Syndactyly, a common congenital hand anomaly, 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. There may be skin and soft tissue fusion
or bony fusion.