National and regional trends in the prevalence of adolescent idiopathic scoliosis in South Korean military draftees.

Introduction: Recent epidemiological and aetiological data on adolescent idiopathic scoliosis (AIS) among military draftees are scarce in nationwide and population-based databases. This retrospective, nationwide and population-based study aims to assess national and regional trends in the prevalence of AIS among military draftees in South Korea from 2013 to 2022.

Methods: A total of 3 166 669 Korean males were screened at regional Military Manpower Administration (MMA) offices between 2013 and 2022. Based on routine chest radiographs, individuals with Cobb's angle of ≥10° were screened and diagnosed with AIS using whole spine radiographs after excluding surgically treated AIS patients. Data from the MMA were retrospectively collected and the annual prevalence of the total and neglected AIS cases, along with 95% CIs, was assessed. Spearman correlation analysis was performed to evaluate the correlation between the prevalence of AIS and several aetiological factors.

Results: The prevalence rate of AIS in the male adolescent population gradually increased from 2013 (0.44%, 95% CI 0.42% to 0.46%) to 2022 (1.33%, 95% CI 1.28% to 1.37%). The AIS rate increased overall in both capital/metropolitan areas and provinces but showed a fluctuating pattern in the capital/metropolitan area. The prevalence rate of neglected AIS showed a very slight increased trend during the same period (mean 0.05%, 95% CI 0.04% to 0.06%) and exhibited a similar pattern in both capital/metropolitan areas and provinces. Using correlation analysis with aetiological factors, the prevalence rate of AIS correlated with overweight or obesity rate (r=0.90, p<0.001) and growth hormone use (r=0.83, p<0.001).

Conclusions: The prevalence of AIS in the male population has increased, with a similar trend observed between capital/metropolitan areas and provinces in South Korea. Our correlation results support both the multifactorial cascade concepts for altered body composition effects and biomechanical progression based on the Hueter-Volkmann effect as the pathomechanisms of AIS.