The medical term for two or more fingers or toes that are fused together or “webbed” is syndactyly (sin-dak-tuh-lee). If your child has it, it was present at birth.

Webbed fingers or toes:

• Are fairly common and often run in families
• Occur in about one out of every 2,500-3,000 newborns
• Affect boys more often than girls
• Affect both hands about 50 percent of the time
• Can occur alone or as part of a genetic syndrome, such as Down syndrome
• Can sometimes be seen prior to birth by ultrasound
• Most commonly involve the middle and ring fingers

Cause of Webbed Fingers or Toes

When a baby develops in the womb, at first the hands and feet form in the shape of a paddle. Then, around the sixth or seventh week of pregnancy, the hands and feet begin to split and form fingers and toes. In the case of webbed fingers or toes, this process is not completed successfully, leading to digits (fingers or toes) that are fused together or webbed.

In most cases, webbing of the fingers or toes occurs at random, for no known reason. Less commonly, webbing of the fingers and toes is inherited.

Webbing can also be related to genetic defects, such as Crouzon syndrome and Apert syndrome. Both syndromes are genetic disorders that can cause abnormal growth of the bones in the hands and feet.

Symptoms

Digits that are fused or joined may look webbed, and they may not move well.

For some children, having webbed fingers and / or toes is only one symptom of a more complex genetic condition or syndrome. These children will have other signs and symptoms.

Diagnosis

If your child is born with webbed fingers and / or toes, the doctor will check for other signs to tell whether your child has a more complex condition.

Your child may need an X-ray to see whether the bones are joined or only the skin and soft tissues are joined. If the doctor thinks your child might have a more complex condition, your child may have other tests.

Treatment

All except the mildest forms of webbed fingers and some webbed toes are treated surgically.

Surgery can range from fairly simple to very complex depending on the degree of fusion between the digits.

Surgery

Surgery is done under general anesthesia, which means your child is given a combination of medications to put him or her to sleep. Your child should not feel pain or have any memory of the surgery. Children usually have the surgery between the ages of 1 and 2 because it is when the risks of anesthesia are lower.

During surgery, the webbing between the fingers or toes is split evenly − in the shape of a Z. In some cases, extra skin is needed to completely cover the newly separated fingers or toes.

If this happens, skin may be removed from the upper arm or another area to cover these areas; this procedure is called a skin graft. Often only two digits are operated on at a time. Depending on your child’s particular case, several operations may be needed for one set of digits.

After Surgery

After surgery, your child’s hand or foot will be in a cast. The cast stays on for about three weeks before it is removed and replaced with a brace. A rubber spacer may also be used to help keep your child’s fingers or toes separated while he or she sleeps.

It’s also possible that your child will have physical therapy after surgery to help with stiffness, movement and swelling.

Your child will need to have regular doctor’s appointments to check the progress of his or her fingers and toes. During these checkups, your child’s doctor will make sure that the incisions have healed properly. The doctor will also decide whether your child will need additional procedures.