Accessory Navicular Syndrome
An accessory navicular is a small extra bone found next to the navicular on the inside border of your foot, just up from (proximal to) the ankle. It’s the most common accessory bone in the foot, occurring in up to 5-10% of people. It is incorporated into the posterior tibial tendon which passes down the inside of the foot.
Accessory navicular syndrome describes a condition in which the accessory bone or posterior tibial tendon becomes irritated and produce painful symptoms.
While the exact reason for the development of the accessory navicular bone itself is unknown, there is thought to be a genetic factor involved for some people.
Accessory navicular syndrome is caused by irritation or damage to the area of the navicular and the surrounding soft tissues. This may occur from:
Some people with an accessory navicular will remain asymptomatic throughout their lifetime and may never even know they have an accessory navicular. For others, painful symptoms can develop. Symptoms may begin during growth spurts and periods of bone maturity between the ages of 8 – 16 years, or may not begin until adulthood. Symptoms may include:
Treatment begins with relieving the painful symptoms through the resting and icing the foot. Following this, the focus is on relieving strain and pressure away from the area of the navicular to reduce the likelihood of irritation and the symptoms coming back. This may involve:
For those that don’t respond to conservative management and have ongoing painful symptoms, surgery may be indicated.