後方肩関節不安定症：症例シリーズにおける提示と治療成績のスペクトラム

Posterior shoulder dislocation is an uncommon condition, accounting for a minority of shoulder instability cases. It is more frequently encountered in high-level athletes and is often missed at initial presentation, which can lead to chronic instability and recurrent dislocations. Predisposing factors include congenital anatomical variations, capsular laxity, and acquired injuries such as trauma or tetanic muscle contractions during seizures or electrical shocks. Management strategies are broadly divided into conservative and surgical approaches. Nonoperative treatment focuses on strengthening the periscapular and rotator cuff musculature but has limited success in traumatic cases and in athletic patients, where long-term instability is more likely. Surgical options aim to address the underlying pathology and may be performed using open or arthroscopic techniques. Soft tissue procedures include labral repair and capsular plication, whereas bony procedures may involve corrective osteotomies in cases of congenital abnormalities or bone grafting to address reverse Hill-Sachs lesions resulting from humeral head impaction on the glenoid. We present a three-case series of posterior shoulder dislocations managed at a teaching hospital in the United Kingdom. This series highlights the spectrum of posterior shoulder instability, the multidisciplinary approach required, and the outcomes achieved with differing management strategies.