Exercises For Accessory Navicular Syndrome

Overview
The accessory navicular (os navicularum or os tibiale externum) is an extra bone or piece of cartilage located on the inner side of the foot just above the arch. It is incorporated within the posterior tibial tendon, which attaches in this area. An accessory navicular is congenital (present at birth). It is not part of normal bone structure and therefore is not present in most people. People who have an accessory navicular often are unaware of the condition if it causes no problems. However, some people with this extra bone develop a painful condition known as accessory navicular syndrome when the bone and/or posterior tibial tendon are aggravated. This can result from any of the following. Trauma, as in a foot or ankle sprain. Chronic irritation from shoes or other footwear rubbing against the extra bone. Excessive activity or overuse. Many people with accessory navicular syndrome also have flat feet (fallen arches). Having a flat foot puts more strain on the posterior tibial tendon, which can produce inflammation or irritation of the accessory navicular.



Causes
This painful foot condition is caused by an extra bone in the foot called the accessory navicular. Only about 10% of people have this bone (4 to 21%), and not all of them will develop any symptoms. The navicular bone is one of the normal tarsal bones of the foot. It is located on the inside of the foot, at the arch.

Symptoms
Possible symptoms of accessory navicular syndrome include redness or swelling in the area of the accessory navicular, and pain that is present around the middle of the foot around the arch. Discomfort is most often present following periods of exercise or prolonged walking or standing. The bone may be somewhat visible on the inside of the foot above the arch. Most symptoms of accessory navicular syndrome first appear in childhood around the time of adolescence as the bones are still growing and developing. For some with an accessory navicular, though, symptoms may not appear until entering adulthood.

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
A combination of the following non-surgical treatments may be used to relieve the symptoms of accessory navicular syndrome. Immobilizing the foot with a cast or a removable walking boot allows the foot to rest and reduces inflammation. Applying ice to the affected area is an effective way to reduce swelling and inflammation. Wrap a bag of ice with a thin towel and apply for intervals of 15 to 20 minutes. Never put ice directly on the skin. Oral nonsteroidal anti-inflammatory drugs (NSAIDs) including aspirin or ibuprofen might be prescribed. Sometimes, a combination of immobilization and oral or injected corticosteroid medications may reduce pain and inflammation. Physical therapy may be prescribed to include exercises and treatments that increase muscle strength, decrease inflammation and help prevent the recurrence of symptoms. Custom orthotic devices worn in the shoe provide arch support and may prevent future symptoms from developing. The symptoms of this syndrome may reappear even after successful treatment. If so, non-surgical treatments are often repeated.



Surgical Treatment
The Kidner procedure involves resecting the prominent accessory navicular and ensuring that the posterior tibial tendon is still attached to the bone. Often the prominent bone can simply be shelled out from its position relative to the posterior tibial tendon, which leaves the tendon intact. However, if the tendon is loose and floppy once the extra bone has been removed, suturing or tother is required as a means of attaching it into the remaining navicular bone.