A tarsal coalition is an abnormal connection involving two or more bones in the back of the foot. Fusion of the bones causes the foot to become rigid and restricts proper movement. Tarsal coalition is a condition that is present at birth but does not necessarily manifest until early adolescence. When it does show up, daily activities may become difficult due to pain and stiffness in the foot.

Your feet have many bones located in three different areas: the forefoot, midfoot and hindfoot. In the midfoot and hindfoot are the tarsal bones. Of the seven bones in this area, three are most commonly involved in tarsal coalition: the calcaneus, talus and navicular bones.

A tarsal coalition occurs as a result of two or more of these bones growing into one another. They are connected by a bridge of bone or cartilage. These growths can cover a small portion of the joint space, or they can expand over a large area of the joint. In most cases, either the calcaneus and navicular bones are connected or the talus and calcaneus bones are. In some instances, other joints may also be involved.

Roughly one percent of the population may have a tarsal coalition. Many do not have any symptoms. About 50% of those with this condition have it in both feet. A tarsal coalition actually begins before birth, caused by a gene mutation. The cells that produce the tarsal bones are affected. Although the condition begins before birth, it is often not discovered until the child is older or reaches adolescence.

During pre-adolescence and adolescence, the cartilage of a child’s foot begins to mineralize or ossify as the bone matures. The result is hard, calcified bone. If a tarsal coalition is present, this cartilage may also ossify, causing the tarsal bones to fuse together. This may happen between 8-16 years of age, and the child will experience pain and stiffening in the hindfoot.

Treatment for Tarsal Coalition

Nonsurgical treatments may be appropriate to start. These include reducing the stress on the tarsal bones. Avoiding high impact activity for 3-6 weeks may reduce the pain. Arch supports may also be recommended to help stabilize the foot. Immobilization of the foot can also take stress off the tarsal bones. This can be achieved by wearing a temporary boot or cast. Pain relief may also be achieved with steroid medications.

When these treatments are not effective, surgery may be advised to improve function and relieve pain. The type of surgery indicated depends on the size and location of the coalition.

If your child is experiencing pain in the hindfoot, contact Dr. Mogul, an expert in foot and ankle surgery. Make an appointment for examination and consultation to relieve your child’s foot pain and restore mobility.