disease-modifying effects, it may then be reasonable to consider their use early in cartilage injury or disease, before the onset of syntomatic OA. Additional well-designed randomized controlled trials with high methodological quality are needed to resolve the contin- ued uncertainty about the therapeutic effects of different types of hyaluronic acid products on osteoarthritis in various clinical situations and patient populations (Wang et al 2004). At the moment the Arthritis Foundation believes that while more studies are needed to determine the long-term results of such treatments, HA provides an option for people with knee OA who have not responded well to drug treatments or exercise and physical therapy. 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