This three-part cadaveric study defines which structures prevent anterior glenohumeral dislocation at different arm positions. Using anatomical dissection (36 embalmed shoulders), fluoroscopic marker tracking, and sequential sectioning (10 unembalmed shoulders), the authors determined the position-specific contribution of the subscapularis, and the superior, middle, and inferior glenohumeral ligaments.
Before this paper, shoulder stabilization surgery focused on either the subscapularis (Magnuson procedure) or the anterior capsule — without recognizing that different structures dominate at different arm positions. The missing piece was understanding why the classic apprehension position (abduction + external rotation) is uniquely dangerous.
When your patient dislocates in the abducted, externally rotated position, the culprit is the inferior glenohumeral ligament. Not the subscapularis. Subscapularis-tightening procedures alone will overconstrain external rotation without addressing the actual anatomical deficit at 90° abduction.
For instability at low abduction angles, subscapularis imbrication with capsule repair is appropriate and spares external rotation. For instability at higher abduction angles, the repair must address the inferior capsuloligenous complex. Splitting the subscapularis in line with its fibers to access and plicate the underlying capsule is all that is needed.
This paper is why we target the inferior GHL in Bankart repair and capsular shift procedures, and why preserving the subscapularis as a functional unit (rather than transecting it) is the preferred surgical approach when the real pathology lies deeper.
This three-part cadaveric study defines which structures prevent anterior glenohumeral dislocation at different arm positions. Using anatomical dissection (36 embalmed shoulders), fluoroscopic marker tracking, and sequential sectioning (10 unembalmed shoulders), the authors determined the position-specific contribution of the subscapularis, and the superior, middle, and inferior glenohumeral ligaments.
Before this paper, shoulder stabilization surgery focused on either the subscapularis (Magnuson procedure) or the anterior capsule — without recognizing that different structures dominate at different arm positions. The missing piece was understanding why the classic apprehension position (abduction + external rotation) is uniquely dangerous.
When your patient dislocates in the abducted, externally rotated position, the culprit is the inferior glenohumeral ligament. Not the subscapularis. Subscapularis-tightening procedures alone will overconstrain external rotation without addressing the actual anatomical deficit at 90° abduction.
For instability at low abduction angles, subscapularis imbrication with capsule repair is appropriate and spares external rotation. For instability at higher abduction angles, the repair must address the inferior capsuloligenous complex. Splitting the subscapularis in line with its fibers to access and plicate the underlying capsule is all that is needed.
This paper is why we target the inferior GHL in Bankart repair and capsular shift procedures, and why preserving the subscapularis as a functional unit (rather than transecting it) is the preferred surgical approach when the real pathology lies deeper.