Surgical timing in neonatal brachial plexus palsy: A PRISMA-IPD systematic review

Background: Neonatal brachial plexus palsy (NBPP) is a serious complication of high-risk deliveries with controversy surrounding timing of corrective nerve surgery. This review systematically examines the existing literature and investigates correlations between age at time of upper trunk brachial plexus microsurgery and surgical outcomes. Methods: A systematic screening of PubMed, Cochrane, Web of Science, and CINAHL databases using PRISMA-IPD guidelines was conducted in January 2020 to include full-text English papers with microsurgery in upper trunk palsy, pediatric patients. Spearman rank correlation analysis and two-tailed t-tests were performed using individual patient data to determine the relationship between mean age at time of surgery and outcome as determined by the Mallet, Medical Research Council (MRC), or Active Movement Scale (AMS) subscores. Results: Two thousand nine hundred thirty six papers were screened to finalize 25 papers containing individual patient data (n = 256) with low to moderate risk of bias, as assessed by the ROBINS-I assessment tool. Mallet subscore for hand-to-mouth and shoulder abduction, AMS subscore for elbow flexion and external rotation, and MRC subscore for elbow flexion were analyzed alongside the respective age of patients at surgery. Spearman rank correlation analysis revealed a significant negative correlation (rho = -0.30, p < .01, n = 89) between increasing age (5.50 +/- 2.09 months) and Mallet subscore for hand-to-mouth (3.43 +/- 0.83). T-tests revealed a significant decrease in Mallet hand-to-mouth subscores after 6 months (p < .05) and 9 months (p < .05) of age. No significant effects were observed for Mallet shoulder abduction, MRC elbow flexion, or AMS elbow flexion and external rotation. Conclusion: The cumulative evidence suggests a significant negative correlation between age at microsurgery and Mallet subscores for hand-to-mouth. However, a similar correlation with age at surgery was not observed for Mallet shoulder abduction, MRC elbow flexion, AMS external rotation, and AMS elbow flexion subscores.