Comparison of surgical outcomes between fixation with hook plate and loop suspensory fixation for acute unstable acromioclavicular joint dislocation: a systematic review and meta-analysis

Treatment of acute (≤4 weeks) high-grade acromioclavicular (AC) joint separation (types III–VI) is still controversial. Currently, the two modern techniques that are widely used include hook plate fixation and coracoclavicular (CC) ligament fixation using a suspensory loop device (tightrope, synthetic ligament or absorbable polydioxansulfate sling). These techniques are both reported to have superior clinical outcomes. This systematic review and meta-analysis aimed to assess and compare clinical outcomes of hook plate fixation versus fixation of the CC ligament using a loop suspensory fixation (LSF) device for the treatment of AC joint injury. These clinical outcomes consist of the Constant–Murley score (CMS), pain visual analog score (VAS) and postoperative complications. Relevant comparative studies were identified from MEDLINE and Scopus from inception to October 5, 2015. Five of 571 studies were eligible; 5, 3, 3, and 5 studies were included in the pooling of CMS, pain VAS, surgical time and postoperative complications, respectively. The unstandardized mean difference (UMD) of the CMS for LSF was 4.43 [95 % confidence interval (CI) 0.73, 8.14], which was statistically significantly higher than the CMS in hook plate fixation. For VAS, the UMD was 0.02 points (95 % CI −3.54, 3.73) higher than LSF but without statistical significance. The surgical time of LSF was 16.21 min (95 % CI 6.27, 26.15) statistically significantly higher than hook plate fixation. LSF had a lower chance of postoperative complications by 0.62 units (95 % CI 0.30, 1.32) when compared to hook plate fixation, but this also was not statistically significant. In acute high-grade AC joint injuries, loop suspensory fixation had higher postoperative functional CMS and mean surgical time when compared to hook plate fixation. However, for postoperative VAS and complication rates, there were no statistically significant differences between groups.