抄録
The anterior cruciate ligament (ACL) is the most important ligament for anterior stability of the knee joint. The ACL is often ruptured by trauma, but is also injured in rheumatoid arthritis (RA) and osteoarthritis (OA) . We studied macroscopic findings of the ACL in RA (131 knees) and OA (41 knees) in the cases which received total knee replacement (TKR) from 1985. The injured ACL was classified into three types: N type (almost normal), E type (elongated ACL) and L type (torn ACL) . The incidence of the types was 29.8% (N type), 25.2 % (E type) and 45.0 % (L type) in RA, and in OA, 31.7 % (N type), 24.4 (E type) and 43.9% (L type) . There were no differences between RA and OA in this.
Anterior stability was examined by stress radiography with a Telos instrument before TKR, and the related macroscopic findings of the ACL were discussed in relation to anterior stability. The E type was found to be the most unstable of the three types in both RA and OA. This can be caused by other factors such as destruction of bone and cartilage and other soft tissue injury.
