Tarsal Coalition | Symptoms & Causes

What are the tarsal bones, and what is tarsal coalition?

The tarsal bones in the middle and back of the foot—the calcaneus, talus, navicular and cuboid—together form joints that are extremely important to proper foot function. When there’s abnormal growth of bone cartilage or fibrous tissue across these joints (tarsal coalition), a child’s range of motion either decreases or ceases entirely, causing pain and rigidity in the area.

The most common coalitions occur either:

  • across a joint between the talus and calcaneus bones (talocalcaneal coalition, also referred to as a TC bar)
  • between the calcaneus and navicular bones (calcaneonavicular coalition, also referred to as a CN bar)

Calcaneonavicular coalitions are more common than talocalcaneal coalitions. Together, these two types account for about 90 percent of all coalitions. There are other more rare types, as well. More than 50 percent of the time, tarsal coalition occurs in both feet. Sometimes both types of coalition are present in the same foot.

What causes a tarsal coalition?

Torsal coalition can be a genetic error in the dividing of embryonic cells that form the tarsal bones during fetal development can sometimes be triggered by:

  • trauma to the area
  • infection
  • self-fusion of a joint caused by advanced arthritis (rare in children)

What are the symptoms of a tarsal coalition, and when do they show up?

Even though most children with tarsal coalitions are born with them, a child typically has no painful symptoms until sometime between the ages of 8 and 16—with two age peaks for the onset of symptoms (8 to 10 and 11 to 13). Late childhood/early adolescence is the time when a child’s bones are turning from mostly cartilage to mostly bone (ossifying). During this period, the hardening (calcifying) tarsal coalition grows more rigid and painful.

The following are the most common symptoms of a tarsal coalition. Keep in mind that each child may experience symptoms differently:

  • pain, typically on the outside and top of the foot (although some children have no pain)
  • flat feet or a flat foot (although not all children with flat feet have a tarsal coalition)
  • rigidity and stiffness in the affected foot<./li>
  • muscle spasms

Sometimes symptoms don't flare up until early adulthood.

How common is tarsal coalition?

Experts estimate that about 3 to 5 percent of people have a tarsal coalition. About 50 percent of these have it in both feet.

How serious is tarsal coalition?

The answer to this question depends on the child’s and family’s expectations. If sports are central to the child’s life, tarsal coalition could be viewed as a serious problem. If the child has only occasional aches, as when running in gym class, and sports are not very important to them, they probably won’t view the condition as a big problem.

A severe case of tarsal coalition can pose a functional problem for walking and may alter a child’s activity level, but it’s not life-threatening or limb-threatening.

What if tarsal coalition goes untreated?

Over time, a child, teen or young adult may experience enough pain that she can’t do the activities she wants to do. Later in life, they may have a very stiff foot (indicating a large coalition). The foot may be so stiff and painful that there’s no longer an option for surgical repair; in such cases, surgery would be a joint fusion to alleviate the pain.

Who’s at risk for developing tarsal coalition?

Tarsal coalition is a genetically-determined condition. If it occurs sporadically (by chance), it means that a genetic mutation took place during a child’s fetal development. If one of a child’s parents has the condition, there is a chance that the child will also have it.

There is no genetic test available yet for tarsal coalition. As many people living with tarsal coalitions have few or no symptoms and treatment of tarsal coalitions is only for symptomatic ones, evaluation for tarsal coalition occurs only for those people presenting with symptoms.

Will my child be OK?

This condition has a very positive prognosis. Only a small percentage of people who have tarsal coalition need treatment for it. And one-third to one-half of those who need treatment can be helped without surgery.

Of those who are treated (removed either non-surgically or surgically), about 75 percent become free from pain or recurrence of the condition.

There is a potential for the repaired joints or surrounding joints to develop arthritis later in a person’s life.

What should I ask my doctor if my child has tarsal coalition?

Some of the questions you may want to ask include:

  • What’s wrong with my child’s foot (feet)? Why is she having pain?
  • Are other tests needed to confirm this diagnosis?
  • Does my child need treatment? Does she need surgery?
  • Is there, or could there be, damage to her tissues or blood vessels?
  • Could there be long-term effects? Pain? Arthritis?
  • Could this condition affect my child’s ability to walk, run or play sports?
  • How long should my child be followed by her care team?

Q: If my child has tarsal coalition, is she at risk for arthritis or other conditions later in life?
For most children with mild cases of tarsal coalition, there’s no added risk of developing arthritis as a result of the condition. For children with more severe cases of the condition, adulthood can bring some risk for arthritis in the affected joint or surrounding joints.

