HAGL Lesions

While the classic Bankart lesion involves the glenoid side of the IGHL complex, the HAGL lesion represents failure at the humeral insertion. It is a potent cause of anterior instability because the "hammock" of the IGHL is disabled.

History

• Event: Traumatic dislocation, classically high-energy (contact sport, fall, motor accident). Bokor's series found 94% had a violent first dislocation.
• Demographics: Tends to occur in slightly older patients than isolated Bankart instability, but is also seen in adolescents as an "atypical" lesion.
• Recurrence: Instability or apprehension with overhead/ABER activity.
• Pop: Patient may report a pop or tearing sensation deep in the axilla.
• Failed Surgery: Persistent instability after a "successful" Bankart repair that "never felt tight".

Always question the diagnosis in failed instability repairs and in any traumatic dislocation without a labral tear.

Physical Exam

• Apprehension: Positive in ABER.
• Relocation: Positive (Pain/Apprehension relief).
• Subscapularis: Check Lift-off / Belly-press (often associated tear).
• Axillary Nerve: ALWAYS verify sensation/deltoid function.

Clinically indistinguishable from Bankart instability without imaging.

The Apprehension test is sensitive but not specific for the type of lesion.

The clinical picture of "traumatic anterior instability" is shared by several lesions. The discriminator is almost always imaging and arthroscopy, not the bedside exam. Knowing how each entity differs determines where you place your anchors.

Intraoperative Complications

• Axillary Nerve Injury: The most feared complication. The nerve runs approximately 1-2 cm inferior to the capsule at the surgical neck. Both open and arthroscopic approaches place it at risk.
• Subscapularis Damage: During open approach, aggressive retraction or inadequate repair can lead to subscapularis insufficiency.
• Anchor Malposition: Anchors placed too high (cartilage) or too low (shaft) fail to restore anatomy.
• Inadequate Mobilization: Failure to release scarred tissue in chronic cases leads to insufficient repair.

Early Postoperative Complications

• Recurrent Instability: If repair fails or associated Bankart/bone loss missed.
• Stiffness: Specifically loss of External Rotation (capsular tightening).
• Infection: Standard surgical risk.
• Hematoma: Risk increased with subscapularis dissection.

Late Complications

• Chronic Instability: Often due to missed pathology or inadequate repair.
• Subscapularis Failure: Weakness in internal rotation and lift-off tests.
• Glenohumeral Arthritis: Long-term sequela of recurrent instability.
• Anchor Migration: Bioabsorbable anchor osteolysis or metal anchor loosening.

• Phase 1 (0-6 weeks):

  • Sling immobilization.
  • Limit External Rotation (to protect Subscap and HAGL repair) - usually less than 30 degrees.
  • Pendulums.

• Phase 2 (6-12 weeks):

  • Active Range of Motion.
  • Progress ER.

• Phase 3 (3-6 months):

  • Strengthening.
  • Return to sport at 6 months.

  Note: Rehabilitation is often slower than Bankart due to Subscapularis precautions (if open).

Outcomes by Repair Type

• Open Repair Success Rate: Greater than 90% stability restoration.
• Arthroscopic Repair: Variable (75-90%), highly surgeon and case dependent.
• BHAGL Repair: Excellent outcomes due to bone-to-bone healing.
• Floating IGHL Repair: Most challenging; may require combined open approach.

Functional Outcomes

• Return to Sport: 85-95% return to pre-injury level activity.
• Time to Return: Typically 6-9 months (longer than isolated Bankart).
• Range of Motion: External rotation may be slightly reduced (5-10 degrees).
• Strength: Full recovery expected if subscapularis healed properly.

Prognostic Factors

Long-Term Considerations

• Missed HAGL: 100% failure rate of Bankart repair when HAGL is present.
• Arthritis Risk: Ongoing instability leads to accelerated osteoarthritis.
• Re-dislocation: Low (less than 5%) if properly repaired and rehabilitated.

The evidence base for HAGL is built almost entirely on small case series, cadaveric work, and a handful of multicentre cohorts. There is no randomised trial, so several questions remain genuinely open.

• Open vs arthroscopic repair: There is no high-level comparative trial. Open deltopectoral repair remains the historical reference standard and is favoured when a subscapularis tear coexists or when the lesion is chronic and retracted. Arthroscopic repair is increasingly reported with good results in expert hands but is technically demanding. The MOON cohort showed HAGL is strongly associated with open surgery in current practice.
• Anchor position: Cadaveric data support placing anchors in the humeral neck rather than juxtachondrally to restore the anterior restraint, but the clinical magnitude of this difference is small and unproven in vivo.
• True incidence: Reported figures range from ~2% (MOON multicentre) to ~9% (early arthroscopic series) and up to 39% in the highly selected subgroup of violent first dislocation without a Bankart. The denominator drives the number; quote the population, not a single figure.
• MRI vs MR arthrography: HAGL is missed on roughly one-third of preoperative MRIs even in specialist centres. Whether routine MR arthrography or ABER positioning meaningfully closes that gap is not settled.
• Posterior (reverse) HAGL: A rare entity, usually linked to posterior instability, but recent data show it can accompany recurrent anterior dislocation and respond to arthroscopic repair. Its optimal management is still being defined.
• Role of non-operative treatment: Because the avulsed capsule retracts and the synovial environment limits healing, conservative management is generally reserved for low-demand patients, but the threshold is opinion-based rather than evidence-based.

Global Epidemiology

• HAGL accounts for roughly 2-9% of operatively treated anterior instability depending on the population studied (≈2.3% in the multicentre MOON cohort, ≈9% in early arthroscopic series).
• In the selected subgroup of a violent first dislocation without a Bankart lesion and no multidirectional laxity, incidence rises to ~39% (Bokor series).
• Predominantly affects young to middle-aged males injured in high-energy contact sport (rugby codes, football, wrestling) or trauma; also described as an "atypical" lesion in adolescents.

Society Guidance (side by side)

There is no dedicated international guideline for HAGL specifically; recommendations are extrapolated from anterior instability guidance and expert consensus.

Registry Notes

• Joint registries (NJR, AJRR, AOANJRR, Swedish, Norwegian) capture arthroplasty, not soft-tissue instability repair, so there is no large-scale registry survivorship data for HAGL repair. Evidence remains limited to case series and multicentre cohorts such as MOON.

High- vs Limited-Resource Practice Variation

• Well-resourced centres: ready access to MR arthrography, ABER-positioned MRI, 70-degree arthroscopes and accessory portals enables attempted arthroscopic repair.
• Limited-resource settings: reliance on plain radiographs and standard MRI increases the miss rate; open deltopectoral repair is often the pragmatic, reliable default and addresses any associated subscapularis tear in the same exposure.