Viscosupplementation is a procedure in which a thick fluid called hyaluronate is injected into the knee joint.  it is thought that hyaluronate will improve the lubricating properties of the synovial fluid, reduce the pain from osteoarthritis of the knee, improve mobility, and provide a higher and more comfortable level of activity. If you have tried all other nonsurgical treatment methods and your pain continues to limit your activities, viscosupplementation may be an option.