Review Question - QID 212194

Figure A is the radiograph of a 76-year-old female who presents to your office with complaints of right shoulder pain for the past 6 years. She has tried several course of physical therapy and cortisone injections without relief. On examination, her active and passive forward elevation are 50 and 150 degrees, respectively. She has active and passive external rotation with her arm at her side of -10 and 40 degrees, respectively. She has a positive hornblower's sign. She undergoes a reverse shoulder arthroplasty with a tendon transfer (labeled A in Figure B). Which nerve is most at risk when performing the tenotomy for transfer?