Overview
Not everyone has the same number of bones in his feet. It is not uncommon for both the hands and the feet to contain extra small accessory bones, or ossicles, that sometimes cause problems. This guide will help you understand where the accessory navicular is located, why the extra bone can cause problems and how doctors treat the condition.
Causes
People who have an accessory navicular often are unaware of the condition if it causes no problems. However, some people with this extra bone develop a painful condition known as accessory navicular syndrome when the bone and/or posterior tibial tendon are aggravated. 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.
Symptoms
If you develop accessory navicular syndrome, you may experience a throbbing sensation or other types of pain in your midfoot or arch (especially while or right after you use the foot heavily, such as during exercise), and you may notice a bony prominence on the interior of your foot above the arch. This prominence may become inflamed, which means it will likely feel warm to the touch, look red and swollen, and will probably hurt.
Diagnosis
An initial assessment is an orthopaedic office begins with a thorough history and complete physical exam, including an assessment of the posterior tibial tendon and areas of tenderness. Associated misalignments of the ankle and foot should be noted. Finally, weight-bearing x-rays of the foot will help in making the diagnosis. Sometimes, an MRI may be needed to see if the posterior tibial tendon is involved with the symptoms or getting more clarity on the anatomy of the accessory navicular.
Non Surgical Treatment
Many individuals with symptomatic accessory naviculars can be managed successfully without surgery. Standard non-surgical treatment includes shoes that are soft around the inside of the ankle can allow for any excess prominence of bone. Therefore, it is recommended that either shoes with plenty of padding and space in the ankle area are purchased, or pre-owned shoes can be modified by a shoemaker to create extra space in this area. For example, many patients will get their ski boots expanded in the area around the prominence, minimizing irritation. In addition, a shoe with a stiff sole will help disperse force away from the arch of the foot during walking, thereby minimizing the force on the posterior tibial tendon. An off-the-shelf arch support may help decrease the stress applied by the posterior tibial tendon. If necessary, an ankle brace applied to provide more substantial support to the arch may be successful where a simple arch support fails.
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.
Not everyone has the same number of bones in his feet. It is not uncommon for both the hands and the feet to contain extra small accessory bones, or ossicles, that sometimes cause problems. This guide will help you understand where the accessory navicular is located, why the extra bone can cause problems and how doctors treat the condition.
Causes
People who have an accessory navicular often are unaware of the condition if it causes no problems. However, some people with this extra bone develop a painful condition known as accessory navicular syndrome when the bone and/or posterior tibial tendon are aggravated. 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.
Symptoms
If you develop accessory navicular syndrome, you may experience a throbbing sensation or other types of pain in your midfoot or arch (especially while or right after you use the foot heavily, such as during exercise), and you may notice a bony prominence on the interior of your foot above the arch. This prominence may become inflamed, which means it will likely feel warm to the touch, look red and swollen, and will probably hurt.
Diagnosis
An initial assessment is an orthopaedic office begins with a thorough history and complete physical exam, including an assessment of the posterior tibial tendon and areas of tenderness. Associated misalignments of the ankle and foot should be noted. Finally, weight-bearing x-rays of the foot will help in making the diagnosis. Sometimes, an MRI may be needed to see if the posterior tibial tendon is involved with the symptoms or getting more clarity on the anatomy of the accessory navicular.
Non Surgical Treatment
Many individuals with symptomatic accessory naviculars can be managed successfully without surgery. Standard non-surgical treatment includes shoes that are soft around the inside of the ankle can allow for any excess prominence of bone. Therefore, it is recommended that either shoes with plenty of padding and space in the ankle area are purchased, or pre-owned shoes can be modified by a shoemaker to create extra space in this area. For example, many patients will get their ski boots expanded in the area around the prominence, minimizing irritation. In addition, a shoe with a stiff sole will help disperse force away from the arch of the foot during walking, thereby minimizing the force on the posterior tibial tendon. An off-the-shelf arch support may help decrease the stress applied by the posterior tibial tendon. If necessary, an ankle brace applied to provide more substantial support to the arch may be successful where a simple arch support fails.
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.