Quantitative MRI and gait analysis for ACL-injured and reconstructed knees

前十字韧带(ACL)损伤的受试者有很高的创伤后发展风险 尽管重建了前交叉韧带，但仍有骨关节炎(OA)。随着青少年前交叉韧带损伤数量的增加 人口，我们准备有一种年轻人的创伤后骨性关节炎和功能丧失的流行病 在接下来的十年里。生化和生物力学的早期检测是非常必要的。 前交叉韧带损伤和重建膝关节的异常。这种诊断早期退化的能力将使 早期干预，并将为新的外科或药理学提供指导和关键评估 治疗。磁共振(MR)T{1p}和T{2}定量已被用于检测早期软骨 退化。然而，目前还没有研究使用这些材料对前交叉韧带损伤的膝关节进行纵向研究。 先进的成像技术。运动学MRI允许确定3-D膝关节运动学， 包括软组织，在特定的载荷条件下。运动分析提供运动学评估 以及在行走、跑步和跳跃等生理条件下整个肢体的运动情况。在这 建议，我们将整合这三个量化指标，从组织组成到关节运动学和 对前交叉韧带损伤后的生物力学和生化异常进行纵向评价 并重建了膝盖。中心假说是前交叉韧带损伤的运动学和动力学异常。 重建的膝关节，通过运动学MRI和运动分析测量，将导致 MRI T{1P}和T{2}显示膝关节软骨退变加速。具体来说，我们的目标是1) 研究前交叉韧带损伤和重建膝关节软骨基质的纵向变化 MRI T{1p}和T{2}；2)研究前交叉韧带损伤后运动学和动力学的纵向变化。 使用运动学MRI和运动分析重建膝关节；以及3)研究相互关系 前交叉韧带损伤膝关节软骨退变与下肢运动学和动力学的关系。 急性前交叉韧带损伤患者的双侧膝关节将在基线(损伤后2-4周内)进行研究 和前交叉韧带重建前)、前交叉韧带重建后6个月、1年和3年。双膝双膝 年龄、性别和体重指数匹配的健康受试者将作为对照进行研究。凭借我们在以下领域的丰富经验 定量和运动学磁共振成像，以及人体运动和运动分析的可用性 功能测试核心，我们准备调查生化和 前交叉韧带损伤及重建膝关节的生物力学异常。更好地理解这一点 互动对于提高我们对创伤后骨性关节炎发展的机械知识至关重要。 严重受伤的关节。定量MRI和运动分析之间的相关性将有助于 了解导致退变的相互作用，并将这些技术应用于临床 最终改善患者管理和结果。

Subjects with anterior cruciate ligament (ACL) injuries have a high risk of developing post-traumatic osteoarthritis (OA) despite ACL reconstruction. With the increasing number of ACL injuries in the adolescent population, we are poised to have an epidemic of young adults with post-traumatic OA and loss of function within the next decade. There is a profound need for early detection of biochemical and biomechanical abnormalities in ACL-injured and reconstructed knees. This ability to diagnose early degeneration will enable early intervention, and will provide guidance and critical evaluation for new surgical or pharmacological therapies. Magnetic resonance (MR) T{1p} and T{2} quantification have been used to detect early cartilage degeneration. However, no studies have yet investigated ACL-injured knees longitudinally using these advanced imaging techniques. Kinematic MRI allows for the determination of 3-D knee joint kinematics, including soft tissues, under specific loading conditions. Motion analysis provides evaluation of kinematics and kinetics of the entire limb during physiologic conditions such as walking, running and jumping. In this proposal, we will integrate these three quantitative measures, from tissue composition to joint kinematics and entire limb function, to longitudinally evaluate the biomechanical and biochemical abnormalities in ACL-injured and reconstructed knees. The central hypothesis is that abnormal kinematics and kinetics of ACL-injured and reconstructed knees, as measured by kinematic MRI and motion analysis, will lead to accelerated cartilage degeneration of the knee joint, as indicated by MRI T{1p} and T{2}. Specifically we aim to 1) investigate longitudinal changes in cartilage matrix in ACL-injured and reconstructed knees as indicated by MRI T{1p} and T{2}; 2) To investigate longitudinal changes in kinematics and kinetics in ACL-injured and reconstructed knees using kinematic MRI and motion analysis; and 3) To investigate interrelationship between knee cartilage degeneration and lower extremity kinematics and kinetics in ACL-injured knees. Bilateral knees of patients with acute ACL-injures will be studied at baseline (within 2-4 weeks post injury and prior to ACL reconstruction), 6-month, 1-year and 3-year post ACL reconstruction. Bilateral knees of age, gender and BMI-matched healthy subjects will be studied as controls. With our extensive experience in quantitative and kinematic MRI, and the availability of motion analysis within the Human Performance and Functional Testing Core, we are equipped to investigate the interaction between biochemical and biomechanical abnormalities of ACL-injured and reconstructed knees. A better understanding of this interaction is critical to advance our mechanistic knowledge of post-traumatic OA development in acutely-injured joints. Correlations between quantitative MRI and motion analysis will facilitate an understanding of the interactions leading to degeneration, and translating these techniques into the clinic will ultimately improve patient management and outcome.