Clinical and radiological studies were performed on 25 hips of 25 patients with rapidly destructive coxopathy within 3 years after the onset. The mean age at the time of onset was 68.3 years. Two patients were males, and the other 23 were females ; many patients were aged females. The mean Japanese Orthopaedic Association hip score for pain was 13/40 while that for the range of motion (flexion) was 9.4/12. Inspite of marked pain, the motion range was relatively good. The mean disease duration was 10.3 months in the group showing an increased blood sedimentation rate and 20.8 months in the group with a normal sedimentation rate, being shorter in the former showing positive inflammatory reactios. Hypertension was observed in 44%. Radiographic examination showed osteoporosis in all patients. According to Singh's classification, the disease duration was shorter in patients with advanced osteoporosis. The Center-Edge angle and Acetabular-Head Index as the acetabular covering rate were below the mean value in 65%, showing slight dysplasia of hip joint. Histopathological examination revealed exposure of eburnated bone on the surface of the capital lesion in many patients, but only slight proliferative changes. In the synovial membrane, villous hyperplasia and cell proliferation were observed in the surface layer in most of patients. Free fragments of the cartilage and bone were phagositized with nonspecific inflammatory findings in the deep layer.
rapidly destructive coxopathy