Accessory navicular describes the presence of an extra bone growth center on the inside of the navicular and within the posterial tibial tendon that attaches to the navicular. The primary symptom from this additional bony prominence is pain and tenderness. This congenital defect (present at birth) is thought to occur during development when the bone is calcifying. Because this accessory portion of the bone and the navicular never quite grow together, it is believed that, over time, the excessive motion between the two bones results in pain.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 accessory navicular syndrome often appear in adolescence, when bones are maturing. Symptoms include A visible bony prominence on the midfoot, Redness and swelling, Vague pain or throbbing in the arch, especially after physical activity.Diagnosis
Usually, you will only need an X-ray to determine the size or type of the accessory navicular bone or the amount of medial navicular tuberosity hypertrophy. Be cognizant of stress fractures which may be duplicated as a hairline fracture or increased calcification. When treating children, always look for avascular necrosis of the navicular (Kohler?s disease). An X-ray of this condition will reveal a flattening of the navicular along with increased bone density.Non Surgical Treatment
In order to strengthen your muscles to prevent further injury and to provide support to the foot, your podiatrist may also outline a physical therapy routine and prescribe orthotics. Orthotics will provide support to the arch of your foot, although they must be carefully crafted in order to make room for that pesky extra bone you?ve got poking about.Surgical Treatment
In my experience, the Modified Kidner procedure is one of the most reliable operations for reducing arch pain associated with an accessory navicular bone (a.k.a. os tibial externum). Do you get taller when you stretch?
can also use this procedure to treat a prominence at the inner aspect of the arch, which has been caused by an enlarged navicular bone. The most common patients to visit our office with these problems are between the ages of 8 and 15 and are involved in activities like ice skating, ballet and soccer.