[Isolated decalcifying algodystrophy of the hip].

Transitory demineralization of the hip, a special form of reflex sympathetic dystrophy, is a rare condition. It should however be distinguished from more severe conditions such as tuberculosis or neoplastic bone disease. The typical symptoms are illustrated from 3 personally observed cases. The patients, usually men between the ages of 30 and 50 years or women in the last months of pregnancy, suffer severe mechanical pain in the hip, with limping and weakness. They usually need crutches for walking. Clinical examination of the hip reveals only slight restriction of passive movements. The erythrocyte sedimentation rate may be slightly elevated. Bone scan discloses hypercaptation, while other laboratory tests are negative. A few weeks after onset of symptoms, pelvic X-rays show extreme demineralization of the femoral head. On the other hand, the joint space and bony contours remain intact. The prognosis is excellent and the symptoms disappear after a few months or after delivery.