[Interaction between construction and fixation of knee endoprostheses (author's transl)].

The two completely different total knee-endoprostheses (hinge type and sled or runner type) have been compared concerning construction and ability for take up or transmission of forces and moments. The difference to the real knee joint are described. The reactions on fixing of endoprostheses in the bone caused by the construction are emphasized. By a systematic analysis of the so called sled-prostheses is to be shown to differantiate between real sled-prostheses with rotation and sliding mobility and pseudo-sled-prostheses (better rotation-segment-prostheses). They have only one possibility of rotation to realize the knee bending. The kind and number of existing "degrees of freedom" are used as a significant characteristic to differentiate the various endoprostheses principles and their variants. This study should mainly inspirate for a systematic comparison of efficiency of the different types of knee-endoprostheses. This should give the operating surgeon for a length of time an objective aid to decision.