MECHANICAL STRUCTURES RESISTING ANTERIOR INSTABILITY IN A COMPUTATIONAL GLENOHUMERAL JOINT MODEL

Abstract

MECHANICAL STRUCTURES RESISTING ANTERIOR INSTABILITY IN A COMPUTATIONAL GLENOHUMERAL JOINT MODEL By Kevin A. Elmore, B.S. A Thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in Biomedical Engineering at Virginia Commonwealth University. Virginia Commonwealth University, 2009 Major Director: Dr. Jennifer S. Wayne Departments of Biomedical Engineering and Orthopaedic Surgery The glenohumeral joint is the most dislocated joint in the body due to the lack of bony constraints and dependence on soft tissue, primarily muscles and ligaments, to stabilize the joint. The goal of this study was to develop a computational model of the glenohumeral joint whereby joint behavior was dictated by articular contact, ligamentous constraints, muscle loading, and external perturbations. Validation of this computational model was achieved by comparing predicted results from the model to the results of a cadaveric experiment in which the relative contribution of muscles and ligaments to anterior joint stability was examined. The results showed the subscapularis to be critical to stabilization in both neutral and external rotations, the biceps stabilized the joint in neutral but not external rotation, and the inferior glenohumeral ligament resisted anterior displacement only in external rotation. Knowledge gained from this model could assist in pre-operative planning or the design of orthopedic implants. Use of this model as a companion to cadaveric testing could save valuable time and resources.