[A clinical study on the development of the acetabulum after various treatment in congenital dislocation of the hip (author's transl)].

In the treatment of congenital dislocation of the hip, prognosis varies greatly according to the status of the development of the acetabulum. In most of the patients with osteoarthritis of the hip primary causes are found. In this series, 50% had congenital dislocation of the hip and 35% had acetabular dysplasia. In order to identify the conditions of hip joints in which the acetabular development can be expected from conservative treatment and to estimate the limit of age for indication of this treatment, the status of the development of the acetabulum was investigated after various treatment. This is expected to provide valuable data for the establishment of the method of treatment for cases without hope for the development of the acetabulum. According to the results, patients with acetabular angle of more than 30% at the age of 3 years have less possibility of normalization in the future and therefore active means for formation of the acetabulum should be considered in these patients. As such active means included are formation of the acetabulum through the pelvic osteotomy and the derotation-varus osteotomy are available in order to improve concentric position of the femoral head. It was also indicated that more favourable results could be obtained in patients who had undergone the pelvic osteotomy. The most favourable results were obtained in patients in whom both operations were used in combination. It was concluded from the results of the study that the best method is to perform the pelvic osteotomy first and to add the derotation-varus osteotomy as indicated.