Today we are discussing a lump or bone that sticks out on the inside of the foot near the ankle joint. This is the navicular bone. The navicular bone can be enlarged or have an extra bone (accessory navicular). In both these cases, there can be a significant firm bony protrusion in this part of the foot. This can be painful just from direct pressure. This can also be painful because there is an important tendon that attaches to this bone to help support the foot. This is the posterior tibial tendon. Its job is to help provide support both medial and vertical support to the inside of the arch to keep it from collapsing and to help stabilize the entire foot.

This attachment point can be overstressed with a pronated low arch foot structure. Basically the tendon has to work too hard and there can be pain and inflammation with the tendon attaches to the navicular. In other cases the tendon attaches to the accessory navicular bone which then attaches to the main navicular bone. This weakens the attachment point and creates more potential problems. In some cases, the accessory navicular has to be removed. This foot surgery procedure is called a Kidner procedure and is done at approximate 13 years of age with a range of 9 to 16 years of age for children. This is sometimes done in adults also. When the accessory bone is removed and the tendon is repaired it often improves the mechanical function of the tendon at this point. It also eliminates the inflamed and symptomatic accessory bone. The accessory navicular very common and is present in approximately 5-10% of the population. For milder cases, ankle braces orthotics and athletic taping can all offer some symptomatic and functional improvement with the painful accessory navicular.

If you or your children are experiencing foot or ankle pain, give us a call today at 425-391-8666 or make an appointment online today.