What is the treatment for a bony Bankart lesion, including changes visible on Magnetic Resonance Imaging (MRI)?

Treatment of Bony Bankart Lesions

For bony Bankart lesions, arthroscopic repair is the primary surgical treatment for lesions involving <15-20% of the glenoid diameter, while larger defects or chronic lesions with significant bone loss require bone grafting procedures (anatomical iliac crest graft or non-anatomical Latarjet/Bristow procedures). 1

Diagnostic Imaging Characteristics on MRI

Acute Setting

• MRI without IV contrast is preferred immediately after traumatic dislocation when posttraumatic joint effusion provides natural distention for adequate soft tissue visualization 2
• MRI performs comparably to CT in evaluating glenoid and humeral head bone loss, potentially eliminating the need for CT 2
• The bony Bankart fragment appears as an anteroinferior glenoid rim fracture with associated labroligamentous detachment 3

Subacute/Chronic Setting

• MR arthrography is the gold standard for imaging bony Bankart lesions in the subacute or chronic phase when joint effusion has resolved 2, 4
• MR arthrography provides sensitivity of 86-100% for labral injury detection and accurately assesses labroligamentous structures 2, 5
• CT arthrography serves as an alternative when MRI is contraindicated, with comparable sensitivity for labral lesions and superior visualization of osseous abnormalities like glenoid rim fractures 2, 4

Treatment Algorithm

Non-Operative Management

• Reserved for small, acute fractures (<15-20% of glenoid diameter) that are anatomically reduced after shoulder reduction 1
• Appropriate only for low-demand patients with minimal bone loss 3, 1
• High failure rates with conservative treatment in chronic fractures due to fragment resorption and bony erosion 1

Surgical Indications and Techniques

Arthroscopic Repair (Primary Option)

Indicated for:

• Acute bony Bankart lesions involving <15-20% of inferior glenoid diameter 1
• Young, active patients with recurrent anterior shoulder instability and documented Bankart lesion on MR arthrography 5
• Patients with positive apprehension test and clinical instability 5

Technical approach:

• The "bony Bankart bridge" (BBB) technique demonstrates 77% stability rate at mean 6.7-year follow-up with significant functional improvement (mean ASES score 93.1) 6
• Alternative arthroscopic technique uses traction sutures through an accessory anteromedial portal with knotless anchor fixation to reduce and secure the bony fragment 7
• Specialized instruments required to penetrate bone fragment within detached labrum 7

Open Bone Grafting Procedures

Indicated for:

• Acute fractures involving >15-20% of inferior glenoid diameter require bony fixation 1
• Chronic lesions with significant anterior glenoid bone loss 1
• Failed arthroscopic repair with persistent instability 3

Reconstruction options:

• Anatomical reconstruction: iliac crest bone graft or osteoarticular allograft 1
• Non-anatomical reconstruction: Latarjet or Bristow procedures 1

Critical Decision Points

Fragment Size Assessment

• The 15-20% threshold of inferior glenoid diameter is the primary determinant between arthroscopic repair versus bone grafting 1
• Quantify bone loss on MR arthrography or CT to guide surgical planning 5

Chronicity Considerations

• Acute lesions with anatomic reduction after shoulder reduction may heal non-operatively if small 1
• Chronic fractures managed case-by-case based on fragment resorption and bony erosion extent, with high recurrence under conservative therapy 1

Patient Risk Stratification

• Young male athletes in contact sports represent highest risk for recurrent instability and warrant initial Bankart repair even for first-time dislocations 3, 1
• High-risk patients should undergo early surgical intervention to prevent long-term instability 3

Common Pitfalls

• Underestimating bone loss on plain radiographs alone—always obtain MR arthrography or CT for accurate quantification 2
• Attempting arthroscopic repair on lesions >20% glenoid involvement leads to high failure rates 1
• Delaying treatment in young athletes increases risk of recurrent instability and progressive bone loss 3
• Using non-contrast MRI in chronic cases without adequate joint effusion results in suboptimal soft tissue assessment 2