Epidemiology of traumatic and nontraumatic osteonecrosis.

In reviewing the epidemiology of traumatic and nontraumatic osteonecrosis the only common denominator appears to be that of circulatory compromise. Causative mechanisms seem to be quite distinct. A number of factors may predispose to postfracture hip necrosis, i.e. the type of fracture, the quality of reduction and union of the fracture. For postdislocation necrosis, causative factors include the type of dislocation as well as the timing and nature of the reduction. For nontraumatic osteonecrosis, an array of consistently associated systemic disorders appears to be largely linked by frequent lipid elevations. Alcoholism and corticosteroid use account for the bulk of cases and there is consistent predisposition to males and bilateral involvement. Multifocal lesions attest to the systemic basis for this form of necrosis.