A rare case of missed locked posterior shoulder fracture dislocation.

Posterior shoulder fracture-dislocation is a rare and often misdiagnosed injury leading to locked chronic dislocation and complicated management. Surgical management options vary based on chronicity, defect size, and patient-specific factors, with the modified McLaughlin procedure being a joint-preserving option for younger patients with large defects. We present a case of a 31-year-old male who had a missed locked posterior shoulder fracture-dislocation with a large reverse Hill-Sachs lesion, healed non-displaced proximal humerus fractures for >10 months following an electrical shock and fall. The patient underwent an open reduction and a modified McLaughlin procedure with lesser tuberosity transfer, resulting in significant symptom improvement and restored range of motion. Despite the often delayed diagnosis of posterior shoulder fracture dislocation, joint-preserving surgery such as modified McLaughlin procedure can restore function and improve quality of life in young patients with chronic injuries.