A Rare Case of Rotator Cuff Interposition Causing Humeral Head Subluxation Following Anterior Shoulder Dislocation

This case report aims to highlight that not all shoulder dislocations are simple to treat and that early recognition of complications is key in managing these injuries successfully. We report the case of a 68-year-old gentleman who presented to Accident and Emergency (A&E) following a fall and sustaining an anterior dislocation of his right shoulder. This was reduced under sedation; however, the patient had an ongoing feeling that his shoulder "was not right." The subsequent investigation demonstrated persistent anterior subluxation of the humeral head with rotator cuff interposition in the glenohumeral joint. This case appears to be the first of its kind to be reported in which the supraspinatus, subscapularis, and long head of biceps were collectively interposed. This was treated operatively with open reduction and rotator cuff repair, even though the procedure was technically difficult due to tissue fibrosis and the formation of adhesions. The patient progressed well and had a good clinical outcome. This case highlights that rotator cuff interposition following shoulder dislocation is a rare but debilitating complication and is often neglected in initial care. We must recognise that patients are their own experts, and if they report something is "not right," further investigation and prompt treatment are required.