Subacromial Distal Clavicle Dislocation with Associated Scapular Spine Fracture: A Case Report.

Introduction: Inferior or subacromial dislocation of the distal clavicle is a rare entity. Previous reports of this injury pattern have largely been limited to Rockwood VI acromioclavicular joint (AC) dislocations, with the distal clavicle located in the subcoracoid position. Few case reports have been described with the inferior clavicle being located in the subacromial space, and these have all been previously associated with clavicle fractures. To our knowledge, no previous case report exists in the literature with this AC joint injury and associated scapular spine fracture.

Case report: Here, we report on a case of a 30-year-old right-hand dominant African American male who suffered a high-energy left-sided inferior distal clavicle dislocation with an associated scapular spine fracture that was successfully treated with open reduction of the AC joint dislocation, followed by open reduction and internal fixation (ORIF) of the scapular spine fracture. After ORIF of the scapular spine and reduction of the AC joint, the AC joint was deemed to be a capsular injury with intact ligaments, so a simple capsular repair was performed. We also summarize the existing literature on this topic.

Conclusion: Inferior dislocation of the clavicle into the subacromial space with an associated scapular spine fracture is an extremely rare injury which has not been previously reported. This injury can successfully be managed by first reducing the AC joint, and then proceeding with anatomic reduction and fixation of the scapular spine with good functional result. The ligaments surrounding the AC joint in the subacromial pattern are often intact, and the dislocation is a result of capsular injury. This leads us to believe that subtyping the Rockwood VI classification to VIa (subacromial) and VIb (subcoracoid) would be useful for orthopedic surgeons due to differences in associated injury and subsequent operative management.