subtrochanteric fractures show a bimodal distribution (20 to 40 years and over 60 years).

Isolated trochanteric fractures occur more often in young, active adults between the ages of 14 and 25. Eighty-five percent of less severe trochanteric avulsion fractures occur in patients under 20 years of age. Trochanteric fractures in elderly patients usually result from direct trauma (eg, fall), but can be associated with pathologic injury (eg, fracture through bone metastases).

Issues related to the timing of surgical repair of hip fractures and perioperative mortality and morbidity are reviewed separately.

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Katherine M Walker, MD

Causes and Risk Factors

Elderly people are at a high risk for falling, the usual traumatic event that leads to hip fractures. “They fall because they lose their coordination. They have difficulty with their eye sight and they have difficulty with their balance, and they become weak,” says Dr. Charles A. Peterson, an orthopedic surgeon at Seattle Orthopaedic and Fracture Clinic. “When they fall, they tend to have a higher frequency of fractures due to osteoporosis and weaker bones.”

The risk factors for suffering a broken hip are numerous, including:

  Osteoporosis: This disease causes bones to become weaker, making them more susceptible to fracture. In the U.S., an estimated 10 million individuals already have osteoporosis, and 80% of those affected are women. In this population, hip fractures can occur during simple weight-bearing activities.
  Sex: Women lose bone density more quickly than men due to a decrease in estrogen levels after menopause begins.
  Heredity: Small-boned, slender-framed people; Caucasians; and Asians have an increased risk of suffering from osteoporosis.
  Nutrition: Poor nutrition in childhood increases hip-fracture risk. Eating disorders such as anorexia nervosa and bulimia damage bones.
  Tobacco and alcohol use: Smoking and drinking too much can lead to bone loss.
  Medications: Taking four or more medications at a time or taking any psychoactive medications are risk factors for falling.
  Home environment: Throw rugs and electrical wires are tripping hazards, as are a lack of stair railings and grab bars, unstable furniture, and poor lighting.
  Medical conditions: The following conditions can increase the risk of hip fractures, either through bone loss or by increasing the risk of falling: endocrine disorders, such as type 1 diabetes; gastrointestinal disorders; rheumatoid disorders; prolonged bed rest or immobility; nervous system disorders such as Parkinson’s disease or multiple sclerosis; dementia; and depression.