Abstract: A tibial plate for a knee-joint endoprosthesis has a reinforcement member capable of distributing the joint forces uniformly over the spongiosa so that the spongiosa will not atrophy and is subjected to flexture from the tibial plate which is also supported on a cut section of the corticalis surrounding the spongiosa.

Abstract: A femoral-neck implant has an elongated plate formed with a row of holes and adapted to fit against a femur below a trochanter, respective corticalis screws traversing the holes in the plate for securing same to the femur below the trochanter femur, a stiff upper concave portion unitary with and extending from the plate and adapted to fit against the trochanter, the portion having a plurality of holes. Respective tension-force-resisting spongiosa screws traverse the holes in the concave portion and reach from the portion into the head and through the neck of the femur. An internally threaded body is formed on the plate at a junction thereof and has a surface turned toward the femur which is flush with surfaces of the shaft and the portion turned toward the femur.