Humeral avulsion of the glenohumeral ligament
Humeral avulsion of the glenohumeral ligament (HAGL) is, as the name suggests, avulsion of the inferior glenohumeral ligament (IGHL) from its humeral insertion. It can be associated with a bony avulsion fracture in which case it is referred to as bony humeral avulsion of the glenohumeral ligament (BHAGL lesion).
HAGL is much more frequent in young men engaged in contact sports.
Clinical presentation is usually with a history shoulder dislocation. Anterior shoulder pain, apprehension in abduction and lateral rotation, subjective instability and crepitus are noted on examination.
HAGL most often results from anterior shoulder dislocation due to forced hyperabduction and external rotation of the arm.
- bony avulsion from the medial cortex of the humeral neck, and when combined with a Bankart lesion are often termed a “floating” inferior glenohumeral ligament: may be seen in ~ 20% of cases
MRI is the modality of choice for assessment of HAGL, especially as the finding may be difficult to diagnose on arthroscopy. Typical findings include:
- avulsion of the IGHL from the proximal humerus
- it is important to note that failure of the IGHL is more frequent at its glenoid insertion (40%) or midsubstance (35%), with only 25% tearing at the humerus
- retraction of the IGHL (so called J sign): the normal U-shaped inferior glenohumeral recess is disrupted 2
- other findings associated with anterior shoulder dislocation are found in 65% cases 2, including:
Treatment and prognosis
Shoulder instability as a result of HAGL lesions is reported to occur in ~5% (range 2-10%) 2.
The degree of instability and presence of other associated injuries determines whether surgical repair is required.
- 1. Kaplan P. Musculoskeletal MRI. W B Saunders Co. (2001) ISBN:0721690270. Read it at Google Books - Find it at Amazon
- 2. Carlson CL. The "J" sign. Radiology. 2004;232 (3): 725-6. doi:10.1148/radiol.2323021239 - Pubmed citation
- 3. Liavaag S, Stiris MG, Svenningsen S et-al. Capsular lesions with glenohumeral ligament injuries in patients with primary shoulder dislocation: magnetic resonance imaging and magnetic resonance arthrography evaluation. Scand J Med Sci Sports. 2011;21 (6): e291-7. doi:10.1111/j.1600-0838.2010.01282.x - Free text at pubmed - Pubmed citation
- 4. Melvin JS, Mackenzie JD, Nacke E, Sennett BJ, Wells L. MRI of HAGL lesions: four arthroscopically confirmed cases of false-positive diagnosis. (2008) AJR. American journal of roentgenology. 191 (3): 730-4. doi:10.2214/AJR.07.3631 - Pubmed
- 5. Roy EA, Cheyne I, Andrews GT, Forster BB. Beyond the Cuff: MR Imaging of Labroligamentous Injuries in the Athletic Shoulder. (2016) Radiology. 278 (2): 316-32. doi:10.1148/radiol.2015150364 - Pubmed