What Is Accessory Navicular Syndrome

Overview
The accessory navicular is an extra piece of cartilage or bone on the inner side of the foot. It is found in about 10 percent of individuals and is present at birth. Many people who have an accessory navicular are never aware of it because they do not experience symptoms. However, aggravation of the accessory navicular or the posterior tibia tendon, which it is attached to, can develop as a result of trauma, irritation from shoes, and excessive overuse.



Causes
Accessory navicular syndrome as it is called can result from a number of causes, excess or overuse syndrome as seen in an athlete. Trauma to the foot as in an ankle sprain or direct trauma to the navicular bone. chronic irritation from shoes rubbing against the extra bone, over time, may cause pain. Excessive pronation which strains the attachment of tibialis posterior muscles into the navicular bone. Keep in mind, the larger the actual accessory bone, the greater the chance of it becoming an issue.

Symptoms
The majority of people with an accessory navicular experience no symptoms, since, for the most part, the little extra bone simply isn?t large enough to cause problems. Unfortunately, some people lose on ?accessory navicular roulette,? and the bone begins to mess things up with the foot. These problems usually show up sometime in adolescence, when bones and cartilage in the body are settling into their final shapes (although occasionally people make it all the way through childhood, only to start experiencing discomfort and pain in adulthood).

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
The treatment for a symptomatic accessory navicular can be divided into nonsurgical treatment and surgical treatment. In the vast majority of cases, treatment usually begins with nonsurgical measures such as orthotics, strappings or bracing. Surgery usually is only considered when all nonsurgical measures have failed to control your problem and the pain becomes intolerable.



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.