Review Question - QID 217830

You performed an aTSA in a 67-year-old male 6 months ago and the patient follows up in your office with complaints of new shoulder pain and popping. He feels like his shoulder clicks with overhead range of motion. On examination there is a palpable click with forward elevation. He has 80º of external rotation in adduction and 5/5 strength with empty can testing. Sensation is intact throughout the upper extremity. His incision is well-healed with no signs of erythema or swelling. His axillary radiograph is seen in Figure A. What is the most likely complication which has occurred?