We are all familiar with polydactyly, both in our lives and in movies. As for floating thumb, the probability of seeing this congenital malformation is lower than that of polydactyly, and the probability of them happening to a baby at the same time is even lower, but in the hand surgery clinic, it is not uncommon to see babies with both. Earlier this month, I had a 4-year-old boy with both polydactyly and floating thumb in my clinic. He had polydactyly in his right hand and a floating thumb in his left hand, which was a complicated situation overall. During the interview, the mother and father told me that they had been to major hospitals across the country to treat their child’s hands, but most of the opinions they received were to remove the polydactyly from the right hand and to reconstruct the thumb or metatarsal bone in the left hand. However, they were not very willing to bunionize the left index finger and did not want to take the bone from the foot for treatment. By chance, after seeing my popular science video, they came to Wuhan from Hangzhou the next day. What is the best treatment? After looking at the film, combined with the results of the interview, it was found that the thumb of this little boy’s right hand was not functioning very well and the treatment of both hands was quite difficult. On the one hand, the function of the little boy’s right thumb should be taken into consideration, and the function of the thumb should be improved while removing the extra finger to improve its stability; on the other hand, a hemimelia reconstruction is recommended to reconstruct the first metacarpal bone and function of the child’s left hand. Can both hands be operated on at the same time? Many parents and friends have mentioned the question of whether the right and left hands can be operated on at the same time. In fact, there is no conflict between simultaneous surgery on both hands. The first surgery can be done simultaneously with the reconstruction of the first metacarpal bone, and the second surgery can be performed on the left hand about 4-6 months after the first surgery to complete the functional reconstruction. Post-operative functional exercises are important Post-operative functional exercises are important to restore the function of the hand and this step can only be left to the parents, while the surgeon can only provide advice on exercises. Due to the age of the child, they will be afraid of functional exercises for both hands and will not cooperate with their parents to complete the functional exercises. In short, for this type of children, if there is no physical problem, the treatment should be started at about 6 months of age, the earlier the treatment, the better the results will be.