The prevalence of atypical bilateral trigger thumb in children: a systematic review and meta-analysis

Trigger thumb is a common hand condition in children, and the necessity of observing a period before surgery is debated due to factors such as the metachronism of bilateral lesions, inconsistent severity, and rates of spontaneous resolution. The exact prevalence of bilateral lesions in these cases remains uncertain. Understanding these rates could help avoid unnecessary surgeries and reduce anesthetic exposure. This systematic review defines atypical bilateral trigger thumb as either metachronous or exhibiting inconsistent bilateral lesions. Its aim is to estimate the overall prevalence of atypical pediatric bilateral trigger thumb and determine the optimal observation duration to prevent unwarranted surgeries.

This study followed the PRISMA guidelines and registered in the PROSPERO. The PubMed, Embase, and Cochrane Library databases were searched for all relevant studies up to August 2025. The Joanna Briggs Institute's quality assessment checklist was utilized to evaluate study quality. A random-effects meta-analysis was employed to synthesize prevalence rates from individual studies. Sensitivity and subgroup analyses were conducted to identify sources of heterogeneity and compare prevalence estimates.

A total of five studies were included for the final analysis, with 1240 pediatric trigger thumbs. Our final meta-analysis showed that the pooled prevalence estimate of atypical pediatric bilateral trigger thumb was determined to be 5.9% (95% CI 2.7- 12.3). Significant heterogeneity was observed across the studies included in this analysis (I² = 85%; P < 0.001). Subgroup analyses showed that the pooled prevalence of metachronisim and inconsistent degree was 3.4% (95% CI 2.5- 4.8, p < 0.001) and 10.7% (95% CI 3.1- 30.7, p = 0.002), respectively. Three studies reported the age at the first visit ranged from 20.1 to 31 months, while the period of metachronism spanned from 12 to 18 months.

Our study demonstrates that some cases of pediatric trigger thumb exhibit bilateral metachronism and varying degrees of severity, supporting a period of 12 to 18 months of observation before surgical intervention to minimize the risk of unnecessary or secondary procedures. Given the limited evidence in this systematic review and meta-analysis, it is imperative that future research includes rigorously designed, large-sample randomized controlled trials to strengthen the evidence base.

PROSPERO (CRD42024562483).