TIBIAL KNEE PROSTHESIS

摘要

A knee prosthetic (3.11) including a tibial component (443) defining medial (479) and lateral (481) concavities shaped to receive medial (3.27) and lateral (3.29) femoral condyles of the femur. The concavities have first portions for contact with the condyles during normal knee flexion and second portions for contact with the condyles during deep, or high, knee flexion. The medial concavity can include a conforming boundary (510) that encompasses at least the first and second portions, wherein an area (490) inside the conforming boundary has a generally flat surface. The flat surface allows the medial femoral condyle to slide and rotate posteriorly during high knee flexion. The conforming boundary can have a generally triangular shape with an apex extending anteriorly and a relatively wider base extending posteriorly, wherein the apex includes the first portion and the base includes the second portion. The relatively wider base portion advantageously allows additional area for posteriorly directed articulating contact during high knee flexion.