ARTIFICIAL KNEE JOINT HAVING IMPROVED POST AND CAM STRUCTURE

摘要

This invention relates to an artificial knee joint of a PS type having an improved post and cam structure which can replace a natural knee joint. This artificial knee joint, which excludes the posterior cruciate ligament, includes: a femur joint member which is joined to an end portion of a tiber near a femur; a tibia joint member which is joined to an end portion of the femur near the tibia; and a bearing member which is placed between the femur and tibia joint members, wherein the femur joint member comprises the cam and the bearing member comprises the post. In the artificial knee joint, the post of the bearing member and the cam structure of the femur joint member are improved. Therefore, when the femur joint member is slightly rotated from an upper plane to a lower plane at the bearing member, the movement is performed so smoothly that the injury of the post can be minimized. Particularly, when the femur joint member is bent and inserted to a knee through the front depression portion of the post, a more natural rolling movement is enabled. A natural rolling movement is also possible when the femur joint member is completely bent by prevention of collision with the patella. Furthermore, in this artificial knee joint invention which has an improved post and cam structure, when the knee is bent, the displacement of the knee joint can be prevented through the increase of jump distance by placing the front part of the cam of the femur joint member higher than the rest of the cam. Consquently the knee can be bent more completely. For this purpose, the invention provides a PS type artificial knee joint, which excludes the posterior cruciate ligament, includes: a femur joint member which is jointed to an end portion of a tiber near a femur; a tibia joint member which is joined to an end portion of the femur near the tibia; and the bearing member which is placed between the femur and tibia joint members. The bearing member comprises the post formed with a posterior flection and the femur joint member includes the cam where a post contact flection is formed with curvature corresponding to the posterior flection, so that the femur joint member can be rotated on the plane through the contact with the post.