Objective Summarize the biologic effects of Supartz FX for knee osteoarthritis (OA), the first worldwide clinically approved intra-articular (IA) hyaluronic acid (HA) product. Design To determine the mechanism of action from preclinical and clinical studies, a literature search was conducted of Supartz FX using academic databases from 1987 to 2016. Articles on Supartz FX that deal with its mechanisms of action were extracted, categorized, and reviewed. Results Supartz FX has 2 potential mechanisms of action: (1) biomechanical: IA Supartz FX directly improves the viscoelasticity and lubrication of synovial fluid; (2) physiologic: IA Supartz FX penetrates synovium and cartilage tissues to reach HA receptors on the surface of synoviocytes and chondrocytes. In synovium, suppression of gene expression in inflammatory mediators results in improved endogenous HA production, improved properties of synovial fluid, and reduction in pain. In cartilage, suppression of gene expression of collagenases and aggrecanases suppresses cartilage degeneration. Conclusion The net results of basic and clinical studies is that IA Supartz FX provides a more favorable biomechanical and functional environment in the knee joint. Hence, it is not only a lubricant but is also physiologically active. These actions may help explain both short- and long-term improvement in pain and function often achieved from IA Supartz FX in knee OA.
Keywords: Supartz FX; hyaluronic acid; knee osteoarthritis; mechanism of action.