Operative versus non-operative treatment of ulnar styloid process base fractures: a systematic review and meta-analysis

Purpose: Ulnar styloid process (USP) fractures are present in 40–65% of all distal radius fractures (DRFs). USP base fractures can be associated with distal radioulnar joint (DRUJ) instability and ulnar sided wrist pain and are treated by conservative management and surgical fixation, without consensus. This systematic review and meta-analysis compares operative to non-operative treatment of concomitant ulnar styloid base fractures in patients with distal radius fractures. Methods: PubMed/Medline/Embase/CENTRAL databases were searched identifying RCTs and comparative observational studies. Effect estimates were extracted and pooled using random effect models to account for heterogeneity across studies. Results were presented as (standardized) mean differences (SMD or MD) or odds ratios (OR) and corresponding 95% confidence intervals (95%CI). Results: Two RCTs (161 patients) and three observational studies (175 patients) were included. Tension band wiring was used for surgically treated USP fractures. Results were comparable across the different study designs and hence pooled across studies. Non-surgically treated patients had better wrist function at 6 months (SMD 0.57, 95%CI 0.30; 0.90, I² = 0%). After 12 months there was no observed difference (MD 2.31, 95%CI −2.57; 7.19, I² = 91%). Fewer patients had USP non-unions in the operative group (OR 0.08, 95%CI 0.04; 0.18, I² = 0%). More patients suffered complications in the operative group (OR 14.3; 95%CI 1.08; 188, I² = 89%). Conclusion: Routinely fixating USP base fractures as standard of care is not indicated. Surgery may be considered in selective cases (e.g. persistent DRUJ instability during ballottement test after fixation of the radius).