Synvisc® (hylan G-F 20) is a viscosupplement injection that supplements the fluid in your knee to help lubricate and cushion the joint. Synvisc is a sterile high molecular weight fluid, which contains Hylan A fluid, Hylan B gel and salt water designed to treat osteoarthritis pain in the knee, hip, ankle or shoulder. The treatment works by restoring the elasticity and viscosity within the joint allowing a more extensive movement of the joint. Synvisc® can be used as a temporary replacement and supplement for synovial fluid for patients with osteoarthritis, who have failed to respond to a more conservative therapy, such as non-drug treatment options.Osteoarthritis treatment that contains hylan, a natural found in the synovial fluid of the joints.