RESUMO
BACKGROUND: Os peroneum and os vesalianum are sesamoid bones that could be found within fibularis longus and brevis tendons, respectively. They are rarely a cause of lateral foot pain and are often identified as incidental radiographic findings. However, in the context of trauma, these sesamoids may be radiographically misinterpreted as fractures. This study aimed to evaluate the prevalence and normal morphological variants of os peroneum and os vesalianum. MATERIALS AND METHODS: Standard oblique lateral and/or anteroposterior radiographic views of 624 feet of adolescent and adult patients were retrospectively reviewed to determine the prevalence and anatomical variations of the os peroneum and os vesalianum in relation to age and gender using plain radiography. RESULTS: Os peroneum was found in 22% and os vesalianum was found in 1.6%. Age was found to significantly correlate with the presence of os peroneum with the highest prevalence (30%) detected in the elderly group. Among 137 feet with os peroneum, 54.0% were between 4 and 8 mm, 67.2% were close to the tubercle of cuboid, 32.8% were located at the level of calcaneocuboid joint, 81.8% were solitary, and 18.2% were bi-/multipartite. Among 10 feet with os vesalianum, type I was identified in 40% and type II in 60%. CONCLUSIONS: Different anatomical variants of the lateral sesamoid bones of the foot have been described in this study. A thorough knowledge of normal anatomical variants is essential for proper diagnosis and management and can enhance our diagnostic skills in detecting these sesamoids.