GLENOHUMERAL JOINT STABILITY: ROLE OF THE CAPSULE

描述(申请人提供)：肩部是身体最常脱位的关节。高达90%的年龄在25岁以下的人，他们的关节脱位和有单向的前路不稳，会复发，很难诊断，需要手术修复。手术治疗后，由于活动范围丧失、复发的不稳定、肩袖损伤或骨关节炎，20-25%的患者恢复正常功能仍然不够，结果不满意。因此，需要研究更好地了解肩部被动稳定器的功能，以设计更好的诊断方案和手术方法，并改善长期结果。总的假设是，当修复的肩周膜能够在术后即刻和长期恢复完整肩关节的功能时，肩部手术的结果将会得到改善。目前的肩关节稳定器模型将肩关节囊描述为单轴成分的集合(肩关节韧带)。因此，本项目的目标是使用一种新的关节前关节稳定性模型对关节囊的解剖学和生物力学进行全面的分析。这项拟议的工作将利用实验和计算相结合的方法来表征临床上相关关节位置的肩周膜的结构和功能。这项建议的三个具体目标是：1)量化局部多轴材料特性、微观结构形态和适当的本构模型，作为年龄和性别的函数；2)建立和验证临床相关关节位置的关节囊的特定对象的有限元模型；以及3)使用特定对象的有限元模型确定关节处于中外展、外展和收紧位置时的应力、应变分布和力。从这些创新和经过验证的模型中获得的定量数据是开发基于生物力学的新策略的第一个关键步骤，用于改进肩部脱位后的诊断程序和手术修复。这一方法也将作为分析整个肌肉骨骼系统中其他关节胶囊的最先进技术。

DESCRIPTION (provided by applicant): The shoulder is the most frequently dislocated joint of the body. Up to 90% of individuals less than 25 years of age that dislocate their glenohumeral joint and have unidirectional anterior instability suffer recurrence that is difficult to diagnose and necessitates surgical repair. Following surgical treatment, return to normal function remains inadequate with unsatisfactory results in 20-25% of patients due to loss of range of motion, recurrent instability, rotator cuff damage, or osteoarthritis. Therefore, research efforts to better understand the function of the passive stabilizers of the shoulder are needed to design better diagnostic protocols and surgical approaches as well as to improve the long-term outcome. The overall hypothesis is that the outcome of shoulder surgery will be improved when the repaired glenohumeral capsule can reproduce the function of the intact shoulder, both at the immediate post-operative periods and in the long-term. Current models of the shoulder stabilizers describe the glenohumeral capsule as a collection of uniaxial elements (glenohumeral ligaments). Therefore, the goal of this project is to perform a comprehensive analysis of the anatomy and biomechanics of the glenohumeral capsule using a novel model of anterior glenohumeral joint stability. The proposed work will utilize a combined experimental and computational approach to characterize the structure and function of the glenohumeral capsule in clinically relevant joint positions. The three Specific Aims of this proposal are: 1) quantify the local multi-axial material properties, microstructural morphology and appropriate constitutive model of the posterior, antero-superior and antero-inferior regions of the glenohumeral capsule as a function of age and gender; 2) develop and validate subject-specific finite element models of the glenohumeral capsule in clinically relevant joint positions; and 3) determine the stress and strain distribution as well as force in the glenohumeral capsule using subject-specific finite element models with the joint in mid-abduction, abduction and apprehension positions. The quantitative data obtained from these innovative and validated models is the first critical step towards the development of new biomechanically based strategies for improved diagnostic procedures and surgical repair following shoulder dislocation. This methodology will also serve as the state-of-the-art for analysis of other joint capsules throughout the musculoskeletal system.