Abstract: A knee joint prosthesis comprises a femoral component for implantation on a prepared femoral condyle of a knee and a tibial component for implantation on a prepared corresponding tibial plateau of the knee. The femoral component has a femoral articular surface cooperable with a tibial articular surface of the tibial component to permit motion at the knee. The femoral articular surface has a medial-lateral radius of curvature, and the tibial articular surface has a medial-lateral radius of curvature 0.25 to 5.00 mm longer than the medial-lateral radius of curvature of the femoral articular surface. The tibial articular surface has a medial-lateral mid-point, and the femoral articular surface defines a tracking line for the femoral component which tracks in an anterior-posterior direction along the medial-lateral mid-point as the knee moves between extension and flexion. The tracking line tracks at a medial-lateral angle relative to the medial-lateral mid-point of the tibial articular surface.

Abstract: A method and instruments for replacing the articulating surfaces of a knee joint in which the diseased area is restricted to one of the medial and lateral compartments. A femoral intramedullary rod is placed down the center of the femur. A femoral cutting block is affixed at one side to the rod and at the other side to an outrigger attached to the femur by smooth pins. The cutting block is adjustable rotationally and in the anterior-posterior plane. The cutting block is provided with surgical saw guide slots for the posterior and distal articular surface cuts and the chamfer cuts, all of which are made with the cutting block in place. The cutting block is removed and a drill guide is used for drilling two holes in the distal articular cut surface for receipt of the mounting pegs of the femoral unicompartmental prosthetic implant.

Abstract: A method and instruments for replacing the articulating surfaces of a knee joint in which the diseased area is restricted to one of the medial and lateral compartments. A femoral intramedullary rod is placed down the center of the femur. A femoral cutting block is affixed at one side to the rod and at the other side to an outrigger attached to the femur by smooth pins. The cutting block is adjustable rotationally and in the anterior-posterior plane. The cutting block is provided with surgical saw guide slots for the posterior and distal articular surface cuts and the chamfer cuts, all of which are made with the cutting block in place. The cutting block is removed and a drill guide is used for drilling two holes in the distal articular cut surface for receipt of the mounting pegs of the femoral unicompartmental prosthetic implant.