Prevalence of Neural Axis Abnormalities in Typical and Atypical Laterality Idiopathic Scoliosis: A Systematic Review and Meta-Analysis of Observational Studies.

Abstract

Systematic review and meta-analysis of observational studies. This systematic review and meta-analysis aimed to assess the possible relationship between atypical laterality curves and NAA. Idiopathic scoliosis (IS) is a three-dimensional spinal deformity of unknown origin. Some studies have shown a high prevalence of neural axis abnormalities (NAAs) in patients with IS, with possible differences in the prevalence of NAAs between curves with typical (right thoracic/left lumbar) or atypical laterality (the rest). This review protocol was previously registered in PROSPERO (CRD42024544809). A systematic search of the PubMed, Scopus, Web of Science, CINAHL and Scopus databases was performed through September 30, 2024. A total of 24 articles published between 1992 and 2021 involving 5379 subjects were included in the analysis. Twenty-four studies reported a prevalence of NAAs among patients with atypical laterality curves of 19.4% (95% CI 15.6 to 23.8) and 12.1% (95% CI 0.1 to 0.16) among those with typical laterality curves. Eleven studies estimated the prevalence of syringomyelia in patients with atypical laterality at 12.4% (95% CI 8 to 18.7) and that in patients with typical laterality at 6.1% (95% CI: 3.8 to 9.5). Eleven studies reported a prevalence of Arnold-Chiari syndrome in patients with atypical laterality of 12% (95% CI 6.9 to 20.1) and 7.7% (95% CI: 3.7 to 15.4) in those with typical laterality curves. Five studies reported a prevalence of tethered cord at 3.1% (95% CI 1.3 to 7.2; I²=0%) in patients with atypical laterality curves and a 2.1% (95% CI 0.5 to 8.8; I²=0%) prevalence among those with typical laterality. This study revealed that the prevalence of associated NAAs is greater among IS patients with atypical laterality curves, especially in patients with left dorsal curves and/or right lumbar curves. Syringomyelia is the most significant associated anomaly.