Polydactyly is one of the most common congenital malformations. Some redundant fingers are inherited, for example, the redundant fingers of middle finger and little finger are autosomal dominant genetic malformations. The fourth finger, namely the ring finger, middle finger and little finger, has its own unique manifestations. Complex deformities such as mirror hand (ulnar hand) and five-fingered hand also belong to redundant finger deformities, and repeated deformities can be divided into three types: radial (thumb side), medial and ulnar (little finger side).

Step 2 refer to each other

Syndactyly is also common, which can be divided into complete syndactyly and partial syndactyly. Only soft tissue closure can also be called simple syndactyly. Complex syndactyly with bony connection. Syndactyly is more common between 3 and 4 fingers, and can also be seen in Apert syndrome (premature closure of cranial suture with syndactyly of hand or foot), banded malformation and Poland syndrome (absence and syndactyly of pectoralis major).

Step 3 bend your fingers

Bending refers to bending deformation pointing to frontal or sagittal plane, and there are local bone deformation besides bending fingers. Many sick children have different systemic diseases. Bending finger is a common bending finger, which can be divided into infant type and adolescent type. Puberty develops slowly from 12 to 14 years old, which is more common in women.

4. Internal deviation finger

The medial deviation refers to the inclination of the distal segment of the little finger to the radial side. It can mutate normally, has no dysfunction and does not need treatment. Some sick children have serious deformities and need osteotomy to correct them. As many as 25~79% of Down's syndrome has finger tilt, and many congenital syndromes also have this kind of finger deformation.

5. Short fingers

Short finger refers to short bone or metacarpal bone, which is autosomal inheritance and can be complicated with Polish syndrome and Silver syndrome. Finger lengthening is often unsuccessful.