Will Accessory Navicular Syndrome Require Surgery

Overview
When there is injury to the muscle, fibrous tissue, or soft tissue of the navicular and the accessory navicular bones, symptoms will arise. This injury allows excessive movement between the bones. Fibrous tissue, ligaments and tendons have poor blood supply and are prone to poor healing. Often, this extra navicular bone lies near or attaches to the posterior tibial tendon. (See figure.) When the posterior tibial muscle contracts with movements such as foot inversion or plantar flexion, the posterior tendon moves and the accessory navicular bone moves. This can cause severe pain in those with Accessory Navicular Syndrome. It can become disabling to patients because the posterior tibial tendon attached to the navicular bone is responsible for supporting the medial arch during standing, walking and running. Activities which most of us do daily!



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
If you develop accessory navicular syndrome, you may experience a throbbing sensation or other types of pain in your midfoot or arch (especially while or right after you use the foot heavily, such as during exercise), and you may notice a bony prominence on the interior of your foot above the arch. This prominence may become inflamed, which means it will likely feel warm to the touch, look red and swollen, and will probably hurt.

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
Most cases of accessory navicular syndrome may be treated conservatively with some sort of immobilization. This should allow the fibrous tissue between the two bones to heal. If a patient is extremely flat footed (pronated) then I lean more towards an orthotic than a boot as my main goal is to keep the patient's foot from flattening out too much and thus reduce the strain on the two bones. Supplementation with ice, oral anti-inflammatory medication. If the patient is athletic sometimes we can keep them active with an orthotic, but other times they have to give up their sport for a period of time to allow the condition to heal.



Surgical Treatment
If all nonsurgical measures fail and the fragment continues to be painful, surgery may be recommended. The most common procedure used to treat the symptomatic accessory navicular is the Kidner procedure. A small incision is made in the instep of the foot over the accessory navicular. The accessory navicular is then detached from the posterior tibial tendon and removed from the foot. The posterior tibial tendon is reattached to the remaining normal navicular. Following the procedure, the skin incision is closed with stitches, and a bulky bandage and splint are applied to the foot and ankle. You may need to use crutches for several days after surgery. Your stitches will be removed in 10 to 14 days (unless they are the absorbable type, which will not need to be taken out). You should be safe to be released to full activity in about six weeks.