From left to right: Webbed skin between fingers or toes is a common feature of syndactyly. Fingers or toes may be joined all the way from the base to the tip or only partway up.

What is syndactyly?

Having fingers or toes that are joined is called syndactyly (sin-DAK-til-ee). In most cases, the digits are joined side-by-side only by skin or other soft tissue, which may look webbed. The fingernails or toenails may also be joined.

Sometimes the digits are joined at the bone. There may be other problems with the phalanges (fah-LAN-jeez) in the joined digits, such as extra, missing or misshaped phalanges. The digits may share connections between their muscles, tendons, nerves and blood vessels, too.

It is possible 2, 3, 4 or all 5 digits on a hand or foot may be joined. The joined section may go only partway from the base of the fingers or toes to the tip (partial or incomplete syndactyly) or all the way from the base to the tip (complete syndactyly).

  • Syndactyly in children

    This is a fairly common condition. It happens in about 1 in 2,000 to 1 in 3,000 babies. It’s passed down in some families (inherited). Often it happens to only 1 person in a family because of changes in their genes.

    About half of babies born with syndactyly have it on only 1 hand or foot. About half have it on both hands or feet.

    When a baby’s hands and feet begin to form, they are shaped like mittens or paddles. Then the fingers and toes divide. In most babies with syndactyly, the fingers or toes did not divide all the way. In babies with amniotic band syndrome, the fingers or toes may have divided and then joined again as they healed after injury (acrosyndactyly).

    Many babies with syndactyly have no other differences in their bodies and no health problems. But this condition can happen along with other hand or foot conditions, such as polydactyly (then it’s called polysyndactyly) or with other geneticconditions or other syndromes, such as Apert syndrome.

Syndactyly at Seattle Children’s

Each year we see many babies with this condition in our clinics, and we create a tailored treatment plan for each of them to get the best results.

  • The compassionate experts you need are here

    Syndactyly is among the most common congenital conditions treated by the experts in our Hand and Upper Extremity Program.

    For many of our patients, treatment means surgery – sometimes highly complex surgery – to divide digits. Our surgeons are experienced at performing this type of surgery in children.

    When needed, our rehabilitation program provides occupational therapy to help children with syndactyly gain the best possible use of their hands or feet.

    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.

  • Treating the whole child

    Within Orthopedics, your child is cared for by a team with vast experience, including pediatricians, pediatric orthopedic surgeonsnurse practitioners, physician assistants, nurses, athletic trainers, certified medical assistants, registered orthopedic technologists and sports physical therapists.

Symptoms of Syndactyly

Children with syndactyly are born with 2 or more fingers or toes that are joined. The joined digits may look webbed, and they may not move well.

For some children, syndactyly is only 1 feature of a more complex genetic condition or other syndrome. These children will have other signs and symptoms.

Diagnosing Syndactyly

If your child is born with joined fingers or toes, the doctor will examine your child carefully. During the exam, 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 phalanges are joined or only the skin and soft tissues are joined. If the doctor thinks your child might have a more complex condition linked with syndactyly, your child may have other tests.

Treating Syndactyly

Joined toes rarely need treatment because they rarely cause any problems with a child's function. If syndactyly makes your child’s toes grow at an angle that’s not typical, your child may need surgery to divide the toes.

Doctors almost always perform surgery to divide joined fingers in early childhood. The goal is to give your child hands that work well and look typical. Rarely, doctors leave 2 fingers joined. Your child’s doctor may recommend this if the digits work well as a unit but are not likely to work apart because they share nerves, blood vessels and tendons.

Surgery for Syndactyly

  • Dividing digits

    If only 2 digits are joined and they are joined only by skin, the surgery will be simpler. If more digits are joined or the digits are joined at the bone, the surgery will be more complex. In any case, it is often done as day surgery.

    The basic method for the surgery is to make zigzag cuts (incisions) between the digits to divide them. The zigzag shape gives the surgeon pointed flaps of skin to wrap around each digit. This method helps prevent scars that could restrict growth later.

    Near the base of the digits, the surgeon cuts another flap of skin that gets folded over to make a typical web between the digits. The surgeon sews all the flaps in place.

  • Skin grafts

    Most children need skin grafts to cover the digits completely after they are divided. The zigzag method reduces the need for skin grafts. But sometimes the flaps are not big enough. The surgeon takes a small patch of skin, usually from the child’s forearm or their belly near their hipbone, to close up the area around the digits.

  • After surgery

    After surgery, your child will need to wear a cast. The doctor will want your child to come back for follow-up visits to make sure they are healing well. At a follow-up visit, the cast will be removed and an occupational therapist will fit your child with a splint. This helps prevent scarring and shortening of tissue (contractures). Some children who have extensive surgery, cutting through many tissues, may have occupational therapy to help with swelling, scarring and stiffness.

  • Surgery timing

    The timing of surgery varies. Your child’s team will work with you to make a plan based on your child’s needs.

    In general, surgery needs to be done earlier for digits joined in a more complex way. Dividing the digits early can prevent problems that might happen as your child grows. A digit that is joined to its neighbor may grow at an angle or become twisted because the digits grow at different rates.

    In most cases, surgeons divide the thumb from the first finger and the ring finger from the little finger around the age of 6 months. If any of the middle 3 fingers are joined, they are usually divided after the age of 1 year.

    If your child has 3 or more joined digits, they will need more than 1 surgery. The surgeon will work on only 1 side of a digit, not both sides, during 1 surgery. This reduces the risk for problems with blood flow to the digit.

Contact Us

Contact Orthopedics and Sports Medicine at 206-987-2109 for an appointment, a second opinion or more information.

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