Intra-articular hyaluronan therapy

The hyaluronan in normal synovial fluid plays an important role in joint ho meostasis. It contributes to joint lubrication, buffers load transmission a cross articular surfaces, provides a renewed source of hyaluronan to joint tissues, and imparts antinociceptive and anti-inflammatory properties to sy novial fluid. In osteoarthritis, the molecular weight and concentration of hyaluronan in synovial fluid are diminished. This has led to the propositio n that removal of pathologic osteoarthritic synovial fluid and replacement with hyaluronan-based products that restore the molecular weight and concen tration of hyaluronan toward normal levels can have beneficial therapeutic effects. This form of treatment for osteoarthritis has been termed viscosup plementation. Within the musculoskeletal community there are diverse opinions, ranging fr om skepticism to acceptance, about viscosupplementation as a mainstream sym ptom-modifying osteoarthritis therapy. This review focuses on recent basic and clinical studies dealing with mechanism of action, symptomatic efficacy , safety, and disease modification, and places these studies in context wit h earlier studies. (C) 2000 Lippincott Williams & Wilkins, Inc.