The fibularis brevis muscle typically inserts by a single long, robust, flat tendon upon the base of the fifth metatarsal. In this case report, we demonstrate two comparatively small accessory tendons of insertion in both the right and left limbs of an elderly cadaver. In each limb, the superior and inferior accessory tendons arose from the distal end of the main tendon of insertion to attach to, respectively, the shaft and neck of the fifth metatarsal. The bilateral presence of this comparatively rare condition is a new finding. Review of the literature reveals that these accessory tendons are most probably remnants of the inserting tendons of the atavistic muscle peroneus digiti minimi. The presence of this anomaly could affect reconstruction surgeries that utilize the inserting tendon of fibularis brevis, and treatment of avulsion fractures of the base of the fifth metatarsal.
KEY WORDS: Fibularis brevis muscle; Peroneus brevis muscle; Insertion; Tendon; Anomaly.