Effect of Cortical Bone Thickness on the Magnitude and Classification of Hill Sachs Lesions Verses Glenoid Lesions

The shoulder is the most dislocated major joint in the body; approximately 2% of the population will dislocate their glenohumeral joint between the ages of 18 and 70 [1]. Hill-Sachs lesions, compression fractures resulting from the impaction of the posteroloateral humeral head against the solid anterior rim of the glenoid, occur in roughly 30–40% of all anterior dislocations. Humeral head defects have been linked to postoperative recurrent dislocations and overall instability of the shoulder following stabilization procedures for the capsule [2]. However, the forces and deformations required to create these lesions during shoulder dislocation should be identified to properly develop injury models and new repair techniques. Therefore, the objective of this study was to determine the forces required to create bony lesions on the humeral head and quantify the size of the resulting lesions. In order to achieve this objective, a repeatable testing protocol was developed to consistently produce Hill Sachs lesions.