Ulnar Nerve In Situ Decompression versus Transposition for Idiopathic Cubital Tunnel Syndrome: An Updated Meta-Analysis.

Purpose Evidence for the superiority of in situ simple decompression (SD) versus ulnar nerve transposition (UNT) for cubital tunnel syndrome remains controversial. The purpose of this study was to compare the clinical improvement, complication rate, and revision rate of SD versus UNT using the available evidence. Materials and Methods We performed a literature search of relevant publications using PubMed, SCOPUS, Cochrane Library, and Springer Link. Inclusion criteria included (1) adult patients >18 years of age, (2) idiopathic cubital tunnel syndrome, (3) primary comparison studies including both SD versus UNT with discrete data for each procedure, (4) average follow-up of at least 2 months, and (5) a full English language manuscript available. Odds ratios of improvement, complications, and revision surgery after SD compared with UNT were calculated. Data were analyzed using both fixed and random effects models, and studies were assessed for publication bias and heterogeneity. Results A total of 1,511 articles from 1970 to 2017 were identified before inclusion, and exclusion criteria were applied. Ultimately 17 studies met the inclusion criteria and included 2,154 procedures. Of these, 1,040 were SD, and 1,114 were UNT procedures. Study heterogeneity was low. Odds ratios of clinical improvement and revision surgery with SD versus UNT were not significantly different. The odds ratio of complications with SD versus UNT was 0.449 (95% confidence interval [CI] of 0.290-0.695) and 0.469 (95% CI of 0.297-0.738) for fixed and random effect models, respectively. The difference in complications between SD versus UNT was significant ( P < 0.001). Conclusion There is no statistically significant difference in clinical outcomes or rate of revision surgery between SD versus UNT. However, there were significantly more complications with UNT. The current body of evidence regarding cubital tunnel syndrome lacks prospective, randomized, controlled trials, uniform reporting of indications, and standardized outcome scoring.