The following methods can be used to improve the XO-leg: first, if in children or adolescents, it is often caused by the imbalance of epiphysis development, surgical treatment of epiphyseal plates can be performed to make the epiphysis development balanced, so as to correct the XO-leg. Second, osteotomy, in adults, XO-leg is often due to trauma to the joint or deformity caused by osteoarthritis, osteotomy can be performed, and the plate can be used to fix the osteotomy, which can correct XO-leg. Third, joint replacement, especially in elderly patients with osteoarthritis, can be used to improve the deformity of XO-leg and treat osteoarthritis at the same time, which can play a two-fold role.