The mother of a child said that her child was found to have an underdeveloped right thumb at birth, different from normal children, and was diagnosed as a floating finger at the local hospital, when the child was too young to have surgery. What should I do? Because of the lack of function of the thumb, the child’s thumb cannot be cocked and cannot do the nod of approval, so it is necessary to improve the function and shape of the thumb through surgery. We mainly use hemi-metacarpal bone graft reconstruction (SMRT floating thumb reconstruction) to treat the floating thumb, which is the most advanced surgical procedure for treating floating thumb. The hemi-metacarpal bone graft reconstruction takes a part of the bone from the child’s second metacarpal bone to reconstruct the first metacarpal bone. The whole operation is performed only on the child’s hand, and the rest of the child’s body parts will not be affected in any way, and some effects caused by thumbing and metatarsal reconstruction of the index finger are also avoided. Parents do not need to worry, the child can undergo hemi-metacarpal bone graft reconstruction between 6 months and 1 year old in good health condition, and the growth and development of the second metacarpal bone will not be affected after the operation. After surgery, parents should help their children to recover and exercise according to our instructions. We have found that many children who come to our clinic for review have a better recovery of thumb function if parents pay attention to and actively exercise their children. Generally, after the surgery and recovery exercises, the child’s thumb function and shape will be improved to a certain extent, and he/she will be able to do palmar, grasp, pinch and other movements, and the thumb will be able to be cocked and do some praise movements.