Have I Got Accessory Navicular Syndrome

Overview
An accessory navicular is an extra bone that is on the inner center arch of the foot. Up to 2.5% of individuals are born with the accessory navicular. Throughout early childhood, this condition is not noticed. However, in adolescence, when the accessory navicular begins to calcify, the bump on the inner aspect of the arch becomes noticed. For most, it is never symptomatic. However, for some, there is some type of injury, whether a twist, stumble, or fall, that makes the accessory navicular symptomatic.



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
What precipitates the pain? It will usually be caused by rubbing of the skate or other footwear against the prominence. You?ll commonly see blisters or a red irritated area. Other symptoms to look for, especially when you?re treating an older child or adult, include an area of pain along the posterior tibial tendon of the arch and fatigue of the legs. Typically, these patients are not able to participate in sports for a lengthy period of time or you?ll hear them complain of pain and/or soreness after extended activities. Most individuals with a prominent navicular area will have tried accommodating this area with a doughnut pad or adjustments to their skate.

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
If the foot becomes painful following a twisting type of injury and an X-ray reveals the presence of an accessory navicular bone, your doctor may recommend a period of immobilization in a cast or splint. This will rest the foot and perhaps allow the disruption between the navicular and accessory navicular to heal. Your doctor may prescribe anti-inflammatory medication. Sometimes an arch support can relieve the stress on the fragment and decrease the symptoms. If the pain subsides and the fragment becomes asymptomatic, further treatment may not be necessary.



Surgical Treatment
If non-operative treatment fails to relieve the patient’s symptoms, surgical intervention may be warranted. The standard operative treatment of an accessory navicular is a Kidner procedure. However, if surgery is undertaken it is important that it address the underlying source of the patients pain.