[Disappearing hip--algodystrophy of the hip].

Algodystrophy of the hip--also characterized as disappearing hip, transient demineralization of the hip, neurotropic rheumatism of the hips, or osteolytic arthropathy of the hips--is a pseudoinflammatory disease entity with normal inflammatory parameters involving movement- and load-dependent pain and radiologically visible demineralization of the femoral head. The osteolysis may be so pronounced that the femoral head has become virtually invisible (disappearing hip). The wide spectrum of possibilities in differential diagnosis, including inflammatory hip diseases in particular, together with the rarity of "disappearing hip", often allow diagnosis only retrospectively if the condition has not been thought of from the outset. The usually spontaneous course without residues can be markedly shortened by calcitonin treatment, therapy with nonsteroid antirheumatic agents, or by prednisone treatment. We report 2 cases of "disappearing hip" with typical course treated at the Orthopedic Clinic of Olten Cantonal Hospital in the period 1980 to 1988.