Coracoid clavicular tunnel angle is related with loss of reduction in a single-tunnel coracoclavicular fixation using a dog bone button in acute acromioclavicular joint dislocation

Abstract

PurposeDespite the high failure rates of techniques used to maintain the reduction of single‐tunnel coracoclavicular (CC) fixation, analyses of the etiology of loss of reduction related to surgical techniques are limited. Therefore, it was hypothesized that the initial coracoclavicular tunnel angle was related to loss of reduction in the single‐tunnel technique for AC joint dislocation. This study aimed to evaluate the clinical and radiological outcomes of arthroscopic single‐tunnel CC suture button fixation according to the initial coracoclavicular tunnel angle. MethodsThirty‐two consecutive patients who underwent arthroscopic single‐tunnel CC suture button fixation for AC joint dislocation from 2014 to 2018 were enrolled. The tunneling‐first technique was used in the first 11 patients, while the reduction‐first technique was used in the remaining 22 consecutive patients. For clinical assessments, the American Shoulder and Elbow Surgeons (ASES) score and Korean Shoulder Score (KSS) were recorded. For radiological evaluation, coracoclavicular distance ratio, coracoclavicular tunnel angle, coracoid, and clavicular tunnel widths were measured. ResultsThe ASES score did not differ significantly between the two groups (n.s.). However, the KSS was significantly better in the reduction‐first group (p = 0.031). No significant intergroup differences were observed in the pre‐ and postoperative coracoclavicular distance ratio. However, at the last follow‐up, loss of coracoclavicular distance ratio was significantly smaller in the reduction‐first group (p < 0.001). At the final follow‐up, loss of the coracoclavicular distance ratio was positively correlated with the postoperative coracoclavicular tunnel angle (p < 0.001, Spearman’s rho correlation coefficient = 0.602). The final follow‐up clavicular tunnel width was also significantly smaller in the reduction‐first group (p = 0.002). Finally, the last follow‐up clavicular tunnel width was positively correlated with the postoperative coracoclavicular tunnel angle (p = 0.008, Spearman’s rho correlation coefficient = 0.459). ConclusionThe reduction‐first technique showed better clinical and radiological outcomes than the tunneling‐first technique in single‐tunnel CC fixation for AC joint dislocation. A large postoperative coracoclavicular tunnel angle was associated with loss of reduction and clavicular tunnel widening. Therefore, obtaining a straight coracoclavicular tunnel angle is crucial for achieving better outcomes and minimizing loss of reduction. Level of evidenceIII.

Functional and Radiographic Outcomes of Intraoperatively Decreasing the Coracoclavicular Distance to 50% of the Unaffected Side in Stabilization of Acute Acromioclavicular Joint Injury: A Retrospective Evaluation

“…The investigators found that the clavicular tunnel widths were widened from 4.5 to 11.4 mm 34 and from 6 to 10 mm, 15 respectively. Additionally, Seo et al 28 reported that tunnel widening was related to the CC tunnel angle. In our study, we found the mean widths of the medial and lateral clavicular tunnels to be 5.03 ± 0.68 and 4.47 ± 0.67 mm, respectively, an increase of approximately 100% from the initial clavicular tunnels.…”

“…The authors of that study hypothesized that the problem resulted from slippage of the suspension sutures and/or the postoperative clavicular tunnel angle leading to tunnel widening. 28 There are 2 common techniques used in CC stabilization: the single clavicular tunnel technique and the double clavicular tunnel technique. The double-tunnel technique has fewer complications than the single-tunnel technique and has a higher success rate in terms of clinical and radiographic outcomes.…”

“…Postoperative clavicular tunnel widening has been reported in several studies. 16,19,28,34 Jensen et al 15 and Yoo et al 34 reported postoperative clavicular tunnel widening in patients with acute and chronic AC joint injury who had undergone single-tunnel CC stabilization. The investigators found that the clavicular tunnel widths were widened from 4.5 to 11.4 mm 34 and from 6 to 10 mm, 15 respectively.…”

Treatment of acute high-grade acromioclavicular joint dislocation

“…Despite these favorable results, the use of two metallic CC suspension devices risks fracture of the clavicle or coracoid process due to the non-negligible diameter of the drill holes, 4.0 mm [ 33 - 35 ]. Martetschläger et al [ 36 ] showed that 20% of the fractures of the clavicle or coracoid process were related to complications resulting from technical errors in the drilling technique.…”

Novel Double Endobutton Technique Combined with Three‐Dimensional Printing: A Biomechanical Study of Reconstruction in Acromioclavicular Joint Dislocation

“…A larger amount of widening was correlated with increased AP and rotational laxity 16,25 . Thus, the anatomical position of the sutures and buttons has a crucial role against rotational and shear forces 42,43 .…”