Transient osteoporosis of the hip.

Osteoporosis in a painful hip is usually a sign of inflammation or tumor. There exists, however, a self-limited clinical entity that presents with pain in the hip and where the only roentgenological manifestation is osteoporosis. Eight patients with this disease are described: five men and three women, ranging in age from 29 to 50 years. In four patients, the onset of disease was related to sprain, pregnancy, or delivery. Laboratory analyses and the clinical course of the disease excluded inflammation or a neoplasm as the cause. All patients fully recovered with 12 month, with no sequelae. The etiology of the disease remains unknown.