Hip Fractures

HIP FRACTURES

Hip fractures are one of the most devastating and costly problems commonly faced by the older population. More than 300,000 people sixty-five years of age and older are hospitalized each year for hip fractures in the United States, and about one-quarter of these people will not survive more than a year because of the fracture or its complications. Of those who do survive, most experience major reductions in their levels of function and ability to walk, and a sizable minority (15 to 25%) will be living in long-term care institutions at the end of one year. Looked at longitudinally, by their ninth decade one of three women and one of six men will have suffered a hip fracture.

Hip fractures usually result from two interacting processes: a fall or other dramatic event resulting in direct impact to the greater trochanter (upper part) of the femur (thigh bone); and an underlying weakness in the bone—usually from osteoporosis. Each of these processes has underlying risk factors that had been reasonably well studied. For example, the leading risk factors for falls in older adults include muscle weakness, gait and balanced disorders, decreased overall functional status, vision impairment, cognitive impairment, and medication side effects. Also important are the presence of hazards in the environment, such as icy pavements or objects on the floor. Risk factors for osteoporosis include having a firstdegree relative with osteoporosis, smoking, physical inactivity, alcohol abuse, low level of calcium in the diet, low sunlight exposure, early menopause, certain drugs (e.g., hyperparathyroidism, thyrotoxicosis, myleoma, chronic liver disease, malabsorption syndrome).

Most attempts to prevent hip fractures have focused on reducing the two underlying causes and their risk factors. Controlled clinical trials of measures to reduce falls have shown promising effects from multifactorial risk assessments combined with targeted interventions such as exercise programs and environmental inspection and modification. Exercise programs have been particularly well studied, and the greatest fall-reducing benefits have come from programs that include programs that include strengthening exercise (e.g., progressive weight training) and balance training(e.g., Tai Chi exercises). Taken together, these interventions have been shown to reduce fall rates significantly, in the range of from 10 to 30 percent.

Controlled trials addressing the second major underlying process behind hip fractures, osteoporosis, have similarly shown positive results in strengthening bone and, in some studies, in reducing fracture rates through treatment with a variety of medications such as estrogen, calcium, vitamin D, and bisphosphonates. However, these interventions also provide only a partial protective effect in fracture reduction, again in the range of from 10 to 30 percent. Clearly, reducing the risk of falls and osteoporosis has only been part of the solution to preventing hip fractures, and new effective approaches are still needed.

One such promising approach is the use of special hip protectors made from cushioning material or high-impact plastic to dissipate the shock. Such protectors have been the subject of several studies. In 1993, J. B. Lauritzen found a 53 percent lower rate of hip fractures in nursing homes where hip protectors were used. Even more impressive was that none of the people who experienced a hip fracture had actually been wearing a hip protector at the time of fracture. In 2000, a major confirmatory controlled trial from Finland appeared that studied elderly subjects living both in nursing homes and in the community. In this study there was a 54 percent lower rate of hip fracture in intervention group subjects as compared to the control group. The authors also compared fracture rates among fallers in the intervention group who were wearing and not wearing their hip protectors and found an 84 percent lower rate of hip fracture per fall among protector wearers. Another study of hip protectors showed that hip protectors improve self-confidence in frail individuals and may lead to improved mobility and function. Based on these studies, hip protectors should be strongly considered by individuals at increased risk for hip fracture (i.e., persons with osteoporosis and fall risk factors such as impaired gait or balance, weakness, and previous falls).

Treatment approaches for hip fractures usually involve surgery for internal fixation of the fracture or replacement of all or part of the hip joint. The choice of procedure depends on the type of fracture (e.g., sub-capital, femoral neck, intertrochanteric, subtrochanteric) and surgical risks of the patient. Early mobilization and active rehabilitation is crucial to minimize complications and maximize the chance of a good functional outcome. However, because many older individuals suffering hip fractures are frail to begin with, and have a relatively high surgical risk, there remains a high rate of surgical complications, lengthy and difficult rehabilitation periods, and long-term functional impairments. Prevention is clearly preferable to treatment, and as described above, many preventive avenues are available.

Laurence Rubenstein

(see also: Aging of Population; Geriatrics; Gerontology; Osteoporosis )

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