Os Navicular Syndrome: A Symptomatic Accessory Ossicle of the Foot

Accessory navicular bone occurs due to failure of fusion of a secondary ossification center with the navicular. It is the second most common ossicle of the foot, with majority of them being identified incidentally on imaging studies. We report a case of 45-year-old female who presented with complaints of pain and localized redness over the medial aspect of the right foot which was aggravated on walking. This brief review aims to describe the pathophysiology, radiographic findings and management of Os naviculare syndrome. We also wish to highlight to the physicians that it must be suspected in patients with localized pain over the medial aspect of the midfoot without obvious trauma. The presence of accessory navicular should not be disregarded as an incidental radiological variant in a symptomatic patient.