[A contribution to the differential indication of endoprosthetic knee-joint substitution (author's transl)].

The article describes a few guiding points for indicating the need for a knee-joint endoprosthesis, basing on experience with 253 cases, followed up for 2--48 months. Following the application of prostheses according to Walldius-Debeyre and Guepar, several complications were seen which we tried to reduce by introducing four prostheses of different sizes, since the choice of the implantates could be adapted to the prevailing anatomical conditions. A hinged-joint prosthesis of the St. George type is indicated in cases of most severe axial deviation, severe flexion contraction, extensive loss of bone substance, and instability of the ligaments. Sheeban's prosthesis is indicated in severe damage involving both compartments, limited frontal axial deviation, and flexion contraction of not more than 25 degrees with intact lateral ligaments. In younger patients with rheumatoid arthritis we implant the Geomedic prosthesis. If only one knee-joint compartment is involved, and after the possibility of readjustment osteotomy has been excluded, we consider a sliding prosthesis to be the prosthesis of choice.