Type Ii Accessory Navicular Bone

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
Let us see the reasons why the tendon or the bone would get aggravated. Ankle or foot sprain, irritation of the bone caused by footwear, overusing the foot, quite common in athletes and dancers. People born with this extra bone are also known develop flat feet which also adds to the strain on the posterior tibial tendon and lead to the syndrome.

Symptoms
Symptoms of this syndrome would include redness, swelling and tenderness over the navicular bone. The navicular bone is located on the inside of the foot approximately midway between the ankle bone and big toe joint. It will tend to be worse after activity and can be aggravated by those that wear very dressy shoes as opposed to casual shoes like sneakers. In other words, the flatter or less supportive the shoe, the greater the chance for pain.

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
For less severe symptoms, decreasing or modifying activity, such as avoiding aggravating activities, may suffice. Ice and NSAIDS can be used to help control pain. An arch support or an orthotics may help to stabilize the arch during this time. When rubbing on the bump causes pain, a doughnut pad can be worn. Exercises to increase range of motion and improve movement should still be used.



Surgical Treatment
The above non-surgical options should be enough to treat accessory navicular syndrome. If they fail, a surgery would be necessary to remove the extra bone that has been causing the problems. The most common procedure for this condition is known as the Kidner procedure where a small incision is made over the navicular bone. The accessory navicular is identified and dissected free from the posterior tibial tendon. The posterior tibial tendon is then reattached to the remaining navicular bone.