Large Accessory Navicular Bone

Overview
This syndrome is also referred to as os tibial naviculare or os tibial externum. As stated above, this condition quite often does not cause any pain. But if the posterior tibial tendon (the extra bone attaches to this tendon in the foot) or the accessory navicular bone itself were to get aggravated, then there would be pain.



Causes
People who have an accessory navicular often are unaware of the condition if it causes no problems. However, some people with this extra bone develop a painful condition known as accessory navicular syndrome when the bone and/or posterior tibial tendon are aggravated. This can result from any of the following. Trauma, as in a foot or ankle sprain. Chronic irritation from shoes or other footwear rubbing against the extra bone. Excessive activity or overuse.

Symptoms
Symptoms of accessory navicular syndrome often appear in adolescence, when bones are maturing. Symptoms include A visible bony prominence on the midfoot, Redness and swelling, Vague pain or throbbing in the arch, especially after physical activity.

Diagnosis
To diagnose accessory navicular syndrome, medical staff ask about the patient?s activities and symptoms. They will examine the foot for irritation or swelling. Medical staff evaluate the bone structure, muscle, joint motion, and the patient?s gait. X-rays can usually confirm the diagnosis. MRI or other imaging tests may be used to determine any irritation or damage to soft-tissue structures such as tendons or ligaments. Because navicular accessory bone irritation can lead to bunions, heel spurs and plantar fasciitis, it?s important to seek treatment.

Non Surgical Treatment
Fortunately, surgery is not the only answer when it comes to relieving symptoms of accessory navicular syndrome. The physician may recommend wearing a cast or walking boot for a period of time so the foot can recover from the inflammation. Ice may be used to relieve swelling, too, although it should be wrapped to avoid direct contact with the skin.



Surgical Treatment
If conservative care does not alleviate the problem then surgical intervention should be considered. The most common procedure for this condition is known as the Kidner procedure where a small incision is made over the navicular bone. The accessory navicular is identified and dissected free from the posterior tibial tendon. The posterior tibial tendon is then reattached to the remaining navicular bone.