Tibial plate for a knee-joint endoprosthesis

Claim 1

A tibial plate for a knee-joint endoprosthesis affixed to an upper resected end of a tibia having a rim of hard corticalis surrounding a spongiosa mass, the endoprosthesis being slidingly engageable by a femoral part of the prosthesis, the tibial plate comprising: an upper sliding surface for the femoral part of the knee-joint endoprosthesis and a lower surface lying on the resected end of the tibia; and a reinforcement element in the plate between the upper and lower surfaces thereof for increasing bending resistance of the plate in response to loading by joint forces, the lower surface of the plate having an edge region in contact with the rim of corticalis of the tibia and bearing inward of the edge region upon the spongiosa of the resected tibial end, the reinforcement element increasing in thickness and stiffness inward from the edge region with the plate being sufficiently flexible that it can bend upon application of the joint forces and uniformly distribute to the spongiosa over the area thereof upon which the plate bears a uniform stress resulting from the joint forces and maintaining deformation of the spongiosa over the area substantially uniform with displacement of the forces over the upper sliding surface.