Femoral component

Abstract

A femoral component () for mounting onto a femur and being adapted to articulate with a tibial bearing component in a knee prosthesis comprises proximal end portions () adapted to be oriented towards the femur when the femoral component () is mounted thereon, and distal end portions adapted to be oriented towards the tibial bearing component when the knee prosthesis is fully extended. The proximal end portions () comprise posterior proximal end portions which are located on an posterior side of the femoral component and an anterior proximal end portion () which is located on an anterior side of the femoral component (). The femoral component () further comprises a medial condyle () and a lateral condyle () which each extend from one of the posterior proximal end portions beyond the distal portions and towards the anterior proximal end portion () of the femoral component (). The medial and lateral condyles () form a condylar gap between each other, wherein the medial condyle () and the lateral condyle () are shaped to articulate with the tibial bearing component through a range of motion, in which a full extension of the knee prosthesis corresponds to zero degrees flexion of the knee prosthesis and positive flexion corresponds to greater than zero degrees flexion of the knee prosthesis. The femoral component () further comprises a sagittal plane extending in a proximal/distal direction and further extending through the condylar gap from the anterior side to the posterior side of the femoral component (). A patellar groove () extends from the condylar gap towards the anterior proximal end portion () of the femoral component () along a mathematical curve (). The mathematical curve (), when looking onto the anterior side of the femoral component, is canted towards a medial side () of the femoral component () relative to the sagittal plane when the patellar groove () extends proximally. The patellar groove () is formed by a concave groove section () on the anterior side of the femoral component (), the groove section () having a groove base (). The femoral component () further comprises a medial ridge section () and a lateral ridge section () which are disposed adjacent the groove section () and each have a convex shape. The medial ridge section () forms the medial condyle () and a medial extension () to the medial condyle () towards the anterior proximal end portion (). The lateral ridge section () forms the lateral condyle () and a lateral extension () to the lateral condyle () towards the anterior proximal end portion () of the femoral component (). The patellar groove () has opposing groove edges () located at a transition of the concave groove section () and the adjacent convex medial ridge section () as well as at a transition of the concave groove section () and the adjacent lateral ridge section (). A width (W) of the patellar groove is defined by a distance between the opposing groove edges () transverse to the mathematical curve (). A depth of the patellar groove () is defined between the groove base () and the medial ridge section () or the lateral ridge section () normal to the anterior side of the femoral component () and parallel to the sagittal plane. A normal distance from the sagittal plane to the mathematical curve (), as a function of the length of path of the mathematical curve () relative to its starting point at the condylar gap, changes in a non-linear way along the mathematical curve () from the condylar gap up to the anterior proximal end portion () of the femoral component (). The width (W) of the patellar groove () increases along the patellar groove () extending from the condylar gap up to the proximal end portion () of the femoral component (). The depth of the patellar groove () decreases along the patellar groove () extending from the condylar gap up to the proximal end portion () of the femoral component ().