Will Accessory Navicular Syndrome Always Need Surgery

Overview
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. Many people with accessory navicular syndrome also have flat feet (fallen arches). Having a flat foot puts more strain on the posterior tibial tendon, which can produce inflammation or irritation of the accessory navicular.



Causes
The syndrome may result from any of the following, previous trauma such as a foot or ankle sprain. Chronic irritation from shoes or other footwear causing friction against the bone. Strain from overuse or excessive activity.

Symptoms
Symptoms of this syndrome would include redness, swelling and tenderness over the navicular bone. The navicular bone is located on the inside of the foot approximately midway between the ankle bone and big toe joint. It will tend to be worse after activity and can be aggravated by those that wear very dressy shoes as opposed to casual shoes like sneakers. In other words, the flatter or less supportive the shoe, the greater the chance for pain.

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
Treatment of the accessory navicular begins with rest, which may include activity modification or temporary immobilization in a boot or a brace. Once the inflammation subsides the foot needs to be supported. The support consists of a specially designed orthotic arch support. Occasionally, the orthotic will dig into the edge of the accessory navicular bone under the arch of the foot. This is very uncomfortable. For this reason the orthotic support needs to be carefully made. The orthotic support will help control (but not cure) the flat foot and will often decrease the inflammation on the navicular.



Surgical Treatment
Depending upon the severity the non operative or conservative treatment should be maintained for at least 4- 6 months before any surgical intervention. There are 2 surgeries that can be performed depending upon the condition and symptoms. First is simple surgical excision. In this generally the accessory navicular along with its prominence is removed. In this procedure, skin incision is made dorsally to the prominence of accessory navicular. Bone is removed to the point where the medial foot has no bony prominence over the navicular, between the head of the talus and first cuneiform. Symptoms are relieved in 90% of cases. Second is Kindler procedure. In this the ossicle and navicular prominence is excised as in simple excision but along with the posterior tibial tendon advancement. Posterior tibial tendon is split and advanced along the medial side of foot to provide support to longitudinal arch. After surgery 4 week short leg cast, well moulded into the arch with the foot plantigrade is applied. Partial weight bearing till the 8th week and later full weight bearing is allowed. When the cast is being removed can start building up the ROM to counter atrophy and other physical therapy treatment which include stretching and strengthening exercises.