Tearing of the anteroinferior glenoid labrum (Bankart lesion) and of the posteroinferior glenoid labrum (reverse Bankart lesion) are well-documented, common injuries following traumatic shoulder subluxation or dislocation. The labral injury, as well as the loss of tension of the attached capsuloligamentous structures, is known to lead to recurrent instability.

Injuries to the capsuloligamentous attachments to the humerus are much less common but have recently gained attentionduetoadvancementsinarthroscopicexperienceand imaging techniques. In 1942, Nicola first described an acute shoulder dislocation with avulsion of the anterior band of the inferior glenohumeral ligament (IGHL). In 1988, Bach described a humeral avulsion of the lateral capsule as a cause for recurrent shoulder dislocation. The term “humeral avulsion of glenohumeral ligaments (HAGL),” which is now commonly used for this pathology, was introduced by Wolf in 1995. Although the typical anterior HAGL lesion is more common, posterior injuries do occur. These are referred to as reverse or posterior HAGL (PHAGL) lesions and involve an avulsion of the posterior band of the IGHL from the humeral neck. While rare, these lesions have been shown to contribute to recurrent instability.

Full Article: HAGL and Reverse HAGL Lesions