What is the most common congenital deformity affecting the second and third digits?

• A. Syndactyly
• B. Polydactyly
• C. Clinodactyly
• D. Brachydactyly

Answer: (A)

Syndactyly is the fusion or webbing between adjacent digits, and it is the most common congenital hand deformity. During development, the tissues between forming fingers should undergo programmed cell death to separate them; when that process is incomplete, the digits remain joined. This often involves the middle fingers, the second and third digits, presenting as soft-tissue webbing that can be limited to skin or include bone. Clinically, it’s managed by surgical separation to restore independent motion, usually in infancy, with reconstruction as needed for skin coverage.

The other conditions describe different problems: an extra digit (polydactyly), a finger that curves abnormally due to bone in the finger (clinodactyly), or unusually short fingers (brachydactyly). For the specific question about the most common deformity affecting the second and third digits, syndactyly is the best fit.