The conventional treatment for atlantoaxial dislocation is atlantoaxial fixation and fusion using the Goel-Harms technique, which involves a midline incision, dissection of the occipital muscle group, and is associated with disadvantages such as damage to the posterior ligament and muscle, high incidence of postoperative occipital cervical pain, and significant blood loss due to intraoperative bleeding and postoperative drainage. Since 2013, various studies have reported minimally invasive posterior atlantoaxial lateral mass joint fusion techniques through muscle spaces, but previous studies were all case reports, without sufficient reliability and controlled studies. The Department of Orthopedics at Peking University Third Hospital has been using the minimal invasive surgery-posterior atlantoaxial lateral mass joint fusion (Mis-PALF) technique for the treatment of atlantoaxial dislocation since 2015, with preliminary good clinical results. In order to further compare the advantages and disadvantages of the two surgical methods from a larger sample, a randomized controlled study is planned. The patients will be randomly divided into two groups, with the experimental group receiving the Mis-PALF surgery and the control group receiving open atlantoaxial fusion and fixation. There will be a 1-2 year follow-up to compare the safety and effectiveness of the two surgical methods for the treatment of atlantoaxial dislocation.