X/O leg refers to X-shaped leg, or knee valgus, and O-shaped leg, or knee entropion, respectively. It is possible for patients with valgus and entropion to become taller after correction. X-shaped legs and O-shaped legs are mainly caused by genetic factors, calcium deficiency, and various diseases. Therefore, in childhood, if X-shape legs or O-shape legs are found, it is recommended to correct them in time, and take calcium and vitamin D supplements in time to promote calcium absorption, so as to avoid affecting height development. For patients with mild to moderate knee valgus, braces can be used to correct it, which usually need to be worn for more than one year. For severe knee valgus, osteotomy should be performed at the obvious part of the deformity, and the deformity should be immobilized with plaster and corrected with internal rotation after the operation. For knee valgus, supracondylar femoral osteotomy should be performed according to the site of deformity in order to correct the deformity, and brace immobilization and rehabilitation therapy should be adopted after surgery to consolidate the effect of surgery. X-shaped leg and O-shaped leg patients should follow the doctor’s instructions and actively cooperate with the doctor’s treatment, after active correction, the limb will be appropriately lengthened, so it is possible to become taller after the correction of X-shaped leg and O-shaped leg.