Effects of prosthesis design and placement on shoulder kinematics and strength after reverse shoulder arthroplasty

项目总结/摘要 反向肩关节成形术（RSA）是一种最常用于老年患者的外科手术， 由于不可修复的肩袖撕裂而无法抬起手臂的症状性肩关节炎患者。之前 手术后，患者可能会出现假性瘫痪，严重限制了他们独立工作的能力。 日常生活活动（ADL）。RSA恢复力量和运动范围（ROM），允许 三角肌来弥补肩袖的缺失然而，RSA后的临床结局通常是有利的， 并发症发生率仍然很高，功能结果（例如活动范围和力量）仍然不理想。 对尸体和计算机模拟的研究表明，功能结果可能会得到改善， 修改肩假体的设计和放置。然而，关于最好的方法仍然存在争议。 RSA术后最大化肩关节功能植入物几何形状和植入技术。这一争议 在很大程度上，由于缺乏定量的体内运动数据来指导这一争论，因此 对于RSA患者的活体肩部运动的定量存在着迫切的需求。我们研究的长期目标是 目的是改善RSA患者的临床和功能结局。该项目的目标是：1） 确定假体设计和放置对RSA后肩关节运动和力量的影响，以及2） 识别与改善的临床结果相关的运动和力量参数。参与者 将纳入30例术后1 - 5年的RSA患者。我们将使用双平面X线摄影对肩部进行成像 当参与者进行肩胛平面外展，内/外旋90 °外展时的运动， 触摸后脑勺，触摸下背部的中间。经过验证的跟踪系统， 在每个过程中，平移精度优于1 mm，旋转精度优于1 mm将决定肩关节运动。 运动将在屈曲/伸展期间使用等速测力法测量肩关节力量， 内旋/外旋和内收/内收。具体目的是确定假体的体内效果 对RSA后肩关节运动学和力量的放置和设计，并识别肩关节运动学 以及与改善的临床结果相关的强度参数。作为二次分析的一部分， 我们将确定关节盂球和肱骨臼之间接触区域的大小和位置， 表征假体的力学环境，以及肱骨臼和 肩胛骨，以识别可能导致肩胛骨切迹的体内运动。本研究的预期结果将 将假体放置和设计与术后体内肩关节功能和临床结局相关的新数据 RSA.这些知识可用于改善临床和功能结局，从而提高治疗质量。 RSA患者的生活这项研究将提供初步数据，为未来的研究提供信息，以调查影响 年龄、合并症和康复对RSA后肩关节运动学、力量和临床结局的影响。

Project Summary/Abstract Reverse shoulder arthroplasty (RSA) is a surgical procedure most often performed on elderly patients with symptomatic shoulder arthritis who are unable to elevate their arm due to an irreparable rotator cuff tear. Prior to surgery, patients may have pseudoparalysis that severely limits their ability to independently perform common activities of daily living (ADLs). RSA restores strength and range of motion (ROM) by allowing the deltoid to compensate for an absent rotator cuff. Clinical outcomes after RSA are generally favorable, however, complication rates remain high and functional outcomes (e.g. range of motion and strength) remain suboptimal. Research on cadavers and computer simulations suggest that functional outcomes may be improved by modifying the design and placement of the shoulder prosthesis. However, controversy still exists as to the best implant geometry and implantation technique for maximizing shoulder function after RSA. This controversy persists, in large part, due to the paucity of quantitative in vivo motion data to guide this debate. Therefore, a critical need exists for quantitative in vivo shoulder motion in RSA patients. The long-term goal of our research is to improve clinical and functional outcomes for patients who receive RSA. The goals of this project are: 1) to identify the effects of prosthesis design and placement on shoulder motion and strength after RSA, and 2) to identify the motion and strength parameters that are associated with improved clinical outcomes. Participants will be 30 RSA patients who are 1 to 5 years post-surgery. We will use biplane radiography to image shoulder motion while participants perform scapular plane abduction, internal/external rotation at 90 abduction, touching the back of the head, and touching the middle of the lower back. A validated tracking system that has a precision of better than 1 mm in translation and 1 in rotation will determine shoulder joint motion during each movement. Shoulder strength will be measured using isokinetic dynamometry during flexion/extension, internal/external rotation, and ab/adduction. The Specific Aims are to determine the in vivo effect of prosthesis placement and design on shoulder kinematics and strength after RSA, and to identify the shoulder kinematics and strength parameters that are associated with improved clinical outcomes. As part of a secondary analysis, we will determine the size and location of the contact region between the glenosphere and humerosocket to characterize the mechanical environment of the prosthesis, and the distance between the humerosocket and scapula to identify in vivo motions that may lead to scapular notching. The expected outcome of this study will be novel data relating prosthesis placement and design to in vivo shoulder function and clinical outcomes after RSA. This knowledge can be used to improve clinical and functional outcomes, leading to improved quality of life for RSA patients. This study will provide preliminary data to inform future studies to investigate the effects of age, comorbidities, and rehabilitation on shoulder kinematics, strength and clinical outcomes after RSA.