[Failures of knee joint prostheses. An analysis of knee prostheses and component revisions, 1980-1987].

Total knee arthroplasty has become more common in the last 20 years as a result of the continuous improvement in prosthetic design and operative techniques. Therefore, there have also been more failures. To show the reasons for these failures and the difficulties and results of revision surgery we studied the 48 uni- or tricompartmental revisions of total knee arthroplasties we performed in our institute between 1980 and 1987. Twelve to 94 months (mean 40.4) after revision we found 66% good or very good results. The main reason for failure was a poor surgical technique, which we found in 69% in unicompartmental, and in 28% in tricompartmental prostheses. Revision surgery needs a high level of practical knowledge and flexibility. The main problems consist of correction of the alignment and the filling of bone defects. Thus, we reconstructed ten large defects at the tibial plateau, which resulted in one very good, seven good and two moderate results.