The navicular bone is located on the inside of the foot just above the arch. One in 10 people has an accessory navicular bone, which is an extra piece of bone attached to the navicular. Just like other bones, the accessory navicular bone grows and hardens in adolescence. People with an accessory navicular may experience pain and swelling from shoe pressure or from frequent sprains where the extra piece of bone attaches.
Many people with an accessory navicular do not experience symptoms, however, some may notice a bump and/or swelling on the inside of the foot just above the arch. They may also experience pain in the middle of the foot, particularly with physical activity.
Your doctor will diagnose an accessory navicular by examining your child’s foot. Your physician may also obtain x-rays to confirm the accessory navicular and to rule out other conditions.
Most children’s symptoms are improved or resolved by taking a break from activities that irritate their feet. Shoe inserts that pad the accessory navicular area are also helpful.
If your child’s symptoms do not improve, your physician may recommend a below-the-knee cast or walking boot. Surgery is rarely needed.