The pain in primary osteoarthritis of the knee. Its causes and treatment by osteotomy.

1. Some results of a clinical investigation of patients with osteoarthritis of the knee are described. 2. The different varieties of pain which occur in osteoarthritis are detailed. 3. A sub-group of patients with primary osteoarthritis of the knee is described. In this group "venous" pain predominated; the venographic appearances are typical, and in a large proportion of cases the veins outside the bone are manifestly abnormal. 4. It is suggested that venous congestion within the bone results from extra-osseus vein disturbances, and leads to congestive bone pain and to progressive joint degeneration. 5. The mechanism by which osteotomy produces relief of pain is analysed and discussed. 6. A simple procedure which reproduces some of the benefits of osteotomy is described.