The pathophysiology of osteoarthritis and the implication of the use of hyaluronan and hylan as therapeutic agents in viscosupplementation.

Osteoarthritis (OA) is characterized by several pathological events, including a progressive erosion of the articular cartilage (particularly the weight bearing areas of the joint), synovial inflammation, which may contribute to disease progression, and changes in the lubricating properties of the synovial fluid (SF). We discuss the pathological features that may be involved in the progression of OA, and the implications of the restoration of the viscoelastic properties of the SF (viscosupplementation) as a therapeutic modality for the treatment of OA.