COMPARISONS OF THE JOINT RESPONSES TO SURGICAL TRANSECTION AND TRAUMATIC RUPTURE OF THE ACL IN A RABBIT MODEL

摘要

Long-term participation in vigorous physical activity increases the risk of acute and chronic injuries to the knee. Two specific types of injury strongly associated with subsequent knee osteoarthritis (OA) are cruciate ligament damage and meniscal tears. Many clinical studies have discussed the high frequency of noncontact ACL injuries, for example, from jump landings. Axial compressive loading of the knee during landing from a jump can generate approximately 6-8 times bodyweight. With the tibial plateau having an inherent posterior slope of 10-15°, these loads can produce an anterior shift of the tibia during jump landings that result in isolated rupture of the anterior cruciate ligament (ACL) in the laboratory. These studies have shown acute damages in the articular cartilage and underlying subchondral and trabecular bone in the human cadaver joint. Clinically, in over 80% of ACL injury cases, characteristic osteochondral lesions occur in the posterolateral aspect of the tibia and/or anterolateral aspect of the lateral femoral condyle, potentially due to these levels of joint compressive loads. In order to study the result of ACL rupture in the chronic setting, surgical transection models of the ACL and/or meniscus have been developed over the years. However, these models do not replicate the acute and chronic effects of traumatic injury seen clinically to articular cartilage and subchondral bone. More recently, our laboratory has developed a traumatic model of ACL and meniscal injury that includes these elements. The objective of the current study was to compare the chronic responses of the knee joint to surgical transection and traumatic rupture of the ACL using the rabbit model. The hypothesis of the study was that the traumatic model would result in relatively more cartilage degeneration and alterations in subchondral bone underlying the tibial plateau and femoral chondyles of the impacted knee.