1. The various surgical procedures in common use for the treatment of the osteoarthritic hip are briefly reviewed and compared with the operation of replacement of both the acetabulum and head of the femur by a metal prosthesis, that is, a complete artificial hip joint.

2. The development, description and technique of insertion of this artificial hip joint are given in detail.

3. The results of the first fifty cases of this operation show a success rate of over 90 per cent. The few failures are analysed in detail. The revision procedure has been the insertion of another artificial hip joint.

4. The essential details necessary for success are stressed and the indications and aims of the operation given.