The epidemiology of peripheral fractures.

Although much is known about hip fracture epidemiology, there are relatively little data regarding fractures at other peripheral sites. Epidemiological differences between fractures are important, since they imply that an understanding of the consequences and clinical expression of osteoporosis requires the study of many different fracture types. Recent data regarding the basic epidemiology of limb fractures among the elderly in industrialized countries have made some patterns clear. Fractures outside the hip are relatively common events, and before age 70 to 75, ankle and distal forearm fractures occur more commonly than fractures of the hip. Among the elderly, fractures at the most proximal and most distal ends of the limbs have the highest incidence. Thus, in the upper extremity, fractures of the proximal humerus and distal forearm are the most common, while in the lower extremity, those at the hip and ankle predominate. Outside the axial skeleton, females have higher rates for most fracture types, and at most fracture sites whites have higher rates than blacks. In each limb, the most proximal fractures tend to have the most pronounced age-related increases in risk.