Hyaluronan, the name of the substance in Synvisc, is secreted by cells in the cartilage of joints. Hyaluronan is one of the major molecular components of joint fluid, and it gives the joint fluid, also called synovial fluid, its viscous, slippery quality. The high viscosity of synovial fluid allows for the cartilage surfaces of joints to glide upon each other in a smooth fashion. By injecting Synvisc in a knee, some people consider this a so-called joint lubrication. This is why you may hear of Syvisc as a 'motor oil' for the knee joint
Numerous studies have been performed in the past decade to assess the effectiveness of Synvisc as a treatment for osteoarthritis. However, no clear understanding of how well Synvisc injections perform has emerged. Early studies of Synvisc were performed on too few patients and the follow-up period was limited to a short time. Some studies showed a benefit of Synvisc injections, primarily in reduction of pain.