Patent ID: 9554911
Date: 2017-01-31
CPC Classifications: A61F

Claim:
1. An artificial knee joint comprising a femoral component and a tibial component cooperating with each other and configured for application to a femur and the tibia, respectively, wherein: the femoral component comprises an intercondylar groove, and a cam is disposed at the rear of the intercondylar groove; the tibial component comprises a medial condyle supporting surface, a lateral condyle supporting surface, and an upright post disposed between the medial condyle supporting surface and the lateral condyle supporting surface and cooperating with the intercondylar groove, the upright post comprises an anterior surface, a posterior surface, a first arc surface formed on a posterior-lateral surface of the upright post, and a second arc surface formed on a posterior-medial surface of the upright post, the second arc surface disposed adjacent a medial side of the first arc surface, the cam comprises a third arc surface formed on an anterior-lateral surface of the cam and a fourth arc surface formed on an anterior-medial surface of the cam, the third arc surface and the fourth arc surface cooperating with the first arc surface and the second arc surface, respectively; the first arc surface is configured to cooperate with the third arc surface to guide an external rotation of the femur relative to the tibia to simulate the external rotation of the femur relative to the tibia when the natural knee is flexed and extended; and the second arc surface is configured to cooperate with the fourth arc surface to limit the external rotation of the femur relative to the tibia, wherein the upright post is in the shape of a thumb with radian on the whole in side view, wherein the upright post is asymmetrically disposed on the tibial component and is disposed on a posterior-lateral portion of the tibial component, biased towards the lateral condyle supporting surface, wherein the first arc surface, the second arc surface, the third arc surface and the fourth arc surface are all circular or elliptical surfaces, wherein in a cross section view of the tibial component, the curvature of the first arc surface is the same as that of the third arc surface; the curvature of the second arc surface is the same as that of the fourth arc surface; and the curvature of the second arc surface and the fourth arc surface is smaller than that of the first arc surface and the third arc surface, and wherein in a cross section view of the tibial component, an included angle between a straight line, which connects a center of the first arc surface and a juncture of the first and second arc surfaces, and a straight line extending along a posterior-anterior axis of the tibial component, is 5 to 20 degrees.