Finger polydactyly.

Polydactyly is one of the most common congenital differences. Duplications of the index finger, central rays, and small digit each have unique characteristics and associations. Complex anomalies such as the mirror hand and pentadactyly represent specialized forms of polydactyly. The goal of reconstructing a functional hand is met by appreciating the anatomic variations and systemic implications, then employing the challenging technical and intellectual concepts described.