Floating thumb, also known as floating thumb and dermatomes of the fingers, is a very specific type of thumb dysplasia in which the thumb is attached to the palm of the hand by a very small, thin skin tibia, with no bones or tendons attached to the palm, hence the name floating thumb.
Floater’s thumb is a congenital hand deformity for which no clear cause has been found, and most doctors speculate that it may be related to a family history of the condition, medications taken during pregnancy, or infections. The clinical manifestation is that the root of the thumb is relatively thin, only the skin tube is connected, there is no metacarpal bone, and the function of the thumb is completely lost.
There are three clinical treatments: the first is called index finger bunionization, in which the index finger is sacrificed to build a brand new thumb; the second is hemimetatarsal reconstruction, in which half of the metatarsal bone is transplanted to rebuild the thumb; and the third is hemimetacarpal grafting, in which a portion of the second metacarpal bone is taken to rebuild the thumb.
Currently, the third method is mostly used, and with later rehabilitation, most of the children can regain the function of the thumb.