Q: What is the main risk factor for tarsal coalition?
A child has a genetic predisposition for developing tarsal coalition(s) if one parent has the condition.

Q: What is Boston Children’s experience treating developmental bone problems in children and teens?
At Boston Children’s Hospital, we’re known for our clinical innovations, research breakthroughs and leadership in treating lower-extremity bone problems. Boston Children’s Hospital 's Orthopedic Center offers the most advanced diagnostics and treatments—several of which were pioneered and developed by Boston Children’s researchers and clinicians.


  • can be a genetic error during fetal development in the dividing of the embryonic cells that form the tarsal bones
  • can be triggered by:
    • trauma
    • infection
    • advanced arthritis (rare in children) causing self-fusion of a joint

Signs and symptoms

  • pain (in some children), usually on the outside and top of the affected foot
  • flat feet or a flat foot (not all children with flat feet have a tarsal coalition)
  • rigidity and stiffness
  • muscle spasms

When to seek medical advice

Contact your child’s doctor if your child has:

  • pain on the outside and top of the affected foot
  • flat feet or a flat foot
  • a rigid or stiff foot
  • muscle spasms in her foot

Questions to ask your doctor

If your child is diagnosed with tarsal coalition, you may feel a bit worried. It can be easy to lose track of the questions that occur to you. Lots of parents find it helpful to jot down questions as they arise—that way, when you talk to your child’s doctors, you can be sure that all your concerns get addressed.

Some of the questions you may want to ask include:

  • Could you describe what’s wrong with my child’s foot (feet)?
  • Are other tests needed to confirm this diagnosis?
  • Is there, or could there be, damage to her tissues or blood vessels?
  • Does my child need treatment? Does she need surgery?
  • Could there be long-term effects? Pain? Arthritis?
  • Could this condition affect my child’s ability to walk, run or play sports?
  • How long should my child be followed by her care team?


Most of the time, the pain associated with tarsal coalition goes away with non-surgical treatment and therapy. But if your child’s case is severe enough to need surgery, the majority of procedures at Boston Children’s Hospital are successful, and occur without major complications. As with most surgery, after the procedure patients are at a very small risk for infection or bleeding.

The main complication is that about 25 to 30 percent of affected children—who have non-surgical or even surgical treatment—still have some level of pain.

Long-term outlook

The long-term outlook for this condition is very positive. Many of the time, it can be corrected by rest and non-surgical treatment. The condition isn’t usually associated with any other underlying conditions or syndromes.

Of those who are treated either non-surgically or surgically, about 75 percent become free from pain and recurrence of the condition.

Tarsal coalition glossary

  • arthritis: joint inflammation and damage, resulting in pain, swelling, stiffness and limited movement. Arthritis can occur when a joint’s cushioning cartilage wears away
  • bilateral: both of two sides
  • bone bridge: another term for the coalition that forms between the tarsal bones
  • calcify: harden into bone by the deposit of calcium salts into cartilage; ossify
  • The Center for Families at Boston Children’s Hospital: dedicated to helping families find the information, services and resources they need to understand their child’s medical condition and take part in their care
  • CT scan (computerized tomography scan): the gold standard for the diagnostic imaging of tarsal coalitions; uses a combination of x-rays and computer technology to produce cross-sectional horizontal and vertical images (called "slices") of the body
  • diagnosis, diagnostics: identifying disease or injury through examination, testing and observation
  • gait: manner of walking
  • lower extremities: parts of the body from the hip to the foot—includes hip, thigh, ankle, leg and foot
  • MRI (magnetic resonance imaging): a diagnostic imaging tool that produces detailed images of organs and structures within the body
  • onset (of signs or symptoms): the first appearance of signs or symptoms
  • orthopedic surgeon, orthopedist: a doctor who specializes in surgical and non-surgical treatment of the skeletal system, spine and associated muscles, joints and ligaments
  • orthopedics: the medical specialty concerned with diagnosing, treating, rehabilitating and preventing disorders and injuries to the spine, skeletal system and associated muscles, joints and ligaments
  • ossify: a natural progression as a child grows in which cartilage turns into bone or bony tissue
  • prognosis: outlook for the future
  • resection: a surgical procedure in which an organ or body structure is removed
  • sporadic: by chance
  • tarsal coalition: an inherited condition in which there’s an abnormal connection between two or more of the tarsal bones. These coalitions can form across joints of the foot or can occur between bones that don't normally have a joint between them.
  • x-rays: a diagnostic test that uses invisible electromagnetic energy beams to produce images of internal tissues, bones, and organs onto film; “standing” x-rays are x-rays taken while the child is standing up, as in diagnosing tarsal coalition

See our extensive Glossary of Orthopedic Terms.

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