Knee joint mechanics assessments

膝关节前交叉韧带(ACL)完整性的丧失也会改变关节的稳定性和动力学，并导致更高的风险和骨关节炎(OA)的发生率。然而，关节结构内关节接触力学的直接非侵入性体内量化一直是有限的。因此，正常健康的关节力学特征以及那些导致病理情况的特征还没有得到很好的确立。总的研究目标是了解关节力学、关节健康状况、关节损伤和修复机制之间的关系，以及与韧带损伤和修复相关的退行性变化的发展。将检验三个主要假设：(H1)通过体内膝关节僵硬测量和前交叉韧带松弛预测检测到前交叉韧带完整性和关节组织状况的差异，(H2)软骨力-变形(FD)特征与蛋白多糖(PG)浓度相关联，(H3)异常的动态关节稳定性与体内关节僵硬、软骨fd特征和PG浓度的变化相关。在不同屈膝和负荷条件下，对健康、先天性关节松弛、前交叉韧带缺乏伴早期退行性改变和前交叉韧带缺乏伴严重骨性关节炎4组的膝关节松弛程度和软骨力-变形特征进行成像和量化。使用新的关节松弛装置、磁共振成像、图像配准技术和建模，将开发出关节和前交叉韧带松弛组织特征的标准范围。体内软骨变形特征将被评估，并与软骨成分(蛋白多糖浓度)相关联，使用创新的成像技术和加载设备。将使用3D运动分析评估每组的关节动态稳定性，并将其与组织特征相关联。这项研究为联合表征工具包奠定了基础，并提供了一项独特而新颖的进展，对临床治疗评估具有潜在影响。

The loss of integrity of the anterior cruciate ligament (ACL) in the knee can also alter joint stability and dynamics and lead to higher risk and incidence of osteoarthritis (OA). However, direct non-invasive in-vivo quantification of joint contact mechanics within the joint structures has been limited. Consequently, characteristics of normal healthy joint mechanics, and those leading to pathological conditions are not well established. The overall research goals are to understand relations amongst joint mechanics, joint health status, joint injury and repair mechanisms, and the development of degenerative changes associated with ligament injury and repair. Three main hypotheses will be tested: (H1) Differences in ACL integrity and joint tissue condition are detected with in-vivo knee joint stiffness measures and ACL laxity predictions, (H2) Cartilage force-deformation (FD) characteristics are correlated to proteoglycan (PG) concentrations using integrated MRI and joint loading techniques, and (H3) Abnormal dynamic joint stability is correlated with alterations in vivo joint stiffness, cartilage FD characteristics and PG concentrations. Knee joint laxity, and cartilage force-deformation characteristics will be imaged and quantified for 4 in-vivo groups: healthy, congenital joint laxity, ACL deficient with early degenerative changes and ACL deficient with severe OA, under various knee flexion and loading conditions. Using novel joint laxity device, MR imaging, image registration techniques, and modeling, normative ranges for joint and ACL laxity tissue characteristics will be developed. In-vivo cartilage deformation characteristics will be evaluated and correlated with cartilage composition (proteoglycan concentration) using innovative imaging techniques and loading devices. Joint dynamic stability will be assessed for each group using 3D motion analysis, and correlated to tissue characteristics. This research develops the foundations for a joint characterization toolkit, and provides a unique and novel advance with potential impact for clinical treatment evaluations.