A parent of a child in the clinic said that they went to the hospital when the child was very young and the doctor diagnosed it as a floating finger and suggested that the child should undergo an index finger thumb surgery when the child was older, and they had been waiting for it. They chose to use hemi-metacarpal bone graft reconstruction (SMRT floating thumb reconstruction) to treat the child’s floating finger. First of all, doctors in Europe and the United States used to choose to remove the floating thumb directly after thumb thumb reconstruction. The purpose of thumb thumb reconstruction is to sacrifice the index finger to build a new thumb, the advantages of which are that the surgery is relatively simple, the baby recovers faster, the hand is permanently four fingers, and the difference between the appearance and the normal hand is more obvious. At the same time, the Chinese cultural tradition makes it difficult for many parents to accept the reduction of one finger in their child. Then we used metacarpal reconstruction to treat the child’s floating finger. The first method used was hemi-metatarsal reconstruction, which is a traditional surgical method that involves transplanting half of the third or fourth metatarsal (longitudinal) from the child’s foot into the hand to reconstruct the first metacarpal and the first carpometacarpal joint, which preserves the five fingers but also leads to some effects, so we have been thinking about the possibility of performing the surgery directly on the hand. In order to solve the problems caused by thumbing and metatarsal reconstruction of the index finger, after years of research and clinical practice, we realized the method of treating the child’s floating finger with hemi-metacarpal bone graft reconstruction, which is performed only on the child’s hand, and a part of the bone is taken from the second metacarpal to reconstruct the first metacarpal, which will not affect other body parts of the child while preserving the five fingers, and the growth and development of the second metacarpal will not be affected after the operation, and the thumb Many parents and children are satisfied with the function and appearance of the thumb compared to the pre-operative period. Compared to index thumb and hemi-metatarsal reconstruction, hemi-metacarpal bone graft reconstruction for floating fingers has multiple advantages, and more and more parents are more willing to let their children undergo this state-of-the-art surgical procedure.