Supartz and the similar drugs Hyalagan and Synvisc are synthetic versions of hyaluronic acid, the normal lubricant in the knee. The exact mechanism of how these drugs work when injected into the knee is unknown, but they may stimulate the cartilage to grow. It is difficult to predict who will respond. I tell my patients that the overall response is about 50%, with patients with less severe disease on x-ray doing better. There are some who do absolutely great while others get no reponse. The risk of the injections is very low (although admittedly the injections are no fun) and thus patients are often willing to try. It is not a cure and when there is a response, it can last from 9-12 months.
About Alan Matsumoto, M.D.
Part-time Faculty, Division of Rheumatology
Johns Hopkins University