[Revision of tumour endoprostheses around the knee joint. Review and own results].

Revision of tumour endoprostheses around the knee joint is mainly caused by aseptic loosening and deep infection. Mechanical complications have been significantly reduced by improvements in prosthetic design. The rate of aseptic loosening after distal femur or proximal tibia replacement ranges from 10% to 45% depending on the time of follow-up and prosthetic design; the success rate after revision averages 75% at midterm follow-up. The rate of infection reported in the literature varies between 2.9% and 12%. One stage revision may be considered after acute infection without signs of loosening, after which a success rate of 77.8% can be expected. Two stage revision is mainly indicated in multi-resistant microorganisms as well as septic loosening, with a success rate of 75% after 5 years. Deep infection represents the most serious complication in long-term follow-up, often leading to amputation due to soft tissue problems after tumour resection. The authors were able to confirm the minimal decrease in MSTS score despite the large number of operations (15 patients: nine females, six males; median MSTS score 84%; mean 81%).