Polydactyly is a relatively common congenital hand deformity, and its incidence is still relatively high. Regarding the treatment of polydactyly many people think that it is as simple as removing one finger, this idea is certainly not true. It involves the skin, bone, tendon, joint capsule and a series of bone and joint structures. If it is simply removed, the problem is solved at that time, but the subsequent problems will be more and more troublesome. In my clinic, I have seen many children who have undergone polydactyly surgery and then come back for repair, and the most common problem reported by parents is that their child’s polydactyly has grown back after removal. Under normal circumstances, the polydactyly will not “grow” again after removal, so what is the “growth” that these parents are talking about? 1, it may be a lateral deformity, after the removal of the polydactyly, there is a lateral deformity, it looks like it “grows” again; 2, the bone is not removed cleanly, because the bone is very soft, it is difficult to see clearly in the x-ray, if not very professional surgeon in charge of the operation, it is likely that only the front end of the stump is trimmed, and part of the epiphysis remains in the operation. If the surgeon is not very professional, it is likely that only the front stump will be trimmed during the operation, and part of the epiphysis will remain inside, so the phenomenon of regrowth will occur.