Preliminary Results of the Prevalence of Scoliotic Curves and Gender Distribution in Adolescent Idiopathic Scoliosis: Meta-Analysis of Untransformed Proportions.

OBJECTIVES

This study provides a pooled estimate of the prevalence of spinal curve patterns and gender distribution in Adolescent Idiopathic Scoliosis. The goal is to establish a clinical baseline to optimize screening and surgical planning.

METHODS

A preliminary systematic search of PubMed, Scopus, WOS, and Cochrane Library identified 24 studies (n=2,793). Meta-analysis used the Inverse Variance method with a Restricted Maximum-Likelihood (REML) random-effects model. Statistical analysis was performed using R software version 4.3.2. Proportions were analyzed as untransformed values to maintain data integrity.

RESULTS

Among Single Curve Patterns, the pooled prevalence was: Thoracic 41.09% (n=2,713), Thoracolumbar 33.70% (n=2,689), and Lumbar 22.03% (n=2,305). For Multiple/Complex Patterns, Double Major curves accounted for 30.26% (n=666) and Triple curves 7.44% (n=472). Gender analysis revealed a Female prevalence of 79.07% and a Male prevalence of 20.93% (ratio ∼4:1). The cumulative prevalence exceeds 100% due to the independent meta-analytical modeling of each pattern, reflecting clinical overlaps where complex curves involve multiple regions.

CONCLUSIONS

Thoracic and thoracolumbar patterns are the most frequent manifestations of AIS, with a consistent 4:1 female predominance. The overlapping prevalences underscore the complexity of classification and the urgent need for standardized reporting criteria to harmonize global epidemiological data.