Atypical presentation of an inferior shoulder dislocation with an engaging Hill-Sachs lesion: A case report

Inferior shoulder dislocations (ISD) are very rare occurrences estimated to make up only 0.5% of all shoulder dislocations and are typically associated with high-energy trauma and humerus fractures. We present an unusual case of an ISD due to the absence of the pathognomonic arm posture, mimicking an anterior shoulder dislocation. After multiple failed attempts at closed reduction in the Emergency Department, orthopaedics was consulted for further evaluation. Appropriate imaging was ordered, including an axillary radiograph and CT scan, which demonstrated an ISD with an engaging Hill-Sachs lesion and displaced greater tuberosity fracture. The patient was taken to the operating room the same day and underwent a successful closed reduction utilizing intraoperative fluoroscopic imaging.

Early reduction of ISD is critical to preventing complications, such as axillary neuropraxia and brachial plexopathy. However, closed reduction of ISD is often difficult. The two-step maneuver under general anesthesia in the operating room with procedural fluoroscopy is recommended to ensure a safe, adequate, and timely reduction.