Accessory Navicular: causes, symptoms and treatment

Why an Accessory Navicular Causes Problems

An accessory navicular may not cause problems in every patient. However, trauma to the foot can sometimes cause the accessory navicular to pull apart from the main bone, and when the two bones rub together, they can become inflamed.

Once the tiny bone is inflamed, it’s difficult to reduce the inflammation without medical intervention.

An accessory navicular can also be the source of flatfeet. The presence of an extra bone at the joining site of the posterior tibial tendon can weaken the tendon. Without the support of the tendon, the arch collapses.

The painful condition caused by an inflamed accessory navicular is called Accessory Navicular Syndrome. In addition to trauma, Accessory Navicular Syndrome can result from chronic irritation by ill-fitting shoes or from excessive activity and overuse.

Symptoms of Accessory Navicular Syndrome

Most people with accessory navicular syndrome start to notice symptoms in their teens when their youthful cartilage is developing into mature bone tissue. You or your adolescent may have Accessory Navicular Syndrome if you start to notice:

• A bony protrusion on the inside middle of the foot, just above the arch
• Swelling and redness around the protrusion
• Persistent or throbbing pain in the arch, especially during or after exercise

Diagnosing Accessory Navicular Syndrome

Make an appointment with your foot and ankle specialist if you believe you or your child are experiencing chronic foot pain. Your specialist will examine the shape of the foot, observe the foot’s mechanics while walking, and check for any abnormal bony prominences.

An X-ray is usually helpful in diagnosing Accessory Navicular Syndrome, and in some cases, an MRI or other imaging test may help to assess the severity of the condition.

Accessory Navicular Treatment Options

Some cases of Accessory Navicular Syndrome can be treated conservatively with nonsurgical treatments, such as:

Icing

Wrap a small bag of ice in a paper towel and apply it to the area for 15-20 minutes as needed to decrease pain and swelling.

Medication

Doctors recommend using nonsteroidal anti-inflammatory drugs (NSAIDs) to manage the pain and decrease inflammation. You can choose from several over-the-counter options that contain ibuprofen, such as Advil or Motrin.

Immobilization

Your specialist may set the foot in a cast or removable walking boot for 2-3 weeks to give the inflammation time to heal.

Physical therapy

Your specialist can show you how to perform daily exercises to strengthen the muscles, reducing pain, and helping to avoid future problems.

Orthotics

Your foot and ankle specialist can have you fitted for custom orthotic devices and inserts to provide arch support and reduce pain during physical activity.

Surgical Treatment: The Kidner Procedure

If conservative treatments are not enough to manage symptoms, then your foot and ankle specialist may recommend surgical intervention. The extra bone does nothing to help the foot’s mechanics, and so surgical removal could be an effective method for relieving pain and restoring proper foot function.

The Kidner procedure is a surgical technique that involves removing the accessory navicular bone and repositioning the posterior tibial tendon. The Kidner procedure is performed under general or spinal anesthesia. The surgeon makes an incision along the inner side of the foot just above the arch, which exposes the accessory bone and the posterior tibial tendon. The surgeon then removes the accessory navicular and reattaches the tendon to the main navicular bone.

The Kidner procedure is a relatively low-risk surgery with a high chance of normal functioning after recovery. The patient can expect to be resting in bed in a surgical cast for about 2-3 weeks and then working their way up to weight-bearing in a boot for 2-4 additional weeks. After 6 weeks, most patients can bear their full weight on the foot and start physical therapy, returning to their normal foot function after about 6 months of rehabilitation.

UFAI, the Best Pediatric Podiatrists

The child podiatrists at University Foot and Ankle Institute are nationally recognized for their treatment and care of our pediatric foot and ankle patients. They are committed to getting your child back to doing what they love in using the least invasive treatment possible.