Management of Complex and Revision Anterior Shoulder Instability

Treatment of recurrent anterior shoulder instability has gained significant interest in recent years and involves evaluation of both glenoid and humeral sided bone loss. Decision making is more complex in patients with significant humeral or glenoid bone defects or in those who underwent previous instability surgery. Appropriate assessment of the glenoid track is necessary as "off track" lesions typically require treatments beyond arthroscopic labral repair alone. In those with significant humeral or glenoid sided bone loss, the authors recommend three-dimensional computed tomography in addition to magnetic resonance imaging for accurate evaluation. The Glenoid Track Instability Management Score is a useful guide to help direct treatment by using the glenoid track as well as other known risk factors for recurrence. In circumstances with significant glenoid bone loss, typically over 20%, a coracoid transfer such as the Latarjet is recommended. In patients that previously failed a coracoid transfer, the authors recommend a distal tibia allograft; however, distal clavicle and iliac crest autograft have also been reported to have high success rates. In those with large Hill-Sachs lesions, remplissage or bone grafting are recommended. An estimation of the postoperative glenoid track after glenoid bone augmentation is required for appropriate Hill-Sachs lesion treatment. The authors typically recommend against revision instability surgical treatment with arthroscopic repair alone.