The role of the meniscus in an instability model for osteoarthritis in the rabbit knee.

After division of the cruciate ligaments and one meniscus in the knee joint of the rabbit, degenerative changes were observed in both the articular cartilage and bone. This was more apparent on the tibial plateau in which the meniscus had been removed, progressive changes occurring from 3 to 16 weeks after trauma. A parallel in vitro experiment, involving measuring the lateral displacement of the tibia in the rabbit knee during medial-lateral leading, was performed before and after transverse division of the meniscus alone. The resulting displacements during medial-lateral shear loading approximately doubled after meniscectomy in the mechanical tests, the apparent clinical stability still being provided after meniscus division by the collateral ligaments, joint capsule, cruciates and bone geometry.