Rockwood type VI acromioclavicular joint dislocations: A systematic review

Importance: Rockwood (RW) type VI acromioclavicular (AC) dislocations are exceptionally rare injuries, often associated with high-energy trauma and polytrauma. Limited evidence exists regarding their optimal management and long-term outcomes, making it crucial to synthesize available data to guide clinical decision-making. Aim/objective: This study aims to systematically review existing literature on patient demographics, mechanisms of injury, treatment strategies, functional and radiographic outcomes, and complications of reported cases of RW type VI acromioclavicular (AC) injuries. Evidence review: A comprehensive literature search was conducted in multiple databases on February 5, 2025. Eligible studies included retrospective and prospective reports of patients with RW type VI AC dislocations. Case reports and case series were considered, given the rarity of the condition. Data extracted included demographics, mechanism of injury, treatment methods, functional outcomes, radiographic results, and complications. Due to the limited number of cases and heterogeneity of reporting, a qualitative synthesis was performed without formal meta-analysis. Findings: Twenty-four patients were identified across 20 case reports and 2 case series. Among them, 10 were classified as RW type VIa (subacromial) and 14 as type VIb (subcoracoid). The predominant mechanism of injury was motor vehicle accidents. Surgical intervention was the treatment of choice in 91.7% of cases, with techniques including K-wire fixation and coracoclavicular ligament repair. Two patients with type VIa dislocations experienced spontaneous reduction without surgical intervention. At follow-up, 21 of 24 patients regained full range of motion and reported pain-free function, accompanied by satisfactory radiographic findings. The overall complication rate was 8.3%, comprising persistent pain and muscle atrophy. No cases of recurrent dislocation or infection were reported. Hardware removal was performed in 45.8% of patients. Conclusion: RW type VI AC dislocations remain exceedingly rare, with only 24 cases reported to date. Subclassification into type VIa and VIb may assist orthopedic surgeons in tailoring management strategies due to differences in associated injury patterns. While the majority of cases are surgically managed, no single treatment approach demonstrates clear superiority. Overall outcomes appear favorable regardless of intervention, with high rates of return to function and low complication rates. Awareness of this injury pattern is essential to prevent missed diagnoses in the acute trauma setting. Future high-quality, multicenter studies are necessary to establish evidence-based treatment recommendations. Level of evidence: V. Systematic reviews and meta-analyses are assigned a level of evidence equivalent to the lowest level of evidence used from the manuscripts analyzed (case series).