Humeral and glenoid detachment of the anterior inferior glenohumeral ligament: a cause of anterior shoulder instability.

Recurrent anterior unidirectional shoulder instability is most commonly associated with an avulsion of the glenoid attachment of the labroligamentous complex (Bankart lesion). However, additional capsular injury is often considered necessary to allow anterior dislocation. Five patients undergoing surgical stabilization for recurrent anterior instability were noted to have not only a classic Bankart lesion but also a complete disruption of the lateral capsule from the humeral neck. Repair of this "floating" anterior inferior glenohumeral ligament was accomplished by reattachment of the medial and lateral capsular disruptions and has led to excellent postoperative function in these patients. None of the patients has had instability after an average follow-up of 26 months. Identification and repair of this unusual anatomic lesion is important and if missed may have a significant negative effect on postoperative stability.