Clinical efficacy, radiographic outcomes, and safety of tunnel-less versus single-tunnel suspension fixation in the treatment of acromioclavicular joint separation: A retrospective comparative study

This study aims to compare clinical efficacy, radiographic outcomes, and safety of tunnel-less and single-tunnel suspension fixation for acromioclavicular joint separation. From January 2019 to June 2023, 45 patients with acute Rockwood type III-V acromioclavicular joint separations were retrospectively analyzed. Cases were divided into coracoid single-tunnel fixation (n = 21) and tunnel-less suspension fixation (n = 24) groups. Open surgical techniques were used in both groups. Operative time, incision length, blood loss, Constant-Murley scores, pain visual analog scale, American Shoulder and Elbow Surgeons scores, and coracoclavicular (CC) distance were compared at preoperative, immediate postoperative (for CC distance), 3-month, and final follow-up (mean 9.1 months). Complications were evaluated. The tunnel-less group had shorter operative times (46.76 ± 5.01 vs 64.70 ± 5.72 minutes, P < .001) but similar blood loss and incision lengths (P > .05). Preoperative CC distances were similar. Postoperatively, both groups achieved significant reduction (single-tunnel: 9.7 ± 1.1 mm; tunnel-less: 9.4 ± 0.9 mm, P = .287). At final follow-up, CC distances were 11.6 ± 2.5 mm and 10.3 ± 1.3 mm, respectively (P = .068). At 3 months, Constant-Murley scores were higher in the tunnel-less group (85.80 ± 2.22 vs 84.70 ± 1.75, P = .008), though differences in visual analog scale and American Shoulder and Elbow Surgeons were nonsignificant. No clinically significant differences in functional scores were observed at final follow-up. One coracoid fracture and 1 re-dislocation occurred in the single-tunnel group; no intraoperative or major postoperative complications occurred in the tunnel-less group. Both techniques achieved reliable fixation and functional recovery. Tunnel-less fixation required shorter operative time, avoided coracoid tunneling, and demonstrated a superior safety profile by reducing iatrogenic fracture risk and showing a trend towards better maintenance of radiographic reduction.