Atlantoaxial subluxation is a pathological change in which the osteoarticular surfaces of the atlantoaxial and pivotal spine (first and second cervical vertebrae) lose their normal alignment and joint dysfunction and/or nerve compression occurs as a result of congenital malformation