Derotation osteotomy in the management of congenital dislocation of the hip.

From 1956 to 1965, congenital dislocation of the hip was treated in a standard manner in 191 cases. Reduction and plaster immobilisation was followed by a period in a Batchelor type plaster in full medial rotation. Femoral neck anteversion was then corrected by derotation osteotomy. In 95 children 117 hips were treated in this way and have been reviewed annually for 18 to 27 years. In 1983 they were assessed; there were 101 hips with good clinical results; radiologically, on a modified Severin scale, 62 were good, 39 were fair and 16 were poor. Derotation osteotomy proved to be the stimulus for growth of the acetabular roof in most cases; its safety, ease of performance and predictability suggest that it is superior to other methods of correcting the dysplasia.