Atlantoaxial subluxation is a pathological change in which the atlantoaxial and pivotal (first and second cervical vertebrae) osteoarticular surfaces lose their normal alignment and joint dysfunction and/or nerve compression occurs as a result of congenital malformation, trauma, degeneration, tumor, infection inflammation and surgery. Atlantoaxial subluxation is a serious disease. Due to forward or backward atlantoaxial dislocation and compression of the upper cervical medulla, the patient may suddenly develop rigid paresis or even respiratory muscle paralysis and die due to minor head and neck injuries or excessive cervical flexion and extension. The common clinical manifestations of atlantoaxial subluxation are as follows: 1. Symptoms of the subluxation itself: the symptoms of the atlantoaxial subluxation itself include pain in the neck and collar, sometimes radiating to the shoulder, spasm of the neck muscles, and impaired head movement. 2. Symptoms of surrounding tissues and organs: difficulty in swallowing, obvious posterior protrusion of the spinous process of the cardinal spine and often pressure pain. In case of unilateral anterior dislocation, the head posture is abnormal, with the head and neck deviating to the side of dislocation, while the jaw is turned to the opposite side. 3. Spinal cord compression symptoms: Patients may have symptoms of upper cervical cord compression after minor trauma to the head and neck, such as transient pain or numbness in the extremities. When the dislocation is aggravated, different degrees of rigid paralysis of the limbs can appear, accompanied by urinary and fecal dysfunction. Atlantoaxial dislocation may be caused by minor head and neck injury or cervical hyperflexion and compression of the upper cervical medulla, and the patient may suddenly develop rigid paresis or even respiratory muscle paralysis and die.