Treatment of painful osteoarthritis of the knee with hyaluronic acid. Results of a multicenter Asian study.

Hyaluronic acid is a component of synovial fluid, in osteoarthritis (OA) and shows a change of property of hyaluronic acid especially its viscoelasticity causing degradation of the cartilage. Injection of hyaluronic acid into OA of the knee (Hyalgan 2 ml/wk for 4 doses) in international multicentres gave dramatic responses: decreased pain, increased mobility of the joint after 49 days of injections compared to a placebo (2 ml of normal saline) p<0.01.