Variations and morphometrics of palmaris longus in fetuses: a meta-analysis of cadaveric studies

The palmaris longus muscle, and its tendon, is one of the most variable muscles in humans. Though it has been extensively researched in the adult population, its variations and development in the fetal period were rarely investigated. The aim of this meta-analysis is to conduct an evidence synthesis on PL variations and the prevalence of its agenesis during intrauterine development. Seven studies met the inclusion criteria comprising 497 fetuses and 1027 fetal limbs. The true and crude weighted prevalence rates were of 81.2% and 77%, respectively. The bilateral and unilateral prevalence estimates were of 62.2% and 15%, respectively. No significant differences were found for side-based and gender-based prevalence values. There were significant frequency differences between the studied populations ( p