Polydactyly is the most common congenital malformation of the hand and is often associated with other deformities, such as brachydactyly or syndactyly. It frequently affects the thumb and little finger. The deformity is categorized into three types:
- An external soft tissue mass without connection to bone, lacking skeletal, joint, or tendon structures.
- A fully developed finger attached to the head of the first metacarpal or to a bifurcated metacarpal head.
- A fully formed extra digit along with an additional metacarpal.
Treatment
Surgical treatment is generally performed after the age of one year, with the principle of removing the extra digit while preserving the normal one. Evaluation of finger function is performed to distinguish between the normal and extra digits. Complete removal of the extra digit is emphasized to prevent residual deformity, and careful attention is given to avoiding damage to the growth plate to ensure proper development is not impaired.