Sometimes if the tendon that inserts in the base of the 5th metatarsal or wraps around the cuboid bone can have another bone nearby. This is called an accessory bone or ossicle. Sometimes it can be near the bone and dislodged with a sprain of the foot.
You can see the fracture of the bone here. In order to make the diagnosis we need to have an MRI as my patient was not as clear as this. Do you see the peroneal groove that is where the peroneus longus tendon runs.
Here are some helpful websites to learn more about this condition:
- http://www.ajronline.org/content/177/1/257.2 - This is a very technical article for those that want to learn more.
- http://emedicine.medscape.com/article/1236405-treatment#a1128 - This is a nice reference article on os peroneum and peroneal tendon injuries
To your health,
Dr. Donald Pelto