I am 13-years-old and need some advice. My best friend just got cut from the dance team because she has an extra bone in her foot that is causing terrible pain. She says the doctor told her this is a common problem but usually the person doesn’t know it unless dancing or doing some other athletic activity. How can I tell if I have it too?

Many people are born with oddly shaped bones, extra bones, or fused bones and never know about it. In fact, studies show up to one-third of the general population have what is called an accessory (extra) bone. Sometimes these extra bones are in the joint and sometimes they occur embedded in a tendon or muscle.

Most of the time, unless the bone is prominent, no one knows about them. But dancers and other athletes are often the first to notice problems. The strain and stress on the feet from repetitive movements, wearing special (toe) shoes (dancers), and the positions assumed (up on toes, feet turned out) can cause tenderness and pain in the foot and/or ankle.

Usually the condition is suggested by the history and the tenderness over the area of the navicular. The only way to know for sure if you have this type of anomaly is an X-ray. Generally no other tests are required.

Just having an accessory navicular bone is not necessarily a bad thing. Not all people with these accessory bones have symptoms. Symptoms arise when the accessory navicular is overly large or when an injury disrupts the fibrous tissue between the navicular and the accessory navicular. A very large accessory navicular can cause a bump on the instep that rubs on your shoe causing pain. If you are not experiencing this type of pain and there is no bump on the instep of your foot, there’s no need to worry or get X-rays.