Prosthesis for knee replacement

A prosthesis for knee replacement which comprises:

• (a) a femoral component having at least one substantially spheroidal condylar surface,
• (b) a tibial component including a tibial platform,
• (c) a plastic meniscal component located between the condylar bearing surface and the tibial component and being moveable on the platform said meniscal component being retained on a guide upstanding from the platform, said guide including a post and a cap which are fixed relative to the platform, the cap being received in a recess in the meniscal component and slidable in a track therein in the anterior-posterior direction, the cap being asymmetrical about at least one plane passing axially through the post and the recess having an opening which is so shaped that the meniscal component can be assembled onto the guide in a limited number of relative orientations of the meniscal component and the platform when the track does not lie in the anterior-posterior direction.

A prosthesis for knee replacement which comprises:

• (a) a femoral component having at least one substantially spheroidal condylar surface,
• (b) a tibial component including a tibial platform,
• (c) a plastic meniscal component located between the condylar bearing surface and the tibial component and being movable onto the platform, said meniscal component being retained on a guide upstanding from the platform, said guide including a post and a cap, the cap being received in a recess in the meniscal component and slidable in a track therein, the cap being asymmetrical about at least one plane passing axially through the post and the recess having an opening which is so shaped that the meniscal component can be assembled onto the guide in a limited number of relative orientations of the meniscal component and the platform, and the cap, when viewed in plan view, having one flat side which is parallel with an abutment projecting from the platform and positioned as an anterior stop for the meniscal component.