Syndactyly (Webbed Fingers and Toes)

Syndactyly is a condition present at birth where two or more fingers or toes are joined together. The connection may involve just the skin or include bones and soft tissue.

At Banner Children’s, our experienced pediatric orthopedic specialists work with families like yours every day. We’ll walk you through every step of diagnosis, treatment and recovery to ensure your child can grow, play and thrive. 

What is syndactyly?

Syndactyly (pronounced sin-DAK-tuh-lee) happens when fingers or toes don’t fully separate during a baby’s growth in the womb. The word comes from Greek and means “joined fingers.”  It’s considered a congenital hand or foot difference.

Children with syndactyly may have just two digits joined together or several, and the connection may involve only the skin or include fused bones.

How common is syndactyly?

Syndactyly is one of the most common birth defects that affects babies’ hands and feet. It affects about 1 in every 2,000 to 3,000 babies. It (is) more common in boys than girls and most commonly involves the middle and ring fingers. It can also affect the toes, usually the second and third toes.

Types of syndactyly

Syndactyly is grouped into different types depending on how the fingers or toes are fused together:

• Simple syndactyly (most common type): In this form, the fingers or toes are connected by only skin and soft tissue. The bones themselves are separate and not joined together. 
• Complex syndactyly: In this form, bones, as well as the skin, are fused together. This type is more likely to limit how well the hand or foot works and usually requires more involved surgery.
• Complicated syndactyly: This is a rare form that includes extra bones, missing bones or bones that are shaped differently than usual. This type often occurs as part of a genetic condition or syndrome.

Complete vs. incomplete syndactyly

In addition, the extent of the fusion may be:

• Incomplete syndactyly: The digits are only partially connected. The amount of joining can vary from child to child.
• Complete syndactyly: This condition happens when the fingers or toes are fused all the way from the base to the fingertip or nail bed. 

What causes syndactyly?

Syndactyly usually happens during early pregnancy. (The hand starts with the all of the digits being connected). As the baby’s hands and feet form, the fingers and toes should separate. If they don’t fully split apart, this condition will happen.

There are a few possible reasons why this can happen:

• Genetics: Syndactyly can be inherited (hereditary). If a parent or an immediate relative (such as a grandparent or sibling) has it, there is a higher chance that a child might also have it.
• Syndromes: Certain health conditions that affect growth and development can also include syndactyly. These conditions include:
  • Apert syndrome
  • Poland syndrome
  • Constriction band syndrome (amniotic band syndrome)
  • Carpenter syndrome
  • Down syndrome (trisomy 21)
• Unknown causes: In many cases, the exact cause isn’t known. Something affects bone or soft tissue during a baby’s development.

Syndactyly isn’t caused by anything a parent did or didn’t do during pregnancy. It’s a part of the baby’s development. 

Signs and symptoms of syndactyly

The signs of syndactyly can vary depending on how many digits are affected and how deeply they are joined. In some children, only the skin is connected. In others, the bones and soft tissue may also be fused.

The main sign of syndactyly is that two or more fingers or toes are joined together. This can look and feel different depending on the type and severity. 

Syndactyly doesn’t usually cause pain. But it may affect how your child moves their fingers or toes.

Common signs and symptoms include:

• Webbed skin between fingers or toes
• Fingers or toes that are joined partway or all the way from base to tip
• Shared fingernails or toenails
• A wide or paddle-like shape to the hand or foot
• Limited movement in the affected fingers or toes
• Fingers or toes that are shorter or shaped differently than usual
• Trouble gripping or picking up objects

These differences can affect the way your child’s hand or foot looks, moves and functions.

How is syndactyly different from polydactyly?

Syndactyly means fingers or toes are fused together. Polydactyly means there are extra fingers or toes.

Some children can be born with both conditions, which can affect how the hand or foot looks and works.

How is syndactyly diagnosed?

Most cases of syndactyly are found when a baby is born. In some cases, it is diagnosed earlier, during a prenatal ultrasound.

To understand your child’s condition more clearly, your provider may perform a:

• Physical exam: To check how the fingers or toes move and feel
• X-ray: These show if the bones are fused
• Genetic testing: If your child has other symptoms, these tests check for related genetic syndromes or conditions

How is syndactyly treated?

If your child has syndactyly, you will be referred to a specialist, such as a pediatric hand surgeon or orthopedic surgeon, who can guide you through your options. Even if surgery isn’t needed right away, early evaluation helps plan future care.

If the joined toes don’t cause problems, your child may not need surgery. But for fingers, treatment is usually recommended to help with hand function, grip and movement.

If surgery is needed, it usually happens between the ages of 1 and 2, when the hands have grown enough for surgery but before your child has started school. The goal is to help your child use their hands or feet better and improve their overall appearance.

Your surgeon will:

• Carefully separate the fingers or toes
• Use skin grafts (extra skin) to cover the newly separated areas
• Shape the fingers or toes to improve both appearance and function

Recovery after surgery

After surgery, your child may:

• Wear a splint or cast for protection
• Attend follow-up visits
• Take part in physical or occupational therapy 
• Need more surgeries if the condition is complex

What is the outlook for syndactyly?

Most children do very well after surgery. Once the fingers and toes are separated, children usually have better movement and function. Many can do everyday activities like writing, holding toys or running and playing with little trouble.

As your child grows, the skin between the fingers can sometimes start to join again. This is known as web creep and happens when scar tissue forms in the space between the digits. If this happens, your child may need another surgery. 

With care and support, most children grow up to lead active, healthy lives. They can play sports, do crafts and keep up with their friends.

How Banner Children’s can help

We know it can feel overwhelming when your child has a condition like syndactyly. But you don’t have to face it alone. At Banner Children’s, you’ll find the care, support and answers you need to help your child grow and thrive. 

We offer:

• Expert, family-centered care designed just for kids
• Personalized treatment plans
• Surgical care from experienced pediatric hand specialists
• Support services for the entire family
• Coordination with genetics and other specialists when needed 

Find a Banner Children’s specialist near you and schedule an appointment today.