ABSTRACT
Commercial applications included polyethylene-porous tantalum acetabular components for total hip joint replacement and repair of defects in areas of cancellous bone, such as the acetabulum, femoral condyles, and tibial metaphysis. As the degree of constraint increases with knee replacements, the need to use of femoral and tibial intramedullary extensions of the prosthesis is greater, since the loads normally shared with the ligaments are then transferred to the prosthesis-bone interface. Total knee replacements can be implanted with cement or without cement, the latter relying on porous coating for xation. Alternative approaches to spinal fusion have been sought out and many in the past conceived the idea of disk replacement. Several designs have undergone clinical trials in human, mostly in Europe and the United States. An ideal design for total disk prosthesis is to provide a proper range of motion, proper patterns of motion, proper stiness in compression, bending and torsion, and stability.
