Prosthetic knee menisci to be implanted in place of deteriorated native menisci to prevent damage to the articular cartilage of the femoral and tibial condyles and, thereby, to arrest the progressive development of osteoarthritis； said prosthetic menisci being made as a hollow form and inflated after implantation by injection of a settable polymer to shape them into congruence with the femoral and tibial condyles； being sized for the femoral and tibial condylar surfaces； having internal reinforcement for strength and durability； being made from materials having elastomeric characteristics similar to those of native menisci； having bearing surfaces treated chemically and/or physically to improve the efficiency of lubrication by synovial fluid and to enhance the wear characteristics of the bearing surfaces； and being restricted in translation within the interarticular space by anchorage of their anterior and posterior horns and by the provision of secondary locating elements.
