Osteoarthritis following ACL reconstruction

描述（由申请人提供）：本研究的目的是通过实验模型评估前交叉韧带（ACL）重建后骨关节炎（OA）的进展。前交叉韧带断裂是导致创伤后骨关节炎的常见损伤。在许多患者中，手术重建前交叉韧带是必要的，以恢复关节功能，并阻止前交叉韧带损伤后骨性关节炎的进展。由于前交叉韧带是胫骨相对于股骨前移的主要约束，理论上，正确植入前交叉韧带应该恢复正常的运动学，从而恢复胫骨股骨接触应力的分布和大小，防止骨关节炎的进展。此外，术中参数，如固定时施加于移植物的初始张力（“初始移植物张力”）也可能影响手术后关节软骨的完整性，因为它是直接影响膝关节运动学和胫股接触应力的参数。然而，有临床证据表明，ACL重建可能不能阻止骨关节炎的进展。ACL重建的益处和初始移植物张力对OA进展的影响尚未确定。本研究将比较5个试验组：1)acl完整的山羊（对照组）；2)在低初始张力下移植重建前交叉韧带的山羊；3)在高初始张力下移植重建前交叉韧带的山羊；4) ACL部分未治疗的山羊；5) acl完整的山羊在一条腿上进行假手术。初步干预后，动物将经历26周的愈合期，之后将评估关节软骨的力学特性（和组织学）和膝关节运动学（a - p松弛）。本研究的主要目的是比较从胫股关节获得的关节软骨的聚集模量（一种材料性质），以建立前交叉韧带重建与骨关节炎26周后愈合进展之间的关系，并确定初始移植物张力如何影响这种关系。第二个目的是测量前交叉韧带手术后A-P膝关节松弛的时间变化，以建立前交叉韧带重建膝关节中关节软骨材料特性与膝关节运动学之间的关系。本工作完成后，该模型可用于研究ACL重建手术的其他参数（如半月板和软骨下骨状态、移植物位置和术后康复）的影响，并评估OA进展的潜在机制。

DESCRIPTION (provided by applicant): The objective of this investigation is to evaluate the progression of osteoarthritis (OA) following anterior cruciate ligament (ACL) reconstruction using an experimental model. Rupture of the ACL is a common debilitating injury that leads to post-traumatic OA. Surgical reconstruction of the ACL is necessary in many patients to restore joint function, and to stop the progression of OA that follows an ACL injury. Since the ACL is the primary restraint of anterior translation of the tibia relative to the femur, a properly implanted ACL graft should theoretically restore normal kinematics, and hence the distribution and magnitude of the tibiofemoral contact stresses, preventing the progression of OA. Furthermore, intra-operative parameters, such as the initial tension applied to the graft at the time of fixation ("initial graft tension") may also affect the integrity of articular cartilage following surgery since it is a parameter that directly affects knee kinematics and the tibiofemoral contact stress. However, there is clinical evidence to suggest that ACL reconstruction may not stop OA progression. The benefits of ACL reconstruction and the effect of initial graft tension on OA progression have not been established. Five experimental groups will be compared in this study: 1) Goats with intact ACLs (control group); 2) Goats with a reconstructed ACL implanted under a low initial graft tension; 3) Goats with a reconstructed ACL implanted under a high initial graft tension; 4) Goats with a section ACL that is left untreated; and 5) Goats with intact-ACLs who undergo a sham surgical procedure in one leg. After the initial intervention, the animals will undergo a 26-week healing period, after which the mechanical properties (and histology) of the articular cartilage, and knee kinematics (A-P laxity) will be evaluated. The primary aim of the study is to compare the aggregate moduli (a material property) of articular cartilage obtained from the tibiofemoral joints to establish the relationship between ACL reconstruction and the progression of OA following 26 weeks of graft healing, and to determine how initial graft tension affects this relationship. The secondary aim is to measure temporal changes in A-P knee laxity following ACL surgery to establish the relationship between the material properties of the articular cartilage and knee kinematics in the ACL reconstructed knee. After completion of this work, the model could be used to investigate the effects of other parameters of ACL reconstruction surgery (such as the meniscal and subchondral bone status, graft position, and post-operative rehabilitation), and to evaluate potential mechanisms of OA progression.