Radiographic alterations in clavicular bone tunnel width following anatomic coracoclavicular ligament reconstruction (ACCR) for chronic acromioclavicular joint injuries.

Purpose: To evaluate tunnel widening and its relationship in loss of reduction and clinical outcomes in patients undergoing anatomic coracoclavicular ligament reconstruction (ACCR) using free tendon grafts for chronic acromioclavicular (AC) joint injuries.
Methods: A retrospective chart review was performed on patients undergoing ACCR for type III-VI AC joint injuries between January 2003 and December 2017. For radiographic analysis, pre- and post-operative coracoclavicular distance (CCD) and tunnel width of the medial and lateral clavicular bone tunnel were measured at the earliest (EPO) and latest postoperative follow-up (LPO). To determine the clinical relevance of improvement in clinical outcome score (American Shoulder and Elbow Surgeons score) substantial clinical benefit (SCB), and patient acceptable symptomatic state (PASS) thresholds were used.
Results: Twenty-four patients with a mean clinical follow-up of 37 ± 35 months (mean age 44.7 ± 13.4) were included in the study. Both the medial (5.6 ± 0.2 mm _EPO -6.6 ± 0.7 mm _LPO; p < 0.001) and lateral (5.6 ± 0.5 mm _EPO -6.8 ± 1 mm _LPO ; p < 0.001) clavicular bone tunnel showed significant widening from EPO to LPO. There was a significant loss of reduction at LPO (CCD _LPO 10.1 ± 4 mm) compared to EPO (CCD _EPO : 6.2 ± 3.8 mm) (p < 0.001). No significant correlation between loss of reduction and medial (p = 0.45; r = - 0.06) or lateral (p = 0.69; r = - 0.06) tunnel widening was found. Alterations in tunnel width were shown having no influence on clinical outcomes.
Conclusion: Patients who underwent ACCR using a free tendon graft for the treatment of chronic type III-VI ACJ injuries showed significant clavicular bone tunnel widening during the postoperative course. No correlation between tunnel widening and loss of reduction was shown with radiographic findings having no influence on clinical benefit and satisfaction.
Study Design: Case Series; Level of evidence, IV.