The prevalence and anatomy of accessory navicular bone: a meta-analysis.

Purpose: There have been over 40 descriptions of the common developmental variants of the accessory ossicles of the feet. Although predominantly asymptomatic, they sometimes may be linked to painful conditions. One of the most common accessory ossicles in the foot is the accessory navicular bone (AN), located on the medial side of the foot. Our research provides a first meta-analysis on this topic that establishes its frequency by contrasting 39 studies from across the globe.

Methods: Up to February 2024, PubMed and Embase databases were thoroughly searched for research on the AN. Eligible data regarding AN prevalence was extracted. This study strictly adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines.

Results: A total of 39 studies, 11,015 patients, and 36,837 feet were analyzed in our study. The pooled prevalence estimate (PPE) of AN was found to be 17.5% (95%CI: 11.5-25.7) and 12.6% (95%CI: 10.1-15.5) in patients and feet analyses, respectively. Accessory navicular occurred bilaterally in 50.0% of patients, with similar distribution in gender-based groups (21.1% of males and 22.0% of females were confirmed with AN). Accessory navicular was most prevalent in the East Asian population (38.4%) and least prevalent in North Americans (8.0%). No significant differences in AN prevalence were found when comparing different imaging modalities (X-ray and cadaver dissection).

Conclusion: Accessory navicular is a common finding in imaging studies. Its prevalence depends on the population covered by the study but is not affected by the patient's gender or the imaging modality utilized for AN assessment.