Tarsal Coalition

Have you noticed that your child’s foot seems stiff when he walks? Does (s)he have flat arches? Is there any pain during walking and other activities? If so, (s)he may be suffering from an inherited condition called tarsal coalition.

What is Tarsal Coalition?

Tarsal coalition can make walking and other activities painful. Usually this condition develops in the womb when the feet are forming. An abnormal band of tissue will form between these two bones. With a high level of activity (such as running), the pain and stiffness associated with tarsal coalition will increase.

How Tarsal Coalition Forms

The foot and ankle contain 26 bones, and seven of these bones are in a group called the “tarsal bones”. These are located towards the back of the foot, including the heel area. If two or more bones in this area are joined together, it is called a “tarsal coalition”. The two most common sites affected are between the calcaneus and the talus, and between the calcaneus and the navicular.

When Does Tarsal Coalition Develop?

Although tarsal coalition is generally believed to develop while a baby is growing in the womb, the condition is not usually identified until the child is older. A child still has a lot of cartilage, and their bones are still forming. As the cartilage hardens, the bands of tissue connecting the two foot bones may also harden, leading to pain and stiffness. Children between the ages of 8-16 are most often diagnosed with tarsal coalition. It’s estimated that the rate of occurrence is about 1 in 100 people, but many are never formally diagnosed as the coalition is too small to cause a problem.

Symptoms

If the coalition is small, there may never be any symptoms. A large band of tissue that has hardened can cause stiffness in the foot. The stiffness also leads to pain.

The pain will be felt below the ankle and towards the back of the foot. This condition is a type of flatfoot, so you will notice that the foot is flat to the ground instead of having a natural arch. The foot is also more rigid than a normal foot. The rigidity and flatness make walking more difficult on uneven surfaces. Someone who has a tarsal coalition may subconsciously roll their ankle more while walking, which can lead to frequent ankle sprains.

How is Tarsal Coalition Diagnosed?

A physical exam of the foot may be all the doctor needs to make a diagnosis. The flatness of the foot is one sign, as well as any stiffness while walking. The doctor will check for arches in the feet, especially while the patient is standing on their tiptoes. Even though a physical exam may be enough to diagnose tarsal coalition, a CT scan may also be ordered. This test gives a better view of all the bones in the foot, and will help the doctor see which bones are affected and how large the band is that is connecting the bones. Regular x-rays may also be used.

Is Surgery Necessary for Treatment?

If the coalition is not affecting daily life, the doctor may simply recommend some braces or orthotics in your shoes. A temporary boot or cast may be tried to see if the condition can correct itself. Injections can help with the pain, but are not a cure for the condition. If braces and casting do not help, the next option is surgery.

Types of Surgery

There are two types of surgery used to correct tarsal coalition. With either type of surgery, a cast will need to be worn for a few weeks following the procedure. Weight cannot be put on the foot during recovery. After the cast has come off, most patients have reduced pain and increased mobility. The two types of surgery include:

Resection: This is the most common type of surgery used to correct tarsal coalition. The coalition is removed and soft tissue from elsewhere in the body is put in its place. This successfully eradicates the problem and restores full mobility to the patient.
Fusion: Larger or more severe cases of tarsal coalition may need to be corrected by fusion. This procedure limits the movement of the joints and puts the bones in their proper place. Screws, pins, or plates may be used to hold the bones together.