A Exploratory Research For Continuous Passive Motion To Slow Down The Cartilage Degeneration After Anterior Cruciate Ligament Injury

Introduction:this study aims to research the effects of continuous passive motion on articular cartilage after anterior cruciate ligament injury in rabbits, in order to explore the best movement manner to slow down the degeneration of cartilage and lay the foundation for anterior cruciate ligament reconstruction. Methods:Twenty four male New Zealand white rabbits (about three-months-old) were randomly selected one side of the knee joints to the anterior cruciate ligament transaction and divided into four groups averagely after operation:free feeding group, immobilization group, continuous passive movement group, and immobilization group after continuous passive movement. After Four weeks, medial tibial plateaus were researched to observe the general morphology, Mankin score, and measure the density of cartilage cells, hyaline cartilage and calcified cartilage thickness, and trabecular bone density of subchondral bone. Rusult:the cartilage surface of each group are different degrees of cartilage degeneration. Mankin scores of continuous passive motion group was significantly lower than free feeding group (p <0.05) and the immobilization group (p<0.01); the density of cartilage cells and hyaline cartilage thickness of continuous passive motion group was significantly higher than free feeding group and the immobilization group (p<0.01);calcified cartilage thickness and trabecular bone density of subchondral bone in immobilization group was significantly higher than the free feeding group and the continuous passive motion group, the difference was significant (p<0.01), there was no significant difference between continuous passive motion group and free feeding group in calcified cartilage thickness and trabecular bone density of subchondral bone. Conclusion:After anterior cruciate ligament injury, the cartilage degeneration is inevitable, and immobilization for the cartilage is fatal. Continuous passive motion is a good way to low down the degeneration of cartilage and lay the foundation for anterior cruciate ligament reconstruction.