disc degeneration grades on MR imaging showedan association with discographic grades. Type IV-V discs on discography, Grade IV-V disc on MR images, the presence of HIZ,and endplate abnormalities might indicate discogenic pain inpatients with chronic low back pain.

Objective To assess and compare the clinical outcomes and complications of TightRope® fixation vs hook plate fixation for the treatment of Rockwood III‐VI Acromioclavicular joint (ACJ) dislocations. Methods Relevant studies were identified by searching PubMed, Embase, and Web of Science databases, from their inception to 12 April, 2019. The main outcomes of interest included Constant Score, University of California Los Angeles (UCLA) Shoulder Score, Visual Analogue Scale (VAS), coracoclavicular distance (CCD), and complications. Weight mean difference (WMD) with 95% confidence intervals (95% CIs) or risk ratio (RR) with 95% CIs was used to calculate the data. Results Four studies with a total of 179 patients were included in this study. Compared with hook plate, TightRope® fixation was associated with a significantly less VAS score for pain (WMD = ‐0.69, 95% CI: −1.10, −0.27; P = 0.001). However, there were no significant differences between the two surgical techniques in terms of Constant Score (WMD = 6.12, 95% CI: −3.84, 16.08; P = 0.229), UCLA (WMD = 7.96, 95% CI: −5.76, 21.68; P = 0.256), CCD (WMD = 0.24, 95% CI: −0.67, 1.15; P = 0.602), and complication rate. Conclusion Both TightRope® and hook plate techniques offered effective outcomes in relieving the pain of dislocation and improving function of ACJ. However, TightRope® fixation showed an advantage over hook plate in terms of postoperative pain. Further larger‐scale RCTs are needed to verify our findings.