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.
It is commonly believed that the posterior tibial tendon loses its vector of pull to heighten the arch. As the posterior muscle contracts, the tendon is no longer pulling straight up on the navicular but must course around the prominence of bone and first pull medially before pulling upward. In addition, the enlarged bones may irritate and damage the insertional area of the posterior tibial tendon, making it less functional. Therefore, the presence of the accessory navicular bone does contribute to posterior tibial dysfunction.
The primary reason an accessory navicular becomes a problem is pain. There is no need to do anything with an accessory navicular that is not causing pain. The pain is usually at the instep area and can be pinpointed over the small bump in the instep. Walking How can we increase our height? be painful when the problem is aggravated. As stated earlier, the condition is more common in girls. The problem commonly becomes symptomatic in the teenage years.
The foot and ankle are prone to bony ?accessories? which usually have no accompanying symptoms. Accessory navicular syndrome is often diagnosed when an adolescent complains of pain in the foot. Girls are more susceptible than boys, and the condition is usually bilateral, occurring in both feet. Navicular accessory syndrome may be diagnosed when a trauma (foot or ankle sprain) aggravates the bone or tibial tendon, or when there is chronic irritation from footwear or overuse.
Non Surgical Treatment
The initial treatment approach for accessory navicular is non-operative. An orthotic may be recommended or the patient may undergo a brief period of casting to rest the foot. For chronic pain, however, the orthopedic surgeon removes the extra bone, a relatively simple surgery with a brief rehabilitation period and a very good success rate.
If all nonsurgical measures fail and the fragment continues to be painful, surgery may be recommended. The most common procedure used to treat the symptomatic accessory navicular is the Kidner procedure. A small incision is made in the instep of the foot over the accessory navicular. The accessory navicular is then detached from the posterior tibial tendon and removed from the foot. The posterior tibial tendon is reattached to the remaining normal navicular. Following the procedure, the skin incision is closed with stitches, and a bulky bandage and splint are applied to the foot and ankle. You may need to use crutches for several days after surgery. Your stitches will be removed in 10 to 14 days (unless they are the absorbable type, which will not need to be taken out). You should be safe to be released to full activity in about six weeks.