Physical Therapy Exercises For Accessory Navicular Syndrome

Overview
The bones of the foot occasionally develop abnormally in a child and an extra bone called an accessory navicular is present towards the inside of the foot, in front of the ankle. This bone is present in approximately 10% of the general population but not large enough to cause symptoms in the majority of these individuals. The extra bone lump present in childhood can be quite uncomfortable because it rubs on shoes. In addition, the feet associated with the accessory navicular are invariably flat. If the child is active and involved in various athletic activities, this will aggravate the inflammation of the tendon that attaches to the accessory navicular. This tendon is called the posterior tibial tendon and is responsible for maintaining the strength of the arch of the foot. The flat-footedness associated with the accessory navicular usually brings the child for treatment.



Causes
Let us see the reasons why the tendon or the bone would get aggravated. Ankle or foot sprain, irritation of the bone caused by footwear, overusing the foot, quite common in athletes and dancers. People born with this extra bone are also known develop flat feet which also adds to the strain on the posterior tibial tendon and lead to the syndrome.

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
Ideally, getting rid of the symptoms of accessory navicular syndrome will involve soothing the inflammation and irritation in your foot. So, for starters, your podiatrist may have you rest the area, allowing the inflamed tendon and bone to heal. This may be accomplished by wearing a cast or boot designed to keep you from moving the problem area. Your podiatrist may also suggest using ice to reduce the swelling and inflammation, and anti-inflammatory medications (like ibuprofen, or sometimes a cortisone shot or other steroid medication).



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.