Viscosupplementation aka "Rooster Comb, Gel Injections"
The knee is composed of three bones, the femur (thigh bone), the tibia (shin bone) and the patella (knee cap). The ends of these bones that move about each other have a layer of cartilage, which forms the surface of the joint. The lining of the joint produces synovial fluid which is composed of hyaluronic acid.
In arthritis the cartilage layer is progressively destroyed by mechanical factors and inflammation.