Kinematic effect of MGHL incorporation into Bankart repair.

Surgical treatment for traumatic shoulder instability has progressed in tandem with the evolution of the current understanding of the anatomy and biomechanics of the shoulder. Proponents of incorporating the middle glenohumeral ligament (MGHL) in Bankart repair believe this technique could increase repair strength. The purpose of this biomechanical study was to compare the range of motion and humeral head kinematic changes that result from including the MGHL in a Bankart repair in an effort to identify possible changes in shoulder biomechanics as a result of this addition in surgical repair.Six cadaveric shoulders were tested in 4 conditions: intact, Bankart lesion, repair excluding the MGHL, and repair including the MGHL. Each condition was tested for range of motion, glenohumeral translation, and humeral head apex position. Standard Bankart repair and repair with MGHL inclusion resulted in decreased range of motion, but no statistically significant difference was found between the 2 repair types (P=.846). Anterior translation was significantly reduced with both the Bankart repair (4.8 ± .9; P=.049) and included MGHL repair (4.6 ± 0.9; P=.029). No statistically significant difference was found between both repairs (P=.993). Although both repairs showed posterior displacement of the humeral head apex when in external rotation, this trend only reached statistical significance when compared with the Bankart lesion in 90° of external rotation (P=.0456); however, no significant difference was found between the 2 repairs (P=.999). Inclusion or exclusion of the MGHL in a Bankart repair does not significantly affect the range of motion, translation, or kinematics of the glenohumeral joint.