Hip fractures cause a significant degree of morbidity and mortality in elderly persons. With the progressive increase in the number of elderly adults in the United States, a concurrent upsurge in hip fractures is likely. Beneficial preventive measures include exercise, calcium and vitamin D supplementation, and newer drugs, such as bisphosphonates, which prevent osteoporosis. Most hip fractures occur as a result of falling sideways and not from compression. This mechanism of injury directly impacts the greater trochanter at the proximal femur. Kannus and colleagues recently investigated whether an external hip protector would help prevent fractures in elderly adults who sustain a fall.

Potential members of the study were identified at 22 community-based health care centers with geriatric long-stay facilities. Men or women who were at least 70 years of age and ambulatory, but with at least one identifiable risk factor for hip fracture, were eligible. Risk factors for hip fracture included a previous fall or fracture, impaired balance or mobility, use of a walking aid, cognitive impairment, impaired vision, poor nutrition or a disease or medication known to predispose to falls. For each eligible subject, the study identified two control persons who would not wear a hip protector. The hip protector (length, 19.0 cm; maximal width, 9.0 cm; maximal height, 4.5 cm) consists of two convex shields that are worn in pockets of a stretchy undergarment (see accompanying figure). The shield is anatomically designed to absorb some force of a fall and shunt the energy of the impact away from the greater trochanter to the surrounding soft tissues. The primary outcome variable was fracture of the hip or the proximal femur.

A total of 653 patients were enrolled in the hip-protector group, and 1,148 patients were enrolled in the control group. Seventy-eight percent of the patients were women, and the mean age was 82 years. During the follow-up period, there were 67 hip fractures in the control group, but only 13 in the hip-protector group. This translates to a rate of hip fractures of 46 versus 21.3 per 1,000 person-years, respectively. Two persons in the hip-protector group had pelvic fractures compared with 12 in the control group. In the hip-protector group, four subjects had a hip fracture (among 1,034 falls) while wearing the shield compared with nine patients (among 370 falls) who sustained a fracture while not wearing the hip protector. This translates to 0.39 fractures per 100 falls with the protector versus 2.43 fractures per 100 falls without it. The number of persons needed to treat for one year to prevent a single hip fracture was 41, and the number of persons needed to treat for five years to prevent one fracture was eight.

The authors conclude from this study that the risk of hip fracture in elderly persons can be greatly reduced by the use of a hip-protector device. The hip protector may also decrease the risk of pelvic fractures.