Effects of Initial Graft Tension on ACL Reconstruction

描述（由申请方提供）：前交叉韧带（ACL）断裂是一种常见损伤，通常需要手术重建以恢复功能并防止创伤后骨关节炎（OA）的进展。然而，有证据表明，尽管手术，OA仍然存在。手术时施加于移植物的初始张力控制膝关节运动和关节接触应力的分布，这些因素被认为是诱发OA的因素。我们的主要目的是在一项前瞻性、随机、双盲对照研究中评价ACL重建后初始移植物张力对关节软骨反应的影响。自体移植物ACL重建的候选患者被随机分配到两个治疗组之一：1）初始移植物张力设置，使得重建膝关节的前后（A-P）松弛度等于对侧正常膝关节的前后（A-P）松弛度（“低张力”治疗），和2）初始移植物张力设定为相对于对侧膝关节的A-P松弛度减少2 mm（“高张力”治疗）。招募了另一组没有膝关节损伤证据的受试者作为对照组。在本供资周期，正在评估短期成果（<3年）。在本次竞争性更新中，随访将延长至至少7年。长期随访是必要的，以明确识别那些将出现骨关节炎的患者。通过放射学检查确定的关节间隙狭窄是量化OA进展的唯一有效指标，并将继续作为本研究的主要结局指标。定量和半定量MRI也将用于评估软骨体积损失和相关组织的完整性。初始移植物张力的影响还将使用A-P松弛度（移植物完整性和膝关节运动学的指标）、等速强度（动态功能的指标）以及经验证的以患者为导向的临床结局评分等次要结局指标进行评估。我们假设在7年的愈合后，“高张力”治疗组的重建膝关节中的胫股关节间隙宽度和软骨厚度将等于对照组的胫股关节间隙宽度和软骨厚度，而“低张力”治疗组的胫股关节间隙宽度和软骨厚度将小于对照组的胫股关节间隙宽度和软骨厚度（指示OA）。我们还预计，手术后松弛度增加的患者更容易患骨关节炎。还将评估不同结局指标之间的关系。公共卫生相关性：ACL损伤已达到流行病的比例，并将患者置于创伤后关节炎的高风险中。这项拟议的研究将确定膝关节韧带手术后关节炎的发病率，并将确定手术技术的修改是否可以减少软骨退化。它还将探索关节炎的潜在原因，并验证用于在疾病早期检测关节炎的方法。因此，这些数据可能会影响ACL损伤患者的未来护理，并减少与该损伤相关的创伤后关节炎的经济负担。

DESCRIPTION (provided by applicant): Disruption of the anterior cruciate ligament (ACL) is a common injury that usually requires surgical reconstruction to restore function and prevent the progression of post- traumatic osteoarthritis (OA). However, evidence suggests that OA persists despite surgery. The initial tension applied to the graft at the time of surgery controls knee motion and the distribution of joint contact stress, factors thought to induce OA. Our primary objective is to evaluate the effects of initial graft tension on the articular cartilage response following ACL reconstruction in a prospective, randomized, double-blinded controlled study. Patients who were candidates for ACL reconstruction with an autograft were randomized into one of two treatment groups: 1) initial graft tension set such that the anterior-posterior (A-P) laxity of the reconstructed knee is equal to that of the contralateral normal knee (the "low-tension" treatment), and 2) initial graft tension set to reduce A-P laxity by 2-mm relative to that of the contralateral knee (the "high-tension" treatment). An additional group of subjects without evidence of knee injury was recruited to serve as a control. In the current funding cycle, the short-term outcome (<3 years) is being assessed. In this competitive renewal, the follow-up will be extended to a minimum of 7-years. The long-term follow-up is necessary to clearly identify those patients who will present with osteoarthritis. Joint space narrowing via radiography is the only validated measure for quantifying OA progression, and will continue to serve as the primary outcome measure for the study. Quantitative and semi-quantitative MRIs will also be used to assess cartilage volume loss and the integrity of related tissues. The effects of initial graft tension will also be assessed using the secondary outcome measures of A-P laxity (an indicator of graft integrity and knee kinematics), isokinetic strength (an indicator of dynamic function), and validated patient-oriented and clinical outcome scores. We hypothesize that after 7-years of healing, the tibiofemoral joint space width and cartilage thickness in the reconstructed knees of the "high-tension" treatment group will be equal to those of the control group, while that of the the "low- tension" treatment group will be less than those of the control group (indicating OA). We also expect that those patients with increased laxity following surgery will be more prone to osteoarthritis. The relationships between the different outcome measures will also be assessed. PUBLIC HEALTH RELEVANCE: ACL injuries have reached epidemic proportions and place the patient at high risk for post-traumatic arthritis. The proposed study will establish the incidence of arthritis following knee ligament surgery, and will determine if a modification in the surgical technique can reduce cartilage degeneration. It will also explore potential causes of arthritis and validate methods used to detect arthritis in the early stages of the disease. Therefore these data could impact the future care of the ACL injured patient and reduce the economic burden of post- traumatic arthritis associated with this injury.