The incidence of polydactyly and syndactyly is relatively high among congenital hand deformities in newborns, and the surgeries are usually not too complicated and the results are usually good. However, there is one hand deformity that is less prevalent and rarely recognized, which leads to a lack of awareness among parents and delays in getting the right surgery for their child. The most obvious symptom of this rare congenital hand deformity is the lack of metacarpal bone in the thumb, which is connected to the metacarpal bone only by a loose skin tube. If the child cannot use his thumb, he will try to use his index finger and thumb to pinch things in an attempt to replace the thumb function, which will inevitably lead to deformation of the finger body over time, and the longer the time spent pinching things, the more serious the deformation will be, which will have an impact on the child’s hand function and appearance. The more time passes, the more severe the deformity will become, affecting the function and appearance of the child’s hand, which we do not want to see. Early surgery will allow the thumb to function more smoothly and will be beneficial to the physical and mental health of the child.