What is Syndactyly?
Syndactyly, one of the most common congenital hand anomalies, is an abnormal connection of fingers or toes to one another—the digits are “webbed,” and have failed to separate normally during development. It most commonly involves the middle and ring fingers. In about 50% of cases, both hands are involved. Syndactyly may occur alone, or with other anomalies as part of a syndrome.
Helping Hands Brochures:

Are there different forms and different levels of severity with syndactyly?
Yes. The classifications of syndactyly correspond to the conditions different types and degrees of complexity. Syndactyly can be classified in the following ways:
- Incomplete: the webbing or joining doesnt 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.
+
Does syndactyly cause my baby any pain?Typically, syndactyly is not painful. However, in some very severe cases, in which the nails might grow into the joined fingertips, minor infections and wounds can cause some discomfort.
+
Who gets syndactyly?Syndactyly can occur in any newborn infant. Overall, syndactyly occurs in approximately one out of 2500 newborns. In up to approximately 40% of cases, there is a family history of syndactyly. If syndactyly occurs alone, it is inherited as an autosomal dominant condition; that is, the children of an affected individual will have a 50% chance of having syndactyly. However, syndactyly is not the same from one generation to the next, and can be more or less severe than in the affected parents. Syndactyly is more common in Caucasians than in other ethnicities, and affects boys twice as often as girls.
+
What causes syndactyly?When the hands and feet are developing in the womb, they start out as flat “paddles” that then normally separate into five digits. Syndactyly occurs when there is a failure of this separation process. This may be caused by a genetic abnormality or by environmental influences.
+
What are the main issues related to syndactyly?The primary issue in syndactyly is function of the hand and digits. Syndactyly causes limitation of function, because the involved digits cannot move completely independently. In very severe cases, with multiple digits involved in complex syndactyly, there can be problems with infections and skin breakdown.
+
Are there other problems that occur commonly with syndactyly?Some children with syndactyly will have other congenital abnormalities or syndromes. Syndactyly may occur as part of several different syndromes.
+
What is the treatment for babies with syndactyly?While every patient is treated individually, with treatment plans made specifically for him or her, some generalizations are possible. Syndactyly is treated surgically, with an operation that separates the digits using skin from the digits and, sometimes skin grafts from the arm or lower abdomen to cover the separated fingers. When the small finger or thumb is involved, this operation is done at about six months of age, to avoid distortion of the adjacent ring or index finger with growth, since the thumb and small finger are shorter than their neighboring digits. Otherwise, syndactyly release is often performed at an older age, ranging from 12 months to 3 years. Before this age, the incidence of wound healing complications and skin graft failures is significantly higher. In special cases with very complex syndactyly—or complicated syndactyly–such as in Apert’s syndrome, surgery may begin earlier, and multiple procedures may be required in a staged sequence to achieve separation of all the digits.
+
What sorts of specialists will be involved in my baby’s care?At the very least, your child will be treated by the hand surgeon and a certified hand therapist. In addition, a geneticist and developmental pediatrician are usually involved in the care of babies with Syndactyly.
+
Other Common Hand AbnormalitiesPolydactyly literally means “extra digits.” There may be an extra thumb, small finger, or, less commonly, an extra digit in the central part of the hand. Polydactyly is one of the most common congenital hand anomalies.