In the past, the common treatment for floating thumb was to remove the thumb and move the index finger to the thumb position to use it as a thumb, although the operation can also achieve the purpose of letting the child have a thumb function. However, some parents find it too cruel and unacceptable to have their child’s thumb removed, leaving them with only four fingers. In fact, floating thumbs can be preserved. There are two main methods, metatarsal bone reconstruction and hemi-metacarpal bone graft reconstruction techniques, and the biggest difference between them is the location of the bone extraction. Metatarsal bone reconstruction is to reconstruct the first metacarpal bone from the foot, there is a certain degree of bone resorption and necrosis, and will have a certain impact on the foot, the child needs three months after the operation can not go down to the ground, can only lie down or sit, the parents in the care will be more cumbersome. Semi-metacarpal bone grafting is a procedure that uses a portion of the second metacarpal bone of the affected hand to rebuild the first metacarpal bone, which has a much lower chance of bone resorption and necrosis. The entire surgery is performed on the hand only, without moving other parts of the body, and it is easy to take care of the hand after the surgery by paying more attention to the hand. After the surgery, the child can perform functional exercises, such as writing, holding chopsticks, screwing bottle caps, etc., which basically meets the needs of daily life.