What is it?
An accessory navicular is an extra piece of bone that is found on the inner side of the arch next to the navicular bone in the foot. It is usually first noticed during adolescence, and is more common in females as opposed to males. Typically, patient’s will notice a prominent bone on the inside of their arch.
What are the symptoms?
Most patients who have an accessory navicular are usually unaware of the condition as it causes no symptoms. Symptoms that patient’s may experience include:
- Dull ache (in the midfoot/ arch)
- Tenderness over the navicular/ posterior tibial tendon
- Difficulty finding comfortable footwear
- Prominent navicular
- Inflammation/ swelling
- Poor foot type (flat foot)
Why did I get it?
An accessory navicular bone is present at birth and therefore, does not affect everyone. During development as activity levels increase the surrounding muscles and tendons are placed under higher loads, the accessory navicular can become a problem.
Some individuals will develop accessory navicular syndrome, a painful condition where the bone and/ or posterior tibial tendon on the inside of the ankle become irritated. This can result from any of the following
- Trauma (e.g. ankle sprain)
- Irritation over time from footwear rubbing against the accessory bone
- High levels of activity or overuse
How is it diagnosed?
Taking a thorough history as well as assessing the injury, movement and pain through a detailed clinical examination is typically adequate in providing an accurate diagnosis. Referral for an x-ray is also usually required to confirm the diagnosis.
How can I treat it?
- Non-steroidal anti-inflammatories
- Rest, ice, compression and elevation
- Activity modification/ decreased time weight bearing
- Immobilisation
- Padding and strapping
- Footwear modifications
- Strengthening program
- Custom orthotics
- Surgery- last resort for non-responsive cases
