Is coracoclavicular reconstruction necessary in hook plate fixation for acute unstable acromioclavicular dislocation?

BACKGROUND: Acromioclavicular joint (ACJ) dislocation is a relatively common shoulder injury. For the treatment of cases of severe ACJ dislocation (Rockwood type III–V), hook plate fixation is an easy-to-master and minimally-invasive approach to surgical intervention. Over stress on the acromion following hook plate fixation often leads to acromial complications such as osteolysis and loss of reduction. We hypothesized that suspensory reconstruction alongside hook plate fixation might provide a superior stability and reduce complications as compared with hook plate fixation alone. The purpose of the study was to assess the clinical and radiographic outcomes of these two surgical modalities. METHODS: We retrospectively enrolled 49 patients with acute ACJ dislocation from May 2010 to December 2018. Among them, 19 patients received hook plate fixation only (HP group), and 19 underwent concomitant hook plate fixation and loop suspension fixation with two mersilene sutures (HM group). The demographic data of the patients were recorded and analyzed. All patients underwent a shoulder X-ray initially, immediately postoperatively, and at 1, 3, 6 and 12 months to measure the relative coracoclavicular distance (rCCD). Clinical assessment of shoulder function outcome was conducted using the Constant Murley Score (CMS); the University of California at Los Angeles (UCLA) Shoulder Score was also measured at the latest follow-up. RESULTS: There were no significant differences in the demographic data between the two groups. With regards to the CMS and the UCLA score, the HM group and HP group both had excellent outcomes, and no significant differences in scores were observed between groups (CMS: 93.90 ± 6.16 versus 94.47 ± 7.26, p = 0.47; UCLA score: 32.84 ± 2.91 versus 34.32 ± 1.16, p = 0.07). However, the HM group demonstrated substantial superiority in terms of maintenance of the rCCD over the HP group (91.47 ± 27.47 versus 100.75 ± 48.70, p = 0.015). In addition, there was less subacromial osteolysis in the HM group than the HP group (52.6% versus 15.8%, p = 0.038). CONCLUSION: Both fixations yielded excellent functional outcomes. However, concomitant hook plate fixation with loop suspensory reconstruction demonstrated the fewer acromion complications and statistical differences in reduction maintenance with less clinical significance.