The floating thumb is actually a floating thumb. In the past, the floating thumb could not be preserved and could only be removed for bunionization, after which the child would only have four fingers forever, which is unacceptable to many parents. Therefore, we now start from the preservation of five fingers, remodeling a thumb for the baby’s affected hand, in order to achieve the goal of thumb preservation. We mainly use the technique of hemi-metacarpal bone graft reconstruction, taking part of the bone from the second metacarpal bone of the affected hand to reconstruct the first metacarpal bone, the whole surgery is divided into two phases, the first phase of the bone removal, so that the thumb has a better shape, and then do the second phase of the surgery to rebuild the function of the thumb, so that the fingers can be moved, and after the two phases of the surgery, the child can begin to function exercise. Hemi-metacarpal bone graft reconstruction is usually done when the child is about 6 months to 1 year old. This is the time when the child’s thumb function is being established, and parents usually have their child undergo the surgery at this time in order to allow the thumb function to be established more smoothly. Parents can give them some square and round toys to make the child realize that the thumb can be used, and he will get more and more used to using the thumb, so that the thumb can become more and more flexible. This is a benign cycle, and as long as all aspects of the operation work well together, the results will be more satisfactory after the operation.