The most effective treatment for atlantoaxial dislocation is surgical treatment, with the principle of achieving reduction, reconstruction, and fusion of the atlantoaxial joint. The surgical strategies mainly include simple anterior approach, simple posterior approach, and combined anterior posterior approach. The investigators have summarized 904 cases of atlantoaxial instability or dislocation from 1998 to 2010 and preliminarily published the diagnosis and treatment strategy tree of the Third Hospital of Beijing Medical University. This strategy is divided into four types based on the severity of atlantoaxial dislocation: unstable, reversible, difficult to recover, and skeletal, and enters different surgical treatment processes. With the increase in the number of cases, accumulation of experience, and technological improvements in the past decade, spinal surgery colleagues have updated their classification diagnosis, diagnosis and treatment processes, and surgical techniques for atlantoaxial instability or dislocation.

However, the selection of treatment strategies for atlantoaxial dislocation is mostly based on the surgeon's own experience, and there is a lack of standardized, large-scale, and high-level evidence-based medical research on the safety and effectiveness of current empirical strategies. Based on this, this study intends to adopt a multicenter, retrospective, and prospective study to construct a high-quality clinical cohort of atlantoaxial dislocation, update the classification and diagnosis and treatment strategies of atlantoaxial dislocation. And conduct long-term follow-up on patients to evaluate their safety and effectiveness, guide the surgical treatment of atlantoaxial dislocation, and thus form a recognized diagnostic and treatment standard for atlantoaxial dislocation.

Inclusion Criteria:

• Patients diagnosed with atlantoaxial dislocation and treated with surgery

Exclusion Criteria:

• Disagree to participate in this study.

Patients diagnosed with atlantoaxial dislocation and treated with surgery