Accessory Tarsal Navicular Pain

Overview
Some people, possibly beginning in early adolescents, but perhaps later, can develop a painful bump on the side of their foot. The pain may be worse after athletic activity or just normal walking, and walking itself may become painful. This pain may become constant, but it will tend to improve with continued rest. Depending on the size of the bump, it may rub against shoes, or cause pain if the bump is hit by something. Over time, the arch of the foot may be lost and a flat food will develop.



Causes
This painful foot condition is caused by an extra bone in the foot called the accessory navicular. Only about 10% of people have this bone (4 to 21%), and not all of them will develop any symptoms. The navicular bone is one of the normal tarsal bones of the foot. It is located on the inside of the foot, at the arch.

Symptoms
One obvious problem with the accessory navicular is that it may be large and stick out from the inside of the foot. This can cause it to rub against shoes and so become quite painful. The fibrous connection between the accessory navicular and the navicualar, as well, is easy to injure, also leading to pain. This is kind of like a fracture, and such injuries cause the bone to move around too easily, leading to pain with activity. When the connection between the bones is injured in this way, the two bones do not always heal properly, so pain may continue unabated.

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
Most cases of accessory navicular syndrome may be treated conservatively with some sort of immobilization. This should allow the fibrous tissue between the two bones to heal. If a patient is extremely flat footed (pronated) then I lean more towards an orthotic than a boot as my main goal is to keep the patient's foot from flattening out too much and thus reduce the strain on the two bones. Supplementation with ice, oral anti-inflammatory medication. If the patient is athletic sometimes we can keep them active with an orthotic, but other times they have to give up their sport for a period of time to allow the condition to heal.



Surgical Treatment
Depending upon the severity the non operative or conservative treatment should be maintained for at least 4- 6 months before any surgical intervention. There are 2 surgeries that can be performed depending upon the condition and symptoms. First is simple surgical excision. In this generally the accessory navicular along with its prominence is removed. In this procedure, skin incision is made dorsally to the prominence of accessory navicular. Bone is removed to the point where the medial foot has no bony prominence over the navicular, between the head of the talus and first cuneiform. Symptoms are relieved in 90% of cases. Second is Kindler procedure. In this the ossicle and navicular prominence is excised as in simple excision but along with the posterior tibial tendon advancement. Posterior tibial tendon is split and advanced along the medial side of foot to provide support to longitudinal arch. After surgery 4 week short leg cast, well moulded into the arch with the foot plantigrade is applied. Partial weight bearing till the 8th week and later full weight bearing is allowed. When the cast is being removed can start building up the ROM to counter atrophy and other physical therapy treatment which include stretching and strengthening exercises.