Large Accessory Navicular Bone

Overview
The accessory navicular is an ossicle, or extra bone located medially to the navicular. Depending on the type, or stage, it may be connected to the navicular by a fibrous union, via a type of joint called a synchrondrosis. In those who have this extra bone, it is present at birth, but it starts as soft cartilage and then begins to ossify (turn into bone) at around age nine. Some sources believe that, in about half of those who have it, the bone will fuse to the navicular in late adolescence, but it is not clear that this actually happens.



Causes
This can result from any of the following. Trauma, as in a foot or ankle sprain. Chronic irritation from shoes or other footwear rubbing against the extra bone. Excessive activity or overuse. Many people with accessory navicular syndrome also have flat feet (fallen arches). Having a flat foot puts more strain on the posterior tibial tendon, which can produce inflammation or irritation of the accessory navicular.

Symptoms
Many people have accessory (?extra?) naviculars (figure 1) - a prominent extra bone extending from the navicular bone. Most accessory naviculars are completely asymptomatic. However, some individuals will develop pain on the inside of their midfoot. Pain may occur from the pressure of the shoe ware against the prominence, irritating either the bone itself or the fibrous junction where the accessory bone meets the regular navicular. Alternatively, the fibrous junction or interface may become painful as a result of tension applied by the posterior tibial tendon through its connection or insertion at that site. Often, individuals will be asymptomatic for years, however, a new pair of shoes or a change in their activity level can cause symptoms. The accessory navicular itself typically develops during adolescence, when the two areas of the navicular bone fail to fuse together.

Diagnosis
To diagnose accessory navicular syndrome, medical staff ask about the patient?s activities and symptoms. They will examine the foot for irritation or swelling. Medical staff evaluate the bone structure, muscle, joint motion, and the patient?s gait. X-rays can usually confirm the diagnosis. MRI or other imaging tests may be used to determine any irritation or damage to soft-tissue structures such as tendons or ligaments. Because navicular accessory bone irritation can lead to bunions, heel spurs and plantar fasciitis, it?s important to seek treatment.

Non Surgical Treatment
Traditional medicine often falls short when it comes to treatment for this painful condition. As similar to other chronic pain conditions, the following regimen is usually recommended: RICE, immobilization, anti-inflammatory medications, cortisone injections, and/or innovative surgical options. Clients familiar with Prolotherapy often say? no thanks? to those choices, as they know these treatments will only continue to weaken the area in the foot. Instead, they choose Prolotherapy to strengthen the structures in the medial foot.



Surgical Treatment
If conservative measures do not seem to help, however, you may need to have surgery to make adjustments to the bump. This could include reshaping the little bone, repairing damage to the posterior tibial tendon, or even removing the accessory navicular altogether.