Polydactyly is a congenital physical malformation in humans having supernumarary fingers or toes. The extra digit is usually a small piece of soft tissue that can be easily removed. The digit is rarely function and often has no sensation. Polydactyly requires an operation to remove the digits, normally at an early age.

Syndactyly is the most common congenital malformation of the limbs and occurs when fingers fail to separate into individual appendages. This separation usually should occur during the sixth or eighth week of embryologic development. This malformation requires surgical intervention and can be performed as early as five or six months of age.