1. Almost all patients with osteoarthritis of the hip who consult the surgeon do so because they wish to be relieved of pain. They all have limitation of movement in varying degrees but most of them will be either unaware of it or will have accepted it. What is more important, they would not have sought medical advice because of stiffness if there had been no pain. The primary objective of operative treatment must therefore be to relieve pain.

2. Displacement osteotomy will give substantial relief from pain in a high proportion of cases and the relief is lasting. Perhaps that explains why this operation, advocated by McMurray and Malkin twenty-five years ago, is being practised more widely than ever to-day while its competitors (neurectomy, capsulectomy, arthroplasty) have steadily diminished in popularity.

3. The disadvantages of the operation are all related to post-operative immobilisation in plaster, which may induce further stiffness of the hip, even to the extent of ankylosis, or stiffness and pain in the knee. These disadvantages may be overcome to a considerable degree by internal fixation followed by sling suspension and early active movement. But when, under anaesthesia, the range of hip flexion is reduced to 45 degrees or less, the operation is always liable to result in ankylosis, and it is wise in these circumstances to take this possibility into account and warn the patient beforehand.

1. Two cases of deposition of calcium on the outer side of the knee are described.

2. The condition is believed to be uncommon and does not appear to have been described before.

3. One case resolved with conservative treatment, the other after an operation at which the deposit was found in the tendon of popliteus.