Effects of Initial Graft Tension on ACL Reconstruction

描述(申请人提供)：前十字韧带(ACL)断裂是一种常见的损伤，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，尽管做了手术，骨性关节炎仍然存在。手术时对移植物施加的初始张力控制着膝关节的运动和关节接触应力的分布，这些因素被认为是诱发骨关节炎的因素。我们的主要目标是在一项前瞻性、随机、双盲的对照研究中评估移植物初始张力对前交叉韧带重建后关节软骨反应的影响。接受自体移植重建前交叉韧带的患者被随机分为两组：1)初始移植张力设定使重建膝关节的前后(A-P)松弛程度等于对侧正常膝关节(“低张力”治疗)；2)初始移植张力设定为使重建膝关节的A-P松弛比对侧膝关节减少2-mm(“高张力”治疗)。另外招募了一组没有膝关节损伤证据的受试者作为对照。在当前的供资周期中，正在评估短期成果(3年)。在这次竞争性续签中，随访期将延长到至少7年。长期的随访是必要的，以明确哪些患者将出现骨性关节炎。通过X线片缩小关节间隙是量化骨性关节炎进展的唯一有效测量方法，并将继续作为研究的主要结果测量方法。定量和半定量磁共振成像也将用于评估软骨体积丢失和相关组织的完整性。初始移植物张力的影响也将使用A-P松弛(移植物完整性和膝关节运动学的指标)、等速力量(动态功能的指标)以及以患者为中心的验证和临床结果评分的次要结果来评估。我们假设，经过7年的愈合，“高张力”治疗组的重建膝关节的胫股关节间隙宽度和软骨厚度将与对照组相当，而“低张力”治疗组的重建膝关节的胫股关节间隙宽度和软骨厚度将小于对照组(表示为骨关节炎)。我们还预计，那些术后松弛程度增加的患者将更容易发生骨关节炎。还将评估不同成果衡量标准之间的关系。公共卫生相关性：前交叉韧带损伤已经达到流行的程度，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生率，并将确定手术技术的改进是否可以减少软骨退化。它还将探索关节炎的潜在原因，并验证在疾病的早期阶段检测关节炎的方法。因此，这些数据可能会影响未来对前交叉韧带损伤患者的护理，并减少与这种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.