Abstract:
"Biomechanics of the Inferior Glenohumeral Ligament of the Shoulder During the Simple Translation Test"
This research aims to analyze the function of the inferior glenohumeral ligament (IGHL), a key soft tissue restraint of the glenohumeral joint, during a clinical diagnostic procedure known as the "simple translation test" using a subject-specific finite element (FE) model. The glenohumeral joint is one of the most complex and frequently injured joints in the human body, with a broad range of motion that also makes it highly unstable. The study used a subject-specific CT dataset to construct a finite element model of the humerus, scapula, humeral head cartilage, and IGHL. Experimentally measured 6-DOF kinematics were applied to this model to simulate the clinical test for anterior instability. The results demonstrated that first principal strains in the IGHL were highly inhomogeneous at maximum anterior translation, with strains ranging from 0-19% in the anterior band (AB-IGHL), 0-31% in the axillary pouch, and 1-38% in the posterior band (PB-IGHL). The highest strains were observed at the insertion sites during maximum external rotation, suggesting a transfer of load from the scapular insertion to the humeral insertion site as external rotation increased. A sensitivity study also revealed that changes in the material properties of the cartilage and IGHL significantly affected the strain distribution. These findings highlight the value of using computational analyses like the finite element method to better understand how stress and strain fields in the IGHL correlate with joint position. The research provides a foundation for enhancing the understanding of the IGHL's role in anterior stability, which could ultimately lead to improved rehabilitation protocols and more effective surgical procedures.
