Global, regional, and national burden of congenital musculoskeletal and limb anomalies, 1990-2021: a systematic analysis of the global burden of disease in 2021.

Abstract

Background: Congenital musculoskeletal and limb (CML) anomalies are uncommon, multifactorial conditions whose global incidence trends remain underexplored. This study delineates the epidemiology and temporal evolution of CML anomalies from 1990 to 2021.

Methods: We extracted data from the 2021 global burden of disease (GBD) Study, stratifying by sex, region, country and socio-demographic index (SDI). We calculated age-standardized incidence rate (ASIR), age-standardized mortality rate (ASMR), age-standardized prevalence rate (ASPR), and estimated annual percentage change (EAPC). Decomposition analysis quantified the contributions of population growth, aging, and epidemiological change. Projections to 2031 were made using an autoregressive integrated moving average (ARIMA) model. Health inequities were assessed via the slope index of inequality (SII) and concentration index (CI).

Results: Global epidemiological patterns of CML anomalies exhibited significant disparities between 1990 and 2021. Brunei Darussalam demonstrated the highest ASIR, while Afghanistan and the United Mexican States recorded the highest ASMR and ASPR, respectively. Absolute case and death burdens predominantly clustered in populous nations, with India and China reporting the highest absolute numbers. ARIMA modeling projected a 0.85% increase in incident cases (from 2,437,890.12 to 2,458,596.45), a 25.46% decrease in mortality (from 13,599.83 to 10,137.02), and a 3.55% increase in prevalence (from 18,549,408.27 to 19,207,414.19) by 2031. Decomposition analyses revealed that population growth was the primary driver of increased cases in middle SDI regions, whereas epidemiological transitions and aging were the main contributors to mortality reductions. In lower-middle SDI regions, concurrent demographic expansion and epidemiological changes amplified case burdens. Health inequality significantly increased, with the incidence CI rising from 0.28 to 0.35 and the mortality CI from 0.34 to 0.42 between 1990 and 2021. Significant correlations were observed between EAPC and baseline ASIR/ASMR, with declining trends in mortality and rising prevalence driven by population growth and epidemiological transitions.

Conclusion: From 1990 to 2021, CML anomalies' incidence and mortality exhibited divergent trends across SDI strata, with less favorable outcomes in lower-SDI countries. Tailored interventions are essential to mitigate the growing burden in these settings.