Bone/Muscle Changes Following Hip Fracture in Older White Women

Hip fracture is a major public health problem, with striking consequences for the older patient, her family and the health care system. More than 350,000 persons over age 65 will fracture a hip in the United States during the coming year at an estimated annual cost of over $12 billion; by 2040, over 650,000 hip fractures will occur annually in this group. Between 18-33% of older hip fracture patients die within one year of their fracture, depending upon the specific population studied. Most surviving hip fracture patients experience reduced mobility and lose their ability to function independently. As many as 45% of those who are community dwelling at the time of their fracture are discharged to institutions post-hospitalization, and 15-25% remain institutionalized for a year post-fracture. Further, significant strain is observed in over a third of family caregivers as long as a year post-fracture. Depending upon the population studied and function being assessed, an estimated 25-75% of those who are independent before their fracture can neither walk independently nor achieve their previous level of independent living within a year following their fracture and 10- 20% of those who sustained a hip fracture can expect to have another osteoporotic fracture within two years.

This protocol consists of two components related to the recovery after hip fracture (described below):

EXERCISE INTERVENTION TRIAL. With few exceptions, which are restricted primarily to studies of comprehensive in-patient rehabilitation, little systematic attention has been given to evaluating strategies for improving functioning, bone, and muscle post-hip fracture. Strategies that have been shown to improve bone, muscle, and function in older persons who have not fractured a hip may be useful if applied to persons following hip fracture. Exercise is one of the strategies that have received considerable attention. Exercise training in older adults also has beneficial effects on bone density, muscle strength, and physical functioning, as well as cardiovascular fitness, and risk reduction for falls and fractures. An exercise program that combines weight-bearing and resistance exercises can increase bone mineral content in postmenopausal women. Little information is available on whether a home-based exercise program can be used to achieve similar benefits compared to a more structured, on-site exercise program. This issue is particularly relevant in older, frail women who have sustained a hip fracture because many are unable and unwilling to travel to exercise facilities.

Results of the studies of exercise are instructive of potential benefits for older persons following hip fracture. Most of the work to date has been restricted to relatively healthy, select samples of older persons who have been recruited into rigorously controlled randomized experiments. Hence, while they are efficacious in benefiting a select group of older persons, it is not known whether these interventions will be accepted by a frail older population which has become suddenly disabled by a hip fracture, nor is it known whether these interventions will be beneficial to this group which is losing bone, muscle and function at an accelerated rate.

Because losses in BMD following hip fracture place these women at greater rise of subsequent fracture and may delay or prevent full recovery of ambulatory ability, it is important to optimize fracture healing and prevent loss of bone. One therapeutic option for these patients that may be effective is to increase physical activity through exercise.