Early clinical outcomes of standard and 3D-planned pre-bent hook plates versus suture-button fixation for acute Rockwood IIIB-V acromioclavicular dislocation with a Bigliani type II acromion: a retrospective cohort study.

BACKGROUND: Surgical management of acute high-grade (Rockwood IIIB–V) acromioclavicular joint dislocation (ACD) remains controversial. Standard clavicular hook plating (CHP) provides reliable reduction, but subacromial irritation/osteolysis and routine plate removal remain important concerns, particularly in patients with a Bigliani type II acromion. Three-dimensional (3D) planning may improve implant fit, whereas suture-button (SB) fixation represents a minimally invasive alternative. We compared Standard CHP, 3D-planned pre-bent CHP (3D-CHP), and SB fixation with respect to early recovery, subacromial morbidity, and secondary procedure burden. METHODS: We retrospectively reviewed 125 patients with acute high-grade ACD and a Bigliani type II acromion treated at a single center (CHP, n = 49; 3D-CHP, n = 33; SB, n = 43). The primary endpoint was VAS pain score at 3 months, and the key secondary endpoint was Constant–Murley Score (CMS) at 3 months. Additional outcomes included shoulder range of motion, coracoclavicular distance (CCD) and related radiographic events, subacromial erosion, complications, and secondary procedures within 24 months. RESULTS: Baseline characteristics were broadly comparable across groups. At 3 months, 3D-CHP and SB showed lower VAS pain scores and higher CMS than Standard CHP (both P < 0.05). By 24 months, pain, function, and radiographic maintenance were comparable across groups (all P > 0.05). Subacromial erosion was less frequent after 3D-CHP and absent after SB than after Standard CHP (P < 0.001). Planned plate removal accounted for most secondary procedures in the hook-plate groups, whereas unplanned reoperation was rare and did not differ significantly among groups (P = 0.144). SB subgroup outcomes were similar between Rockwood IIIB and pooled IV/V injuries. CONCLUSIONS: All three approaches achieved comparable 24-month functional and radiographic outcomes. The main between-technique differences appeared to concern early postoperative recovery, hook-related subacromial morbidity, and implant-related secondary procedure burden. Standard CHP provided reliable fixation, 3D-CHP may represent a refinement of hook-plate fixation aimed at improving implant–acromion conformity, and SB offered a less invasive alternative that avoided routine implant removal. CLINICAL TRIAL REGISTRATION: Not applicable.