Atlantoaxial dislocation is caused by loss of normal alignment of the atlantoaxial joints due to neck trauma, cervical spine developmental deformity or other factors, and can be life-threatening in severe cases. The atlantoaxial joint is the so-called joint formed by the connection of the first and second vertebrae of the cervical spine. It consists of 3 articular structures, i.e., 2 lateral atlantoaxial joints and 1 medial atlantoaxial joint, which are held in place by ligaments. The atlantoaxial joint can be dislocated following a fracture of the atlantoaxial odontoid process during neck trauma, or it can be dislocated due to trauma resulting in a simple anterior atlantoaxial dislocation. Fracture-dislocations or simple dislocations caused by trauma can result in life-threatening spinal cord injury in severe cases. In addition, atlantoaxial joint instability can also result in dislocation due to atlantoaxial developmental abnormalities, such as dentoaxial hypoplasia. In addition, atlantoaxial dislocation can also be caused by atlantoaxial and cardinal vertebrae due to osteoporosis of the vertebral body, tuberculosis infection and other bone destructive. Atlantoaxial dislocations require prompt hospitalization and regular treatment because of the high risk of spinal cord injury.