In vivo ACL Reconstruction Biomechanics

描述(申请人提供)：尽管有许多关于前交叉韧带重建的成功结果的报道，但超过40%的前交叉韧带重建患者存在异常松弛并接受翻修手术。此外，与更保守的治疗相比，前交叉韧带重建并不能降低骨关节炎的发生率。目前尚无定量数据显示在体六自由度(6-DOF)中，前交叉韧带(ACL)缺陷如何改变膝关节运动学，以及在体内生理负荷条件下，当代前交叉韧带重建如何恢复6自由度膝关节运动学改变。此外，还没有关于半月板联合损伤如何影响重建的前交叉韧带膝关节体内功能的数据报道。该项目的第一个目标是使用一种新的成像技术，在同一受试者中比较健康和急性前交叉韧带损伤的膝关节的体内生物力学。人体受试者的三维(3D)膝关节模型将从磁共振图像中创建。然后，这些模型将与一系列双透视图像集相匹配，以准确地再现膝关节在楼梯上升/下降、步态和负重屈伸等活动中的运动学。半月板联合损伤对前交叉韧带损伤膝关节的影响也将直接从三维膝关节模型中确定。本课题的第二个目的是对前交叉韧带重建术后患者进行长期随访研究。为了量化前交叉韧带重建和半月板复合损伤对前交叉韧带重建疗效的生物力学影响，来自第一个目标的同一患者将在前交叉韧带重建后6个月和36个月在三年内返回两次，进行额外的透视成像。将重建前交叉韧带的患者分为三组，无半月板损伤组、内侧半月板撕裂组和外侧半月板撕裂组。在第一个目标中进行相同的在体功能活动时，将再次测试前交叉韧带重建的膝关节，并测量6自由度膝关节运动学。定量分析半月板联合撕裂对前交叉韧带重建术后膝关节运动学的影响。这项拟议的研究是解决运动医学外科中最重要的临床问题之一的独特方法。我们简单而强大的分析技术将使我们深入了解前交叉韧带和半月板联合损伤对6自由度活体动态膝关节功能的影响。长期的随访数据将进一步阐明当代前交叉韧带重建在恢复正常膝关节功能方面的效果。这一知识将改善患者的护理，因为可以为新的前交叉韧带重建技术开发指南，以便更准确地再现正常的活体膝关节运动学。在恢复膝关节的正常生理功能从而防止长期关节退化的过程中，可以减少频繁去医院就诊、过度物理治疗和翻修手术的需要--所有这些都是当前做法固有的。与公共卫生相关。本研究将采用纵向实验设计，测量前交叉韧带(ACL)重建前后患者的六自由度膝关节运动学。并分析半月板复合损伤对前交叉韧带重建疗效的影响。本研究为开发新的前交叉韧带损伤手术治疗方法，恢复关节长期稳定性，预防前交叉韧带损伤术后关节退变提供了一个通用的、定量的生物力学指导。

DESCRIPTION (provided by applicant): Despite the numerous reports on the successful results of ACL reconstruction, upwards of 40% of ACL reconstruction patients have abnormal laxity and undergo revision surgery. Moreover, ACL reconstruction does not reduce the rate of osteoarthritis when compared to more conservative treatments. There is little quantitative data demonstrating how ACL deficiency alters in-vivo knee kinematics in six degrees-of-freedom (6DOF) and how the contemporary ACL reconstruction restores the altered knee kinematics in 6DOF under in-vivo physiological loading conditions. Further, no data has been reported on how the combined meniscal injury will affect the in-vivo function of the ACL reconstructed knees. The first aim of this project is to compare the in-vivo biomechanics of healthy and acute ACL-injured knees within the same subject using a novel imaging technique. Three-dimensional (3D) knee models of human subjects will be created from MR images. These models will then be matched to a series of dual fluoroscopic image sets to accurately reproduce the kinematics of the knee during activities such as stair ascent/descent, gait and weight-bearing flexion-extension. The effects of combined meniscal damage to the ACL-injured knee will be determined directly from the three-dimensional knee models as well. The second aim of this project is to investigate the patients after ACL reconstruction surgery in a long-term follow-up study. To quantify the biomechanical effects of ACL reconstruction and a combined meniscal injury towards the efficacy of ACL reconstruction, the same patients from the first aim will return two times over a three year period, at 6 and 36 months following ACL reconstruction, for additional fluoroscopic imaging. ACL-reconstructed patients will be divided into three groups, those with no meniscal injury, those with medial meniscal tears, and those with lateral meniscal tears. The ACL- reconstructed knees will be tested again during the same in-vivo functional activities performed in the first aim, and 6DOF knee kinematics will be measured. The effect of combined meniscal tear on knee joint kinematics after ACL reconstruction will be analyzed quantitatively. The proposed study is a unique approach to one of the most important clinical problems in Sports Medicine Surgery. Our easy and powerful analysis technique will provide a thorough understanding of the effects of the combined ACL and meniscal injury on the 6DOF in-vivo dynamic knee joint function. The long-term follow up data will further elucidate the efficacy of contemporary ACL reconstruction in restoring normal knee function. This knowledge will lead to an improved patient care, as a guideline can be developed for new ACL reconstruction techniques that more accurately reproduce the normal in-vivo knee kinematics. In restoring the normal physiological functions of the knee joint and thereby preventing long-term joint degeneration, the need for frequent hospital visits, excessive physical therapy, and revision surgery - all inherent to the current practice - could be reduced. PUBLIC HEALTH RELEVANCE. This investigation will measure the six degrees-of-freedom knee kinematics of patients before and after anterior cruciate ligament (ACL) reconstruction in a longitudinal experimental design. The effects of combined meniscal injury on the efficacy of ACL reconstruction will also be analyzed. The knowledge gained from this study will provide a general, quantitative biomechanical guideline for developing new surgical treatments of ACL injuries, thereby restoring long term joint stability and preventing joint degeneration after surgical reconstruction of the injured ACL.