Type Ii Accessory Navicular Bone

Overview
Some people, possibly beginning in early adolescents, but perhaps later, can develop a painful bump on the side of their foot. The pain may be worse after athletic activity or just normal walking, and walking itself may become painful. This pain may become constant, but it will tend to improve with continued rest. Depending on the size of the bump, it may rub against shoes, or cause pain if the bump is hit by something. Over time, the arch of the foot may be lost and a flat food will develop.



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
A visible bony lump on the inner part of the foot, towards the middle, just above the arch of the foot. Redness, swelling, and sensitivity of the bony prominence. Pain or throbbing in the middle of the foot and the arch. Difficulty with foot movement and activity. Possible skin callous or skin irritation caused by footwear rubbing over the lump. Not everyone who has an accessory navicular will develop these problems. When problems do occur, they may begin in early adolescence. The obvious indication is a painful bump on the inside of the foot, which hurts to touch, and causes problems that gradually become worse, and which are aggravated by activity, walking, etc., leading to all the problems discussed here. Pain may be worse towards the end of the day, and continue into the night.

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 foot may be placed in a cast or removable walking boot to allow the affected area to rest and decrease the inflammation. Physical therapy including exercises and treatments to strengthen the muscles, decrease inflammation, and prevent recurrence of the symptoms. Custom orthopedic devices that fit into the shoe providing arch support. Even after successful treatment, symptoms may reappear.



Surgical Treatment
In the original Kidner procedure, the entire posterior tibial tendon was released from the navicular and then rerouted through a drill hole placed through the navicular. The original Kidner procedure is now rarely used as a means of treating an isolated accessory navicular. Instead, a modification of the Kidner procedure has become more commonplace. The modified Kidner procedure consists of carefully removing the accessory and anchoring the posterior tibial tendon to the surface of the navicular where the accessory was removed. The repair may be done by passing a suture through the tendon and then through drill holes in the navicular, or by using a suture anchor.