Is AC TightRope fixation better than Bosworth screw fixation for minimally invasive operative treatment of Rockwood III AC joint injury?

INTRODUCTION: Injuries to the acromioclavicular (AC) joint are common in sports participants and may lead to instability or degenerative changes that require surgical intervention. Diagnostics include X-ray projections; MRI could also be a useful method. Surgical treatment of acute Rockwood type III AC dislocation varies on a case-by-case basis and includes coracoclavicular (CC) stabilisation with two techniques of minimal invasive fixation: the Bosworth screw and AC TightRope fixation (Arthrex, US). The aim of this study was to analyse whether there is a difference between these two surgical procedures in the quality of repair of CC ligaments by comparing preoperative and postoperative AC joint radiological and clinical findings.

PATIENTS AND METHODS: In this study, we evaluated our 5 years' experience of surgical management of Rockwood type III AC dislocation. Radiological analyses included measurement of CC distance at the AC joint, X-ray and MRI evaluation of CC ligament scar tissue continuity; clinical outcome was assessed using the Constant Murley, Oxford Shoulder and DASH scores preoperatively and during 6 months of postoperative follow-up.

RESULTS: A total of 68 patients with Rockwood type III AC dislocation were treated surgically with minimally invasive CC fixation using either the AC TightRope implant (34 patients, TR group) or the Bosworth screw (34 patients, BS group) in a prospective, randomised clinical trial. There was no statistically significant difference in radiological X-ray and MRI evaluations of postoperative results between the two groups of patients at the end of follow-up. Patients in the TR group reported significantly less inconvenience with treatment as the patients in the BS group had to undergo a second operation to remove the Bosworth screw. Postoperative recurrence of dislocation was observed in two patients in the TR group (5.88%) and in four patients in the BS group (11.76%) 6 months postoperatively. The difference between the two groups was not statistically significant (p=0.4).

CONCLUSION: MRI could be a useful method to evaluate quality of repair of CC ligaments. The minimally invasive surgical techniques used in this study showed similar radiological and clinical efficacy in the treatment of acute Rockwood type III AC dislocation, but AC TightRope fixation provided patients with significantly more treatment satisfaction and less inconvenience than Bosworth screw fixation.