Tarsal Coalition

Tarsal coalition is a type of flatfoot. It occurs when 2 or more of the tarsal bones, found in the middle and back of the foot, join together. These bones are usually separate.

Tarsal coalition belongs to the category of flatfoot called rigid flatfoot. The feet of children with tarsal coalition look the same as the feet of children with other forms of flatfoot. Their feet angle outward from the leg, and they do not have an arch in the middle. But feet with a tarsal coalition are stiff, not flexible, like some other forms of flatfoot.

About 1% to 2% of people have tarsal coalition. The good news is that only about a quarter of people who have tarsal coalition have problems with it or need treatment. Of those who need treatment, a third to half are helped without surgery.

• What can cause tarsal coalition?

  Tarsal coalition is an inherited (genetic) condition. Parents with tarsal coalition can pass it on to their children. It is not associated with any other medical problems. Unlike with other forms of flatfoot, babies are not born with a tarsal coalition. Instead, their feet flatten out as they get older, usually between the ages of 8 and 16.

  Each of the tarsal bones has a name. The most common sites for a tarsal coalition are between the calcaneus and navicular bones and between the talus and calcaneus bones. About half of cases involve the first set of bones, and about half involve the second set. In some cases, both sets of the bones are joined together in the same foot.

Tarsal coalition is treated by the experts in our Foot and Ankle Deformities Program.

• Specialists for all your child’s needs

  Many of our pediatric orthopedic surgeons have expanded fellowship training in areas such as foot and ankle conditions, sports medicine, tumors, upper extremity surgery, limb deformity, neuromuscular diseases, skeletal dysplasia and spine problems. To restore or improve your child’s health, function and quality of life, we often use nonsurgical methods (like medicines, physical therapy and braces), recommending surgery only when we believe it will give your child the best results.

  We have the largest group of board-certified pediatric radiologists in the Northwest. Our radiologists have special expertise using ultrasound to look for bone and joint changes so we can work with your child to help prevent future problems. If your child needs imaging that uses radiation, we use the lowest amount possible to produce the best image. We also have a 3D low-dose radiation X-ray machine, called the EOS, for safer full-body 3D images.