Knee joint endoprosthesis set and instruments

A knee joint endoprosthesis set comprising:

• modular knee joint endoprostheses in different sizes, each knee joint endoprosthesis comprising a tibial component for anchoring at a proximal end of the tibia, a femoral component for anchoring at a distal end of the femur, the femoral component comprising:
• a joint element for articulated cooperation with the tibial component and
• a shaft configured for anchoring in a medullary canal of the femur, the set comprising shafts in different sizes, each shaft having a shape that tapers from a distal end, facing toward the joint element, to a proximal free end of the shaft, and is designed with an oval cross-section at the distal end and with a round cross-section in both a horizontal transverse plane and a coronal plane, forming a hemispherical shape at the proximal free end of the shaft, wherein an ovality defined by the oval cross-section increases as the size of the shafts increases, wherein the different sizes are graded according to the ovality, wherein the shafts each have a lateral surface, wherein the lateral surface extends from the distal end to the proximal free end, and wherein the lateral surface is a transition surface between the oval cross-section at the distal end and the round cross-section at the proximal free end, and wherein the ovality is elliptical.