Humeral avulsion of glenohumeral ligament (HAGL lesion) is an important cause of anterior instability of the glenohumeral joint. It is often associated with other abnormalities and can be overlooked during either arthroscopy or an open stabilization procedure, correct preoperative diagnosis of the HAGL lesion on imaging is important and has a significant clinical implication.
The inferior glenohumeral ligament labral complex is the primary anterior stabilizer of the shoulder when the arm is at 90ï¿½ of abduction and external rotation. The inferior glenohumeral ligament labral complex consists of an anterior band, a posterior band, and an interposed axillary pouch.
Because an HAGL lesion can be overlooked during either arthroscopy or an open stabilization procedure, correct preoperative diagnosis of the HAGL lesion on imaging is important and has a significant clinical implication.
HAGL lesions can occur without (80%) or with (20%) bony avulsion from the medial cortex of the humeral neck. A combined Bankart lesion and lateral capsule avulsion has been termed the floating anterior inferior glenohumeral ligament. In the literature, the frequency of HAGL, floating anterior inferior glenohumeral ligament, and bony HAGL is 59%, 22%, and 20%, respectively. HAGL lesion has a male predominance of 97%. HAGL lesions occurred most often in rugby players (52%). However, the HAGL lesion is found in patients who participate in many other activities and sports. Recently having undergone capsular surgery likely predisposed him to the HAGL lesion.
The majority (68%) of the patients with HAGL lesions had associated abnormalities. A rotator cuff tear is the most common associated injury, 94% of which involve the subscapularis tendon. Other associated injuries in descending order of frequency are floating anterior inferior glenohumeral ligament, Hill-Sachs lesion, and tear of the glenoid labrum.
Liem T. Bui-Mansfield, Dean C. Taylor, John M. Uhorchak and Joachim J. Tenuta. Humeral Avulsions of the Glenohumeral Ligament: Imaging Features and a Review of the Literature. AJR 2002; 179:649-655