Is simply cutting off an extra finger (toe) on a hand or foot the answer? The answer is no. For surgical treatment of polydactyly, in addition to removing the extra finger, it is more important to reconstruct the function of the finger and restore the appearance of the finger, of which reconstructing the function of the finger is the most critical. The timing and manner of surgery differs for different types of polydactyly. Dr. Xin Wang, deputy chief of pediatric orthopedics at the Capital Institute of Pediatrics, was invited to explain the timing of surgery for polydactyly. Dr. Xin Wang said, according to the different anatomical structures of polydactyly, there are many types of medical subtypes, which can be simply divided into three categories: 1, soft tissue polydactyly (redundant finger, floating finger): only a narrow dermatome wrapped with vascular nerves, and normal fingers are connected, polydactyly is only soft tissue, no joints, tendons and other tissues; 2, simple polydactyly: polydactyly contains finger bones, tendons and vascular nerve bundles, and normal finger bones have bony The normal finger bones are connected or jointed, but the normal finger bone development is basically normal, which is equal to an extra finger with defective function; 3, compound polydactyly: the polydactyly is a real repetitive growth, not only contains finger bones, tendons, etc., partly including the repetitive growth of the metacarpal bone, the normal finger bones are poorly developed, the articular surface is deformed, and it is often not easy to distinguish which one is the polydactyly, and often requires X-ray to differentiate. For soft tissue polydactyly, since there is no bony deformity, only a narrow dermatome wrapped around the vascular nerve and connected to the normal finger, it can usually be surgically removed after the baby is born. For simple polydactyly, i.e., polydactyly with bony deformity, such as two fingers sharing one finger joint, in addition to removal of the polydactyly, functional reconstruction of the fingers, such as displacement of tendons, reconstruction of lateral collateral ligaments and abduction function, and osteotomy of the phalanges and metacarpals, is also required. Because the bones of infants and children are still developing, this surgery is usually done when they are about 1 year old in order to better distinguish between the normal and deformed structures of the fingers. However, the surgery should not be done too late. If you break the bad branch of a tree when it is small, the remaining one will grow stronger and straighter. However, if you don’t break it when you are young, it will affect the development of the main trunk when you grow up. In other words, early surgery to remove the extra fingers will facilitate better development of the preserved fingers. For the treatment of compound polydactyly, Dr. Xin Wang recommends two surgical procedures: soft tissue surgery at the age of 1 year, which means excision of the polydactyly, osteotomy of the phalanges and metacarpals, tendon transposition, and reconstruction of the lateral collateral ligaments and abduction function. The deformity of the metacarpophalangeal or interphalangeal joints is improved by intraoperative capsular tightening. Because the bones of infants and young children still have developmental potential, postoperative improvement of the deformity of the joint through massage, wearing orthopedic braces (palmar brace – made of engineering plastic that changes shape when exposed to temperature, forming a shape suitable for the child’s own situation to fix the metacarpophalangeal or interphalangeal joint), etc. usually has a more satisfactory result. If, after conservative treatment, a part of the metacarpophalangeal joint and interphalangeal joint deformity still remains, an osteotomy orthopedic surgery can be performed at the age of about 3 years, with internal fixation with a Kirschner pin after the osteotomy and external plaster fixation for 3 – 4 weeks. Why do we need to wait until the baby is 3 years old to perform osteotomy? The main reason is that there are two major problems with osteotomies in younger children: on the one hand, it is easy to injure the epiphyseal plate of the child and affect the development of the finger; on the other hand, osteotomy before the right age may increase the chance of intraoperative injury. As for whether the finger will be deformed again after correction, Dr. Wang Xin said that this phenomenon was indeed found in patients transferred from other hospitals. The main reason for this is that the surgeon simply removed the extra finger during surgery and did not completely remove the extra bony protrusions from the metacarpal or phalanges. The remaining bony prominence contains epiphyseal plates, which will continue to grow and eventually grow a bony bump again. Therefore, it is important to completely remove the bony prominence and epiphyseal plate during the surgery and to do a good job of repairing the joint in order to ensure that the finger will not be deformed again after the surgery.