The prevalence of varus thrust: A systematic review and meta-analysis

To determine the prevalence of varus thrust in adults with and without knee osteoarthritis (OA), including across clinically relevant subgroups. A secondary objective was to explore whether varus thrust prevalence varied according to age, body mass index (BMI), and knee pain severity, where sufficient data were available. A systematic review was conducted in accordance with PRISMA guidelines. Five electronic databases and Google Scholar were searched from inception to January 21, 2025. Studies reporting varus thrust during gait in adults, assessed using clinical observation methods, were included. Two independent reviewers screened studies, extracted data, and assessed methodological quality. Overall, 16 studies were included. Among people with knee OA, varus thrust was prevalent in 20.6% of knees (95% CI: 15.4%-27.0%) and 26.9% of individuals (95% CI: 21.6%-32.9%). Only two studies included adults without knee OA or self-reported healthy populations. Therefore, meta-analysis for this group was not possible. In people with knee OA, varus thrust prevalence was 34.9% in those with varus alignment (95% CI: 27.6%-43.0%) and increased with greater radiographic OA severity, reaching 54.3% in those with K/L grade 4. Pooled prevalence was numerically higher in males than in females, but the between-subgroup difference was not statistically significant. Varus thrust is prevalent in clinically studied knee OA cohorts, particularly in people with varus alignment and more severe radiographic OA. Evidence in adults without knee OA remains limited, and broader population-based prevalence across the OA spectrum is still insufficiently characterised.