Comparison of Open vs. Mini-Open Approach in Treatment of Acute Acromioclavicular Joint Dislocation Using a Suspensory Fixation System: A Retrospective Cohort Study

Background/Objectives: Acromioclavicular (AC) joint dislocation is a common injury in young, active individuals, typically resulting from a direct shoulder impact. Treatment is guided by the Rockwood classification, with type III and higher injuries often managed surgically. Suspensory fixation systems are widely used, most commonly via a mini-open approach without direct visualization of the coracoid. This study compared clinical and radiological outcomes of open versus mini-open suspensory fixation in acute AC joint dislocation. Methods: This retrospective cohort study included patients treated surgically for Rockwood type III or higher AC joint dislocation between 2015 and 2021. Functional outcomes were assessed using Constant–Murley, ASES, and DASH scores. Pain, range of motion, and coracoclavicular (CC) distance were evaluated postoperatively and at final follow-up, including percentage difference compared with the contralateral side. Redislocation was defined as a ≥50% increase in CC distance (CCD). Complications, including cut-out, reoperations, and CC calcifications, were recorded. Results: Fifty-seven patients were included (mini-open n = 32, open n = 25; 52 men, 5 women). Mean age was 38.1 ± 13 years, with mean follow-up of 6.7 ± 1.5 years. The mini-open group had greater follow-up (90.1 [83.7–95.1]) than the open group (62.2 [60.3–75.4]). The mini-open group showed a significantly greater CCD at final follow-up (median [IQR] 14.7 [11.4–17.4] mm) compared with the open group (9.2 [7.8–11.1] mm). Redislocation occurred in 47% of mini-open versus 8% of open cases (p < 0.01). Functional scores, pain, and complication rates were similar between groups. Conclusions: Open suspensory fixation is associated with superior radiographic stability and lower redislocation rates compared to the mini-open approach, with comparable functional outcomes.