What is an accessory navicular bone?
An accessory navicular is an extra bone or bit of cartilage material within the arch of the foot that might or may not produce symptoms. It is also known as an os navicularum or os tibiale externum. The bone is integrated within the tendon of the posterior tibial muscle which inserts in the navicular. The excess bone is on the inside side of the navicular bone that is the bone which is near the top of the arch of the foot. It is present in from 5-15% of the population. It's not often an issue, however the prominence of the bone can make pressure from the footwear painful. At times the bone is at such a location which it will modify the angle of action with the posterior tibial muscle that might impact foot function and might trigger any number of dysfunctional concerns, for instance a flat foot.
The diagnosis is generally by a x-ray where the presence of the extra bone is pretty obvious. There are several varieties that the x-ray can help confirm which one it is. The Geist grouping separates the accessory navicular bones into three different types. Each of the 3 varieties affects the structure and function of the feet in different ways and each of the three differing types must have a distinct treatment method.
The aim of treatment is to relieve the symptoms and prevent it being painful. If the pain is quite bad, then placing the foot within a cast or easily-removed walking brace allows the affected region to rest which helps the pain. Ice can also be used to decrease inflammation. Oral nonsteroidal anti-inflammatory drugs (NSAIDs) may be used along with immobilization to further reduce the pain and swelling. Exercises and treatment options to strengthen the muscles could also be encouraged, in particular in the long run to help you avert a repeat in the signs and symptoms. Foot orthotic inserts are usually also very useful to defend the foot and become mainly beneficial if the accessory navicular is causing a flat foot.
The accessory navicular bone may be a unique problem is sports activities for example skiing and also ice skating. This is because the footwear of these sporting activities goes around the feet and its quite inflexible. Therefore, if someone has a enlarged bit of bone on the foot, such as an accessory navicular, this can be fairly painful and in addition tricky to manage. Items like doughnut type pads to remove the force from the boot off of the spot is oftentimes useful. This can be where the techniques of a boot maker or a competent ski boot fitter might be invaluable. These experts are used to handling these types of problems and can modify the boot around the enlarged bone making it much more comfortable. A podiatrist can frequently assist with all this.
If the conservative nonsurgical therapies really don't reduce the symptoms, after that surgery can be indicated. Surgical procedures may require getting rid of the extra bone, re-shaping the region and reconstructing the tendon insertion to better its biomechanics. This accessory bone is not required for normal foot function, therefore theoretically it will not be an issue.