Effect of experimental patellar luxation on the knee joint in the rat.

In 16 male Wistar albino rats the patella was fixed to the lateral aspect of the lateral condylus of the femur. Animals with luxated knee joint and controls were sacrificed 7-9 months after surgery. Operated knee joints were processed for histology and subjected to morphometric analysis in comparison to the controls.- It was found that (1) the artificial disturbance of the femoro-patellar junction resulted in a severe destruction of articular cartilages of the tibio-femoral and femoro-patellar junction; (2) the destructions progressed with time; (3) there was no substantial difference between the changes of the medial and lateral articular surfaces of the femur and tibia; (4) changes comprised focal cartilage necrosis, widening of cartilaginous area under the tide-mark, proliferation of subchondral bone and formation of osteophytes; (5) the fact that a change of the statics of femoro-patellar junction leads to panarthrosis, moreover that articular capsule, menisci, epi-, meta-, and diaphyseal bone areas are also involved, indicate the complexity of the question. The findings indicated that changes of the femoro-patellar junction play a role in the degenerative processes of the knee joint. It is concluded that early recognition and treatment of femoro-patellar alterations may help in the prevention of knee panarthrosis.