Bankart Lesion

A Bankart lesion is avulsion of the anteroinferior glenoid labrum together with the anterior band of the inferior glenohumeral ligament from the glenoid rim. It occurs in over 90% of traumatic anterior shoulder dislocations in young patients. Variants:

• Bony Bankart: a fragment of the glenoid rim
• ALPSA: the labrum and periosteum slide medially on the neck of the glenoid
• Perthes: periosteum stripped but not displaced
• Glenolabral articular disruption: labral tear with a cartilage flap

Epidemiology: dislocation in 1 to 2% of people, peaking at 15 to 30 years, with a male predominance. After a first dislocation, recurrence is 60 to 90% in patients under 20 and about 10 to 15% over 40. Risk factors for recurrence are age under 25, contact sport, hyperlaxity, glenoid bone loss and an engaging humeral head defect. Glenoid bone loss over about 15 to 20% of width converts the glenoid to an inverted pear and is the critical threshold for soft tissue repair failure.

Complications: recurrent instability, instability arthropathy, axillary nerve palsy (about 10 to 30%, usually transient), cuff tear in patients over 40, and vascular injury.

• Acute: severe pain, arm held in slight abduction, a squared shoulder with a palpable humeral head anteriorly, and inability to rotate
• Check axillary nerve sensation over the lateral deltoid, radial pulse, and motor function of the hand
• Chronic: apprehension with the arm abducted and externally rotated, relief with posterior pressure (relocation test), and a positive anterior load and shift test
• Red flags: associated fracture, neurovascular deficit, a first dislocation over 40 (screen for cuff tear), a locked dislocation, and a seizure or electric shock mechanism (posterior dislocation)

• Radiographs before and after reduction: anteroposterior, scapular Y and axillary views. West Point view for bony Bankart.
• CT with three dimensional reconstruction (humeral head subtracted): quantify glenoid bone loss as a percentage of the glenoid width and the size of the fragment.
• MR arthrography or MRI: labral and ligamentous detachment, ALPSA, cuff and capsule.
• Ultrasound for cuff tear in older patients.
• Electromyography at 3 to 4 weeks for persistent nerve deficit.

Differentials: posterior dislocation, proximal humerus fracture, superior labral tear, multidirectional instability, acromioclavicular injury, cuff tear.

Reduction:

• Analgesia and relaxation with intra articular lidocaine 1% 10 to 20 mL, or procedural sedation (propofol 1 mg/kg IV then 0.5 mg/kg boluses with monitoring).
• Techniques: traction with counter traction, scapular manipulation, or external rotation methods. Avoid forceful leverage, which causes fracture and nerve injury.
• Repeat the neurovascular examination and radiographs afterwards.

After reduction:

• Sling for 1 to 3 weeks in a comfortable position, then early motion.
• Paracetamol 1 g orally every 6 hours and ibuprofen 400 mg orally every 8 hours with food for up to 7 days.
• Rehabilitation for 3 months: cuff and scapular strengthening.

Surgery:

• First dislocation under 25 years in contact or overhead sport, recurrent instability, a displaced bony fragment over 20%, or failed rehabilitation.
• Arthroscopic Bankart repair with 3 or more suture anchors and capsular plication, in glenoid bone loss under about 15%.
• Open Bankart repair in high risk contact athletes.
• Glenoid bone loss over 15 to 20% or an engaging humeral defect: Latarjet procedure (coracoid with conjoint tendon fixed to the anterior glenoid with two 3.5 to 4.0 mm screws), or a bone block graft.
• Cefazolin 2 g IV before incision (3 g if over 120 kg).
• Postoperative: sling for 3 to 4 weeks with limited external rotation for 6 weeks, non-contact sport at 4 to 6 months, and contact sport at 6 to 9 months.

Outcomes: recurrence is 5 to 15% after arthroscopic repair (higher with bone loss in contact athletes) and 2 to 5% after Latarjet.

Complications: stiffness, recurrence, screw problems, graft nonunion (5 to 10%), musculocutaneous or axillary nerve injury, infection and arthritis.

Follow up at 2 and 6 weeks, 3, 6 and 12 months. Counsel on avoiding forced abduction and external rotation until healed.