Wear of a Total Ankle Replacement

Osteoarthritis of the ankle is a disease that affects 2% of the population in the United States. The most common current treatment entails fusing the ankle. This leads to complications such as reduced range of motion, infection, non-union, and deterioration of adjacent joints. Total joint replacement is a successful treatment for osteoarthritis of the hip and the knee and recently, interest in using this procedure in the ankle has occurred. A review of the currently available total ankle replacements was completed finding a promising trend in the survivorship of the devices. It was also found that these devices still have complications of loosening and subsidence. A new total ankle replacement is described here. The kinematics and loading in the ankle is also discussed as it applies to the development of a wear test for this new device. Subsequently the wear rate, wear debris, and contact stress are compared to those reported in the literature. The wear test consisted of using both gravimetric and volumetric techniques. This new total ankle replacement was found to have a wear rate that is lower than existing ankle implants and similar to that found in other total joint replacements.