Examination of Morphometric Features of Accessory Bones in the Foot Using Computed Tomography

Accessory bones are generally considered to be developmental anomalies consisting of unfused ossification centers. These ossicles, which have no clearly defined function, can become infected and dislocated and can also be confused with avulsion fractures. In this study, we aimed to determine the morphometric characteristics and frequency of accessory bones in the foot. Foot computed tomography (CT) images (187 right, 213 left) of 400 individuals (239 men and 161 women) aged 18–86 years who underwent foot CT scans for various reasons were retrospectively reviewed. The surface area and the long and short diameters of the accessory bones were measured and recorded. Of the 400 ft, 270 (67.5%) had at least one accessory bone. The incidence was 57.6% in younger individuals, increasing to 81.4% in older individuals. 2.75% of accessory bones were bipartite. The most common were the accessory navicular bone (41.5%), os trigonum (14%) and os peroneum (13%). One accessory bone was identified that was not described in the available literature. Accessory bones have been proven to be quite common and may increase further in older age groups. The morphometric data obtained and the discovered accessory bone can contribute to the literature and guide clinicians in the diagnosis of related foot pathologies.