[Arthroscopic findings of cartilage changes in knees with rheumatoid arthritis]

We evaluated 28 cases (45 knee joints) with rheumatoid arthritis as our subjects using simple X-rays of the knee joints according to their Larsen grade and also measured the femoro-tibial angle (FTA). Moreover, using an arthroscope we observed 6 regions, namely, the medial femoral condyle, medial tibial plateau, medial meniscus, lateral femoral condyle, lateral tibial plateau, and lateral meniscus, and evaluated the degree of cartilage degeneration according to a 5-point grade classification of our own devising. We studied the relationship between the simple X-ray findings and the arthroscopic findings of cartilage degeneration and reached the following conclusions. Even when simple X-ray findings are slight as in Larsen grade I, various degrees of cartilage degeneration are observed and moreover, as the stage of the disease progresses, cartilage degeneration becomes more severe. The progression of cartilage degeneration up to Larsen grade III is not uniform but degenerative changes in the lateral meniscus progress. Also, a correlation was observed between the nature of the cartilage destruction and the FTA.