Os subfibulare. Investigation of an accessory bone

During dissection of a cadaver at the Ohio College of Podiatric Medicine, the authors encountered the os subfibulare. The os subfibulare was encased within the peroneus longus and peroneus brevis tendons and initially appeared as though it may have articulated with the left lateral malleolus distally and posteriorly. The ossicle was not associated with any capsular or ligamentous structures. These findings suggest that the os subfibulare is a true sesamoid bone. A review of the literature is presented and the clinical significance of these findings is discussed.