Os vesalianum pedis is an accessory bone of the foot located proximal to the fifth metatarsal and found within the peroneus brevis tendon. It is a rare occurrence [Incidence-0.1% and 0.4%]
The Os Vesalianum should be differentited in cases of fifth metatarsal avulsion fracture, ossifying apophysis of the fifth metatarsal base, Iselin’s disease, an ununited apophysis of the fifth metatarsal base and a fracture of the tuberosity of the fifth metatarsal, nonunion of a tuberosity fracture of the fifth metatarsal and an os peroneum.
Sometimes, os vesalianum may become symptomatic due to trauma and the treatment is rest, limited weight bearing, and/or casting. In cases resistant to conservative treatment, excision of the painful fragment, without disruption of the peroneus brevis tendon insertion can be done.