Biomechanics of Reverse Total Shoulder Arthroplasty

 描述(申请人提供)：反向全肩关节置换术(RTSA)是一种创新的手术方法，旨在恢复严重衰弱的肩部患者的功能。在美国使用10年来，在植入物设计和外科技术方面取得了重大进步，这一进步至今仍在继续。撇开进展不谈，患者的预后仍然存在很大的差异，这源于他们的病理、植入物的选择/放置，以及患者生理对非解剖关节设计的补偿程度。为了增加功能活动范围(ROM)并减少肩胛骨切迹等并发症，我们必须研究其可变性的来源，并建立一个基准来衡量未来的改善。此外，我们还必须为临床医生提供前瞻性的工具，通过改进的手术技术和植入物的选择来改善RTSA的结果。为此，我们建议：1)对RTSA肩部运动学随恢复时间的变化进行第一次纵向分析，2)在肩部模拟器中集成第一个准确的动态3D肩胸/肩关节运动模型，3)量化肱骨延长对外旋转活动度的影响，4)验证预测RTSA患者术后活动度的前瞻性临床算法。该提案中概述的独特技术提供了一个强大的工具包来评估手术干预对肩部的影响。在目标1中，这项研究将区分高活动度和低活动度患者的特征肩部运动学和植入物配置。这些数据还将使我们深入了解肩胛骨切迹的发生，因为它与RTSA术后肩关节-肱骨运动学的变化有关。在目标2中，模块化的RTSA和动态肩胛骨肩关节模拟器将允许使用运动学上准确的肩部实验室模型来研究肩关节延长、关节旋转中心和外旋转ROM之间的关系。这些数据将被用来创建一个临床算法来预测术后的ROM，该算法将通过从目标1预测患者术后ROM的程度来验证。这些发现一起将使未来的RTSA患者受益，因为减少变异性和增加可实现的ROM的目标实现了。临床ROM值算法将为临床医生提供一个新的工具，以前瞻性地评估RTSA植入物组件的选择和放置对术后ROM值的影响。运动学数据可用于开发有针对性的康复方案，以稳定肩胛骨并增加RTSA患者的活动度，或提高肌肉骨骼模型的准确性，该模型检查正常、病理和修复/替换肩部的运动和肌力。高精度的骨/植入物运动轮廓还可用于研究植入物撞击/撬动和关节不稳定等RTSA现象，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，使用肩膀的正常、病理和修复依赖的运动作为比较的基线。

 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.