| 摘要 |
A prosthetic knee joint is provided having an extended position, an intermediate position, and a flexed position. The motion of the joint includes a minor segment from the extended position to the intermediate position, and a major segment from the intermediate position to the flexed position. The center of pressure between the femoral component and the tibial component moves rearward on the tibia during the minor segment. During the major segment, the joint flexes about an axis of rotation with the bearing surfaces on the femoral and tibial components being in congruent engagement. The distal surface of the femoral component includes two rails for engagement with a patellar prosthesis. The contour of the rails is either a straight line or a concave curve to provide line contact between the rails and the patellar prosthesis. In certain embodiments, the patellar prosthesis has a saddle-shaped surface so that the prosthesis and each of the rails can make contact over an area extending along the length of the rail.
|
