Age related biomechanical properties of the glenoid–anterior band of the inferior glenohumeral ligament–humerus complex

Objective. To quantify the biomechanical properties of the glenoid–anterior band of the inferior glenohumeral ligament–humerus complex for the two age groups. Design. In vitro human cadaver study evaluating the biomechanical properties of the glenoid–anterior band of the inferior glenohumeral ligament–humerus complex for a younger group (n=5, mean age 38.5, SD 0.5 years) and an older group (n=7, mean age 74.8, SD 5.3 years). Background. Glenohumeral instability is more of a problem in younger than in older individuals, primarily because recurrence is much more common at a young age. Methods. Tensile testing was performed on the glenoid–anterior band of the inferior glenohumeral ligament–humerus complex in the shoulder apprehension position using a custom jig, Instron machine and a video digitizing system. Results. In the younger individuals disruption of the complex most often occurred at the glenoid–labrum region of the glenoid insertion site. In the older individual, disruption most often occurred at the midsubstance region. The load and the stress at failure of the glenoid–anterior band of the inferior glenohumeral ligament–humerus complex showed that the older group was only 61% and 46% of the younger group, respectively. Conclusions. The structural properties of the glenoid–anterior band of the inferior glenohumeral ligament–humerus complex and the material characteristics of the anterior band of the inferior glenohumeral ligament for the younger group were significantly superior than the older group.