Abstract:
"Methodology and Sensitivity Studies for Finite Element Modeling of the Inferior Glenohumeral Ligament Complex"
This study presents a methodology for creating a three-dimensional finite element (FE) model of the inferior glenohumeral ligament (IGHL) complex to analyze its biomechanical function as a continuous structure. Researchers used a cadaveric shoulder to perform an anterior translation test at multiple external rotation angles, recording the joint kinematics. The geometry of the shoulder structures was captured using volumetric CT scans to build a subject-specific FE model where experimentally measured motions were applied. The analysis focused on first principal strains, insertion site forces, and contact forces within the IGHL complex. Results showed that strains were highly non-uniform across the ligament, with an in-plane shear-loading pattern that intensified with increased external rotation of the humerus. The highest insertion force, 36.7 N, occurred at the axillary pouch's insertion to the humerus, while the greatest contact force, 7.3 N, was found between the IGHL's anterior band and the humeral cartilage. Sensitivity studies revealed that strain predictions were highly dependent on the IGHL's bulk-to-shear modulus ratio and moderately sensitive to its elastic modulus. Conversely, predictions were insensitive to the material properties of the humeral cartilage, suggesting it can be modeled as a rigid body in future analyses to improve computational efficiency. This research provides a robust framework for future subject-specific modeling of IGHL mechanics.
