Tribological effectiveness of viscosupplements for osteoarthritis in knee joint

Abstract

Most common treatments for knee pain due to osteoarthritis are viscosupplementation and total knee replacement. Injecting hyaluronic acid in the knee can increase the viscosity of the synovial fluid (SF) considerably. Thereby, the lubrication properties of synovial fluid can improve and reduce the wear in cartilage. But certain studies reject the role of hyaluronic acid (HA) in alleviating knee pain. This experiment revealed the effectiveness of viscosupplementation. Wear test is carried out in a pin on disc apparatus, and the wear rate is calculated. Viscosupplement (VS) is added at different proportions in inflammated synovial fluid collected from osteoarthritis patients. Bovine femur plugs are used for wear test in 1/4th, 1/2nd, 3/4th concentrations of viscosupplement and in inflammated SF. Test is also carried out in pure HA. Tribological properties are tested in pin on disc wear testing machine. The rheological properties are also examined in these concentrations. The result shows that viscosity can be increased by adding viscosupplement. Shear stress is also increasing with the addition of viscosupplementation. VS can reduce the wear and the effect of viscosupplementation can be increased by aspirating the inflammated synovial fluid completely from the patient and injecting the viscosupplement in the knee.