[Special endoprostheses of the knee joint in bone tumors]

Since the introduction of more effective adjuvant therapies in the area of primary and secondary bone tumors, limb salvage procedures have become more and more important. At the Orthopedic Department of the Technical University, Munich, 52 special knee prostheses have been implanted in patients with malignant tumors of the distal femur and proximal tibia. On the basis of the ISOLS criteria, the functional results achieved were excellent in 14%, good in 47%, satisfactory in 35%, and poor in only 5% of patients after an average follow-up period of 43 months (range: 3-156 months). The perioperative complication rate was 27%, and late complications were material fatigue and wear. In the case of primary tumors, a customized prostheses, and in the case of secondary tumors a modular system is recommended. Individual treatment planning is essential.