Biomechanics of Reverse Total Shoulder Arthroplasty

 描述（由申请人提供）：反向全肩关节置换术（rTSA）是一种创新的外科手术，用于恢复严重肩关节衰弱患者的功能。在美国使用的10年中，植入物设计和手术技术取得了显著进步，并且这种演变今天仍在继续。除了进步之外，患者结局仍存在很大的差异，这是由于他们的病理学、植入物的选择/放置以及患者生理学对非解剖关节设计的补偿程度。为了增加功能活动度（ROM）并减少肩胛骨切迹等并发症，我们必须研究其变异性的起源，并创建一个基准来衡量未来的改善。此外，我们必须为临床医生提供前瞻性工具，通过改进手术技术和植入物选择来改善rTSA结局。为此，我们建议：1）对rTSA肩关节运动学的恢复时间依赖性变化进行首次纵向分析，2）在肩关节模拟器中整合动态3D肩胛胸/肱骨运动的第一个准确模型，3）量化肱骨延长对外旋ROM的影响，以及4）制定前瞻性临床算法以预测rTSA患者的术后ROM。本提案中概述的独特技术提供了一个强大的工具包，以评估手术干预对肩部的影响。在目标1中，研究将区分具有高和低ROM结局的患者的特征性肩关节运动学和植入物配置。这些数据也将有助于深入了解肩胛骨切迹的发生，因为它与rTSA后肩胛肱骨运动学的变化有关。在目标2中，模块化rTSA和动态肩胛肩模拟器将允许使用肩关节运动学精确的实验室模型来研究肱骨延长、关节旋转中心和外旋ROM之间的关系。这些数据将用于创建预测术后ROM的临床算法，该算法将通过预测目标1患者的术后ROM程度来验证。这些发现将使未来的rTSA患者受益，因为减少变异性和增加可实现的ROM的目标已经实现。临床ROM算法将为临床医生提供一种新的工具，用于前瞻性评估rTSA植入物组件选择和放置对术后ROM的影响。运动学数据可用于制定有针对性的康复方案，以稳定rTSA患者的肩胛骨并增加ROM，或提高检查正常、病理和修复/置换肩部运动和肌肉力量的肌肉骨骼模型的准确性。高精度骨/植入物运动轮廓也可用于研究rTSA现象，如植入物撞击/勒韦林和关节不稳定性，并精确量化肩部运动分析中常见的皮肤标记运动伪影。最后，动态肩胛骨模拟器将创建一个平台，不仅可以研究rTSA，还可以研究任何软组织修复或关节置换，使用肩关节的正常、病理和修复相关运动作为比较基线。

 DESCRIPTION (provided by applicant): Reverse total shoulder arthroplasty (rTSA) is an innovative surgical procedure to return function to patients with severely debilitated shoulders. In 10 years of use in the US there have been significant advancements in implant design and surgical technique, and this evolution continues today. Advancements aside, there is still wide variability in patient outcomes that arise from their pathology, selection/placement of the implant, and the degree to which patient physiology compensates for the non-anatomic joint design. To increase functional range of motion (ROM) and reduce complications like scapular notching we must study the origins of their variability and create a benchmark against which to gauge future improvements. Also, we must generate prospective tools for clinicians to improve rTSA outcomes through modified surgical technique and implant selection. To do this we propose to: 1) Perform the first longitudinal analysis of recovery time-dependent changes in rTSA shoulder kinematics, 2) Integrate the first accurate model of dynamic 3D scapulothoracic/ humeral motion in a shoulder simulator, 3) Quantify the effects of humeral lengthening on external rotation ROM, and 4) Validate a prospective clinical algorithm to predict post-operative ROM in rTSA patients. The unique techniques outlined in this proposal provide a powerful toolkit to assess the impact of surgical intervention on the shoulder. In Aim 1, the research will differentiate the characteristic shoulder kinematics and implant configurations of patients with high and low ROM outcomes. The data will also lend insight into the onset of scapular notching as it relates to changes in scapulohumeral kinematics after rTSA. In Aim 2, a modular rTSA and dynamic scapula shoulder simulator will allow a kinematically accurate laboratory model of the shoulder to be used to investigate the relationships between humeral lengthening, joint center of rotation, and external rotation ROM. These data will be used to create a clinical algorithm that predicts post-operative ROM, which will be validated by predicting the degree of post-operative ROM in patients from Aim 1. Together these findings will benefit future rTSA patients as the goal of reducing variability and increasing achievable ROM is realized. The clinical ROM algorithm will give clinicians a new tool to prospectively assess the impact of rTSA implant component selection and placement on post-operative ROM. Kinematic data can be used to develop targeted rehabilitation protocols that stabilize the scapula and increase ROM in rTSA patients, or improve the accuracy of musculoskeletal models that examine motion and muscle forces in normal, pathologic and repaired/replaced shoulders. High accuracy bone/implant motion profiles can also be used to study rTSA phenomena like implant impingement/levering and joint instability, and precisely quantify skin marker motion artefacts common in shoulder motion analysis. Finally, the dynamic scapula simulator will create a platform to study not only rTSA, but any soft tissue repair or joint replacement using the normal, pathology- and repair-dependent motion of the shoulder as a baseline for comparison.