A Multi-Scale Modeling Construct of Knee Mechanics following ACL Reconstruction

描述(申请人提供)：前十字韧带(ACL)重建手术通常在改善关节稳定性方面是成功的，但患者因早期发病的骨关节炎(OA)而高度升高的RIK。目前尚不清楚这些患者发生骨性关节炎的原因，也不清楚如何制定最佳的治疗策略来降低骨性关节炎的风险。这是一个非常具有挑战性的问题，从经验上回答，因为前瞻性研究需要大量的受试者和多年的破译。目前生物力学中的计算模型不适合解决这个问题，因为它们将发生在宏观(全身)和微观(组织力学)尺度上的行为分离。因此，一种新的多尺度计算结构正在形成，以检验步态过程中肌肉骨骼动力学和软组织力学之间存在的内在耦合。这一结构被用来深入了解影响前交叉韧带重建后软骨接触应力的关键手术因素，这些因素被认为可以预测关节的骨关节炎变化。本研究的三个目的是：1)评估前交叉韧带移植物僵硬、预紧力和隧道结构对术中膝关节松弛程度的影响；2)研究手术因素和肌力对动态MRI测量的体内膝关节力学的影响；3)研究重建膝关节在人类运动过程中的多尺度生物力学行为。这些目的是用来检验这样的假设，即关节软骨接触应力的大小和位置随着主动肌肉负荷的变化而显著变化，并且对用于重建前交叉韧带的隧道的位置和方向也高度敏感。这些研究的结果对于提供最能降低韧带损伤和手术修复后骨性关节炎风险的临床方法是很重要的。

DESCRIPTION (provided by applicant): Anterior cruciate ligament (ACL) reconstructive surgeries are often successful at improving joint stability, but patients have a highly elevated rik for developing early onset osteoarthritis (OA). It is not well understood why OA develops in these patients, or how one can best plan a treatment strategy to mitigate the risk for OA. This is a very challenging question to answer empirically, since prospective studies require large subject numbers and many years to decipher. Current computational models in biomechanics are ill-suited to solve this problem because they decouple behavior that occurs at the macro (whole body) and micro (tissue mechanics) scales. Hence, a new multi-scale computational construct is being formulated to examine the inherent coupling that exists between musculoskeletal dynamics and soft tissue mechanics during gait. This construct is used to gain insights into the key surgical factors that can affect cartilage contact stresses after ACL reconstruction, which are believed to predicate osteoarthritic changes to the joint. The three aims of the study are to: 1) Assess effects of ACL graft stiffness, pre-tension and tunnel architecture on intra-operative assessments of knee laxity, 2) Investigate the coupled influence of surgical factors and muscle forces on in vivo knee mechanics as measured using dynamic MRI, 3) Investigate the multi-scale biomechanical behavior of reconstructed knees during human locomotion. These aims are used to test the hypothesis that articular cartilage contact stress magnitudes and location vary significantly with active muscle loading, and are also highly sensitive to the position and orientation of the tunnels used to reconstruct the ACL. The results of these studies are important for informing clinical approaches that can best mitigate the risk fo OA following ligament injury and surgical repair.