Epidemiology and clinical significance of os subtibiale in European and Asian populations: a meta-analysis with treatment, diagnosis, and management considerations

Abstract

Background: The os subtibiale (OS) is a rare accessory ossicle located near the medial malleolus. Epidemiological knowledge of this anatomical variation is limited and has not yet been fully explored.

Objective: The aim of this study was to systematically summarize all available data regarding the prevalence of the OS, establish sex- and geography-related epidemiological patterns, and discuss its role in clinical practice.

Methods: Pubmed/MEDLINE, Embase, and ScienceDirect were thoroughly searched up until August, 2025, for articles presenting original data on the OS. The protocol of the study had been pre-registered in PROSPERO (ID: CRD420251164899), adhered to PRISMA guidelines, and used AQUA tool to evaluate study risk of bias. A random-effect model meta-analysis was used to calculate pooled prevalence estimates (PPEs), where between-study heterogeneity was measured with the I² statistic, and Chi² test. Doi plots and LFK index have been used to assess the publication bias.

Results: A total of 14 studies (16 082 feet) were included in our study. The PPE of the OS in the general population was 0.51% (95%CI: 0.27%–0.82%, I² = 81.46, P <0.001), where the LFK index of -0.98 revealed low potential for publication bias. In females the PPE of the OS was 0.30% (95%CI: 0.08%–1.05%; I² = 38.78; P = 0.195), whereas in males - 0.57% (95%CI: 0.18%–1.82%; I² = 72.09; P = 0.028). The prevalence of the ossicle was considerably higher in Europe (PPE = 0.97%, 95%CI: 0.48%–1.90%; I² = 71.27; P = 0.008) than in Asia (PPE = 0.49%, 95%CI: 0.30%–0.81%; I² = 56.05; P = 0.026).

Conclusions: Our study showed that the OS is a rare anatomical variation present in 1 in 200 feet. Proper identification of the OS is essential to avoid unnecessary treatment and ensure appropriate clinical management.