Abstract
1. The problem of instability of reduction in congenital dislocation and congenital subluxation of the hip has been studied and it has been concluded that the basic cause of this instability is the abnormal direction in which the entire acetabulum faces.
2. An operation, innominate osteotomy, has been designed to correct the abnormal direction of the entire acetabulum in children over the age of eighteen months. The principle of innominate osteotomy is redirection of the acetabulum so that the reduced dislocation or subluxation, which previously was stable only in a position of abduction and flexion, is rendered stable in the functional position of weight bearing.
3. The operative technique, and the pre-operative and post-operative management are described.
4. The indications for innominate osteotomy are outlined and the advantages of the operation are enumerated.
5. The early results of innominate osteotomy are very encouraging.
