Transient osteoporosis of the hip.

We report four cases of transient hip osteoporosis studied between 1995 and 1997. All patients were men. The diagnosis was based on clinical symptoms, absence of abnormal laboratory tests, increased uptake in the femoral head and neck on Tc-99 bone scans and magnetic resonance imaging showing Oedema of the bone marrow. In three patients radiographs showed osteopenia of the head and neck of the involved femur, whereas no major radiographic changes were seen in the fourth patient. The clinical symptoms lasted 7 months and there was no recurrence after 8-24 months' follow-up.