When pain killers, exercise, and physical therapy have all failed, a medical technology called viscosupplementation can relieve knee pain caused by osteoarthritis. Viscosupplementation does not replace the need for thigh muscle strengthening, or for overweight patients to lose weight. There are currently two products available in Canada, Sodium Hyaluronate (Hyalagan) and Hylan G-F 20 (Synvisc). These products are made of a biopolymer of a synthetic polysaccharide substance called hyaluranan, which is made to possess elasticity and viscosity like that of young, healthy, synovial fluid. They are delivered through a series of injections, all one week apart, and work by adding "padding" to the joint as well as reducing inflammation and improving mobility. Pain relief appears in a few days, progresses over a few weeks, and often lasts several months. One of the concerns about viscosupplementation is that it is relatively expensive, at least more so than NSAIDs and cortisone injections. Unfortunately, most provincial drug plans do not cover viscosupplements, and it is difficult to predict who will gain long-term benefit (e.g. 3-6 months) versus short-term benefits (2-3 weeks) from the products.

Further reading

Adams ME, Atkinson MH, Lussier AJ, Schulz JI, Siminovitch KA, Wade JP, Zummer M. The role of viscosupplementation with hylan G-F 20 (Synvisc) in the treatment of osteoarthritis of the knee: a Canadian multicenter trial comparing hylan G-F 20 alone, hylan G-F 20 with non-steroidal anti-inflammatory drugs (NSAIDs) and NSAIDs alone. Osteoarthritis Cartilage 1995;3(4):213-25.