Conservative treatment of Rockwood type III acromioclavicular joint separation: a randomized controlled trial sling vs. brace

BACKGROUND: Management of Rockwood III acromioclavicular joint separations is a matter of ongoing debate, with nonoperative treatment being favored in recent literature. The aim of this study is to compare clinical and radiological outcomes of nonoperative treatment with a brace, which elicits a direct reduction force to the distal clavicle, to a sling. We hypothesized the brace might yield in better acromioclavicular joint (ACJ) reduction and cosmesis. METHODS: In this dual center prospective randomized controlled trial, all patients sustaining an acromioclavicular joint separation Rockwood III between July 2017 and August 2020 were included. Patients with previous ipsi- or contralateral ACJ injury or surgery were excluded. Randomization occurred in the emergency department to either the sling or brace group. Patients were followed up at 1, 6, and 12 weeks. Patient-reported outcome measures included subjective shoulder value (SSV) and American Shoulder and Elbow Surgeons (ASES) score at each follow-up and Constant Score at 6 and 12 weeks. Vertical distal clavicle displacement was assessed on bilateral non-weighted panoramic anteroposterior radiographs using coracoclavicular (CC) distance to calculate the CC-index. RESULTS: Thirty-five consecutive patients were included across the 2 sites, 18 (all male) in the brace and 17 (14 male) in the sling group. Baseline characteristics did not differ significantly between groups, the average age was 40 years, and body mass index 25.5 kg/m(2). Analysis revealed no statistical difference in CC-index between groups at the time of injury, 6 weeks and 12 weeks postinjury (P = .39, P = .11, and P = .21). SSV improved from 30 and 35 postinjury to 81 and 84 at 12 weeks in the sling and brace group, respectively (P = .59). ASES improved from 48 and 38 to 82 and 83, respectively (P = .84). Similarly, Constant Score improved from 64 and 67 to 82 and 81, respectively (P = .90). One patient in the brace group underwent ACJ stabilization with hamstring autograft at 4 months due to persistent pain. CONCLUSION: This randomized controlled trial shows no statistically significant difference between the brace and sling group in clinical (SSV, ASES, Constant Score) or radiological (CC-index) outcomes after conservative treatment of Rockwood III injuries.