The Dynamic Glenoid Track: An Updated Model of Glenohumeral Cartilage Contact During In Vivo Movement

项目摘要/摘要 肩关节前不稳是经常参加体育活动的人的常见问题，具有严重的长期性 由于伤病复发率高以及由此导致的失业时间延长而产生的影响。伤病 导致前路不稳的原因通常包括对肱骨头(Hill-Sachs病变)和关节突的损害。 骨(Bony Bankart病变)。目前治疗前路不稳的现行手术指南 骨质损伤是基于生物力学研究，该研究测量了关节臼-肱骨接触区域(关节突 在静态模拟加载过程中的身体标本中)。基于身体的生物力学研究不能 复制活体负荷、运动学和肌肉活动，因此当前的指南缺乏准确性和 指导前肩不稳患者手术决策所需的概括性 亚临界(10%至20%)的肾盂骨质丢失。迫切需要提高我们对如何 解剖学和运动学影响活体运动过程中的关节接触，因此最佳的 外科治疗可以在这个具有挑战性的患者队列中确定。这项研究的目标是界定 动态关节突跟踪，并开发和验证患者特定的评估过程，基于 三种常见的肩关节前路手术后肩关节动态轨迹对肩功能的预测 不稳定。在这项机械辅助研究中，来自动态双平面摄影(DBR)的活体运动学将 结合MRI观察关节软骨的形态，测量关节接触区域的大小。 外展30°、60°、90°和120°外展时的无负荷外旋和外旋时(动态 关节轨迹)。将在健康对照中测量动态关节突轨迹，并与以前的 报告有静态的关节突迹。然后，来自健康肩膀的数据将被用来开发一个模型来预测 患者的软骨接触和不稳定是基于骨损伤的大小和位置。其有效性和有效性 该模型的稳健性将通过在手术前测试来自父母研究的患者来评估。最后， 患者特定模型预测手术后软骨接触区域的能力将使用 来自父母研究患者的手术前和手术后数据。其具体目的是：1)比较体内的 在健康的肩膀上的动态关节突轨迹与先前报道的静态关节突轨迹，2)发展和 验证患者特定评估方法在预测动态关节盘中关节-肩关节软骨接触中的作用 活体运动，以及3)确定特定于患者的模型在预测动态中的准确性 手术后肩关节软骨接触。实现这些目标将提供对解剖学的洞察 以及导致肩关节前稳定性丧失和恢复的运动学机制，并将澄清 并改进肩关节前路不稳和亚临界肩周炎患者的手术指南 损失。

Project Summary/Abstract Anterior shoulder instability is a common problem in physically active individuals and has serious long-term implications due to the high rate of injury recurrence and the resulting extended time out of work. The injury leading to anterior instability often includes damage to both the humeral head (Hill-Sachs lesion) and glenoid bone (bony Bankart lesion). The current surgical guidelines for treating anterior instability in the presence of bony lesions are based upon biomechanical studies that measured glenohumeral contact regions (the “glenoid track”) in cadaver specimens during static simulated loading. Cadaver-based biomechanical studies cannot replicate in vivo loads, kinematics, and muscle activity, and so the current guidelines lack the accuracy and generalizability needed to guide surgical decision-making in patients with anterior shoulder instability and subcritical (10% to 20%) glenoid bone loss. A critical need exists to improve our understanding of how anatomy and kinematics affect glenohumeral articular contact during in vivo movement so that the optimal surgical treatment can be identified in this challenging patient cohort. The objectives of this study are to define the dynamic glenoid track and to develop and validate a patient-specific evaluation process, based upon the dynamic glenoid track, to predict shoulder function after three common surgeries to treat anterior shoulder instability. In this mechanistic ancillary study, in vivo kinematics from dynamic biplane radiography (DBR) will be combined with cartilage morphology from MRI to measure glenohumeral contact regions during loaded and unloaded circumduction and during external rotation at 30°, 60°, 90° and 120° of abduction (the dynamic glenoid track). The dynamic glenoid track will be measured in healthy controls and compared to the previously reported static glenoid track. Data from healthy shoulders will then be used to develop a model to predict cartilage contact and instability in patients based upon bone lesion size and location. The validity and robustness of the model will be evaluated by testing patients from the parent study prior to surgery. Finally, the ability of the patient-specific models to predict cartilage contact regions after surgery will be evaluated using pre and post-surgery data from patients in the parent study. The Specific aims are: 1) to compare the in vivo dynamic glenoid track in healthy shoulders to the previously reported static glenoid track, 2) to develop and validate a patient-specific evaluation process for predicting glenohumeral cartilage contact during dynamic in vivo movement, and 3) to determine the accuracy of the patient-specific model in predicting dynamic glenohumeral cartilage contact after surgery. Achieving these objectives will provide insight into the anatomic and kinematic mechanisms that lead to the loss and restoration of anterior shoulder stability, and will clarify and improve the surgical guidelines for patients with anterior shoulder instability and subcritical glenoid bone loss.