Review Question - QID 218146

A 68-year-old female presents to your clinic with long-standing right shoulder pain. She reports having a fall from a ladder 6 years ago and having "issues" with her shoulder since that time. Figure A demonstrates her examination when asked to abduct her shoulder. However, you are able to passively abduct her shoulder to 160°. She can externally rotate to 30° with the arm at her side and can internally rotate to her right hip. She denies any paresthesias. She has done 6 weeks of physical therapy and had one corticosteroid injection without any pain relief or change in function. Radiographs obtained in your office demonstrate acetabularization of the acromion and moderate arthritis of the glenohumeral joint. You discuss with her that her best option is reverse total shoulder arthroplasty (rTSA), due to the cause of her shoulder dysfunction. Which of the following best describes this pathologic process?