What is syndactyly?

If your child has syndactyly, it means that the fingers or toes are webbed or joined and that the condition was present at birth. Syndactyly is a fairly common congenital defect that often runs in families, affecting about 1 out of every 2,500 babies. Caucasians are more likely than African-Americans or Asians and to have syndactyly, and boys are more likely to have it than girls.

Syndactyly affects both hands (bilateral) about 50 percent of the time and most often occurs between the middle and ring fingers. It also can affect a child’s toes as well as fingers; however, the condition poses more complex challenges for hand-and-finger use than for foot-and-toe use.


What are the different forms of syndactyly?

Comparison of Incomplete Syndactyly and Complete Syndactyly.

The classifications of syndactyly correspond to the condition’s different types and degrees of complexity. Syndactyly can be classified in the following ways:

  • incomplete: the webbing or joining doesn’t extend all the way to the fingertips
  • complete: the webbing or joining extends all the way to the fingertips
  • simple: the fingers are joined only by soft tissue
  • complex: the fingers are joined by bone or bony cartilage, as well as soft tissue, in a side-by-side fashion
  • complicated: the fingers are joined by bone or bony cartilage, as well as soft tissue, in a fashion other than side-by-side — such as with abnormally shaped, extra or missing bones

What are the causes of syndactyly?

During normal embryonic development (while the baby is still in the womb), the hand initially forms in the shape of a paddle; then — at about the sixth or seventh week of gestation — splits into separate fingers. Syndactyly results if there’s an irregularity in this process: The fingers fail to divide normally (failure of differentiation) and the result is a webbed hand.

Some cases of syndactyly occur in isolation and sporadically — meaning by themselves, for no identifiable genetic reason. In about 10 to 40 percent of cases, the condition occurs as an inherited trait. And in some cases, syndactyly is an accompanying defect in a genetic syndrome, such as Poland syndrome, Apert syndrome, or Holt-Oram syndrome.

Syndactyly is visible at birth. It may also be visible in utero by fetal ultrasound.

How we care for syndactyly

The Orthopedic Center’s Hand and Orthopedic Upper Extremity Program and our Department of Plastic and Oral Surgery's Hand and Reconstructive Microsurgery Program have treated thousands of babies and children with syndactyly and other hand problems. We are experienced treating conditions that range from routine to highly complex, and can provide your child with expert diagnosis, treatment, and care. We also offer the benefits of some of the most advanced clinical and scientific research in the world.

Our Orthopedic Center is nationally known as the preeminent center for the care of children and young adults with a wide range of developmental, congenital, neuromuscular, sports related, traumatic, and post-traumatic problems of the musculoskeletal system.

Our Department of Plastic and Oral Surgery is one of the largest and most experienced pediatric plastic and oral surgery centers anywhere in the world. We provide comprehensive care and treatment for a wide variety of congenital and acquired conditions, including hand deformities.