[Natural courses of coxarthrosis and indication of rotational acetabular osteotomy].

Many factors may influence the development of the secondary osteoarthritis which might have originated from congenital dislocation, subluxation, or acetabular dysplasia of the hip. Accurate prediction of the development of osteoarthritis may be essential to initiate a proper treatment for those patients. We studied whether various acetabular indices could serve as the parameters in predicting the future degenerative changes. Our findings indicated that those indicators did not suggest the future course of the development of osteoarthritis. However, osteoarthritis may appear in younger ages when CE angle is extremely low. And the assessment of the hip congruity has an important factor in predicting any osteoarthritic changes. In those cases, the deranged anatomy of the hip must be corrected to prevent further development of osteoarthritis. There is a wide range of choices for the operative treatment of the dysplastic hip. We are doing the uniquely designed acetabular osteotomy since 1968. This procedure, rotational acetabular osteotomy, is basically the same as Wagner's spherical acetabular osteotomy, or Eppright's dial osteotomy, in which a circumacetabular osteotomy is also done. This operation is indicated for those patients whose hips show such incongruity that degenerative arthritis is inevitable, or in the early stage of degenerative arthritis. We discussed the indications of rotational acetabular osteotomy, by comparing clinically and roentgenologically with the cases in which natural courses were followed up for a long time.