Femoral prosthesis with medialized patellar groove

摘要

A prosthetic femoral component (10) for an orthopaedic prosthesis has a canted patellar groove adapted for optimal patella/component interaction, with the component configured to have a medial or lateral cant depending upon the method of implantation. The femoral component defines a distal “component transverse plane,” which is a plane tangent to the distal-most points of the component condyles (12,14). In a “mechanical” implantation, the component transverse plane is substantially normal to the mechanical femoral axis of the femur after the component has been implanted. Where the femoral component is configured to be “mechanically oriented” in this manner, the component has a medially canted patellar groove. On the other hand, an “anatomic” implantation is one in which, after the component has been implanted, the component transverse plane is substantially parallel to an “anatomic” transverse plane. The anatomic transverse plane is perpendicular to the anatomic axis of the femur from a sagittal view, and is inclusive of a line connecting the distal-most points of the natural femoral condyles before resection. Where the femoral component is configured to be “anatomically oriented” in this way, the component has a non-canted or slightly laterally canted patellar groove.

主权项

1. A femoral component adapted to mount to a femur, the femur defining a mechanical axis and an anatomic axis, the component defining a component coordinate system having:
a component transverse plane; a coronal plane perpendicular to said component transverse plane; a sagittal plane perpendicular to said component transverse plane and including a component midline that is normal to said component transverse plane; the component having a bone-contacting surface and an opposed articulation surface, the component further having proximal, distal, anterior and posterior portions, the component comprising: a pair of condyles including a medial condyle and a lateral condyle, each of said condyles defining respective distal-most points and posterior-most points, said component transverse plane tangent to each of said distal-most points, said coronal plane tangent to at least one of said posterior-most points, and said sagittal plane disposed between said lateral condyle and said medial condyle; and a patellar groove proximate the anterior portion of the component, said component midline of said sagittal plane inclusive of a distal-most point of said patellar groove, said patellar groove extending from said distal-most point toward an anterior-most edge of said femoral component, said patellar groove defining a medially canted patellar axis when viewed from an anterior side of said component, said patellar axis medially diverging from said component midline as said patellar axis extends proximally to define a medially canted angle between said patellar axis and said component midline.