Physical Therapy Exercises For Accessory Navicular Syndrome

Overview
Some people have more bones in their feet than others. Actually, it?s not all that uncommon to have extra bones in the feet. These extra bones area called accessory bones. The navicular bone, one of the small bones located at the instep or arch of the middle of the foot, is an example of an extra bone people are born with. It?s called the accessory navicular bone. During the maturation process, the navicular and the accessory navicular never fuse into one solid bone, but remain connected by fibrous tissue or cartilage. It is estimated that 4-14% of the population are born with an accessory navicular bone.



Causes
An injury to the fibrous tissue connecting the two bones can cause something similar to a fracture. The injury allows movement to occur between the navicular and the accessory bone and is thought to be the cause of pain. The fibrous tissue is prone to poor healing and may continue to cause pain. Because the posterior tibial tendon attaches to the accessory navicular, it constantly pulls on the bone, creating even more motion between the fragments with each step.

Symptoms
The main symptom of an aggravated accessory navicular is pain, particularly in the instep. Walking can sometimes be difficult, and tight shoes may worsen the condition.

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
Initial treatment is conservative. With the first episode of symptoms, a medial heel wedge, anti-inflammatories, and physical therapy can be helpful. If very painful, a cast or boot may be needed for a short period time before the wedge and physical therapy can be initiated. Very rarely is a steroid injection warranted or recommended. As the pain improves, patients can resume activities. For a minority of patients, an arch support or custom orthotic can help to take some of the extra pressure off of the accessory navicular and the posterior tibial tendon.



Surgical Treatment
After the anesthesia is administered you will be heavily sedated and placed on your stomach. Surgeons will place a tourniquet around your thigh and an incision will be made on the inside of the foot. The posterior tibial tendon will be moved as necessary and the accessory navicular will be removed. Surgeons will repair the posterior tibial tendon with sutures or suture anchors, and the wound will be closed. A splint will be placed on the foot for stabilization and immobilization. You will be permitted to leave the surgical center once you have been cleared by the anesthesiologist. Plan ahead to have a friend or family member take your prescription to a pharmacy to pick up your post-op medication. Use narcotic pain medications before bed or if numbness in your foot begins to dull. Schedule a post-op visit for 4 weeks after the procedure.