Arthroscopically assisted stabilization versus hook plate fixation for chronic acromioclavicular joint separation: Short-term follow-up of a prospective multicenter study

Abstract

Background: Chronic acromioclavicular (AC) joint instability may result after failed surgical or non-operative treatment of acute AC joint dislocation. Data on clinical outcomes of chronic AC joint instability are limited; thus, no gold standard surgical technique exists. Objective: This study aimed to evaluate clinical and radiological results after arthroscopically assisted or hook plate stabilization of chronic type III–V AC joint instability. We hypothesized that (1) operative treatment would improve outcomes in short-term follow-up (2) without a difference between the groups. Materials and methods: Five level I trauma centers prospectively included patients in this non-randomized multicenter study. Patients had undergone reconstruction of the coracoclavicular (CC) and AC ligaments with an anatomic hamstring autograft. Graft healing was supported by arthroscopically assisted AC joint stabilization using a flip button or by a hook plate. Inclusion criteria were chronic high-grade (Rockwood III–V) AC joint instability and failed surgical or non-operative treatment after a trial of conservative management measures ≥12 weeks. Functional outcome measures (Subjective Shoulder Value, Constant Score, Taft Score, Acromioclavicular Joint Instability Score) were recorded preoperatively and at follow-up. Radiographs were performed pre- and postoperatively, and at follow-up. Results: A total of 43 patients were included (mean age 44 ± 12 years, range 18–64; 17, 40%, Rockwood III and 26, 60%, Rockwood V; 32, 74%, arthroscopic and 11, 26%, hook plate; 35 available for follow-up; mean follow-up 12 ± 3 months, range 6–20). All clinical outcome measures improved significantly (p < 0.001), with no differences between the groups. CC distance improved significantly from pre- to postoperative (19 ± 5 mm to 8 ± 2 mm; p < 0.001) but was lost at follow-up (13 ± 4 mm; p < 0.001). Two patients were revised after arthroscopic stabilization. All patients with hook plate stabilization required additional surgery for implant removal. Conclusion: Surgical treatment for symptomatic chronic AC joint instability improves clinical outcomes in short-term follow-up. Functional results of arthroscopically assisted and hook plate stabilization are comparable. Nonetheless, some loss of reduction can be observed. Level of evidence: IV.