Syndactyly is a condition where children are born with fused or webbed fingers. About half of the children born with this condition have it in both hands. This is known as bilateral syndactyly.

There are three types of syndactyly: Simple, complex and complicated. Simple syndactyly occurs when skin and soft tissue conjoin fingers. Complex syndactyly occurs when underlying bones have joined together. Complicated syndactyly occurs when the fingers have extra bones and abnormal tendons/ligaments.

While this condition most often occurs in the fingers, syndactyly can also affect the toes.

Would you like to schedule an appointment with Orthopedics?

What are the signs and symptoms of syndactyly?

The signs differ depending on the type of syndactyly a child has:


  • Fingers conjoined by skin and soft tissue only


  • Underlying bones joined together


  • Extra bones in the affected hand/fingers
  • Abnormal tendon and/or ligament development

What causes syndactyly?

During the gestation period, a baby’s hands form in the shape of a paddle. As they continue to develop in the womb, their fingers split into separate fingers. This happens around the sixth to eighth week of pregnancy. If two or more fingers do not separate during this time, syndactyly occurs.

This condition often runs in families. About 10-40% of children with syndactyly inherit it from their parents. In some cases, syndactyly is part of a genetic syndrome (e.g., Poland syndrome or Apert syndrome).

How is syndactyly diagnosed?

Syndactyly is often diagnosed at birth. Prenatal ultrasounds can sometimes detect the condition earlier.

Sometimes an infant’s doctor will use x-rays to determine the structure of a baby’s fingers. This can help determine the type of syndactyly and course of treatment.

How is syndactyly treated?

To treat syndactyly, your child will need surgery to separate the joined fingers. They will likely have this operation when they are between 1 and 2 years old. If your child has several fingers involved, they may need more than one surgery.

Doctors at Connecticut Children’s provide skilled treatment and aftercare for syndactyly.