The following methods are used to correct the XO-leg: 1. Osteotomy and internal fixation. In adults, if the deformity of the joint is due to osteoarthritis or trauma to the knee joint, osteotomy with internal fixation of the plate can be performed to correct the XO leg. 2. Joint replacement. For elderly people with osteoarthrosis or deformities, joint replacement can be performed to correct the XO-leg, which can play a role in correcting the deformity and treating the arthritis at the same time, killing two birds with one stone. If the XO-leg in children or adolescents is caused by the imbalance of epiphyseal development, epiphyseal plates can be fixed to make the epiphyseal development on both sides balanced so that the correction can be carried out.