Are patient demographics different for early-onset and late-onset Blount disease? Results based on meta-analysis.

Early-onset and late-onset Blount disease has been described with some clinical overlap between the two forms. Using PRISMA guidelines, we searched for articles that included demographics of patients with both types of Blount disease. On the basis of 24 articles that met our inclusion criteria, patients with early-onset Blount disease were more likely to have bilateral involvement [odds ratio (OR) 4.30, 95% confidence interval (CI) 2.27-8.17] and less likely to be Black (OR 0.20, 95% CI 0.08-0.53) or male (OR 0.32, 95% CI 0.13-0.78). Our results confirm that differences based on laterality, race, and sex exist between the two forms of Blount disease.