Can Accessory Navicular Syndrome Be Uncomfortable

Overview
The navicular bone is located on the inside of the foot just above the arch. One in 10 people has an accessory navicular bone, which is an extra piece of bone attached to the navicular. Just like other bones, the accessory navicular bone grows and hardens in adolescence. People with an accessory navicular may experience pain and swelling from shoe pressure or from frequent sprains where the extra piece of bone attaches.



Causes
Most of the time, this condition is asymptomatic and people may live their whole lives unaware that they even have this extra bone. The main reason the accessory navicular bone becomes problematic is when pain occurs. There is no need for intervention if there is no pain. The accessory navicular bone is easily felt in the medial arch because it forms a bony prominence there. Pain may occur if the accessory bone is overly large causing this bump on the instep to rub against footwear.

Symptoms
Perhaps the most common of the extra bones in the foot, the accessory navicular bone is estimated to be present in 7 to 19 percent of the population. Zadek and Gold maintained that the bone persisted as a distinct, separate bone in 2 percent of the population. Also be aware that the accessory bone normally fuses completely or incompletely to the navicular. It is this incomplete fusion which allows for micromotion, which, in turn, may cause degenerative changes that can also contribute to the pain.

Diagnosis
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
Most doctors will try to find a non-surgical approach to the issue due to costs and complications involved in a surgery. Some non-surgical procedures are: Immobilization which consists of placing the foot in a cast or walking boot to allow rest and decrease inflammation, placing a towel-covered-icepack on the area to reduce inflammation, anti-inflammatory or steroid drugs/injections may be prescribed to reduce swelling and pain, physical therapy may be used to help strengthen muscles and prevent a reoccurrence of symptoms, Orthotic Devices placed in the shoe to help support the arch and prevent a reoccurrence of symptoms.



Surgical Treatment
Fusion of the accessory navicular to the navicular with screws is required when there is a large accessory navicular bone and removal of this bone would reduce the articular surface of the Navicular to the talus (coxa pedis). Fusion will relieve pain without disrupting the tibialis posterior tendon insertion nor narrowing talar head support. In most instances, a patient’s recovery will be as follows. 0-6 weeks: Immobilization (in case or cast boot) non-weight-bearing or touch weight-bearing. 6-10 weeks: Increasing activity in a cast boot. Physical therapy to work on strength and balance. Full recovery after 9 weeks-2 months. In some patients (where the posterior tibial tendon is still intact and functioning) the treating surgeon may allow weight-bearing as tolerated in a cast boot immediately after surgery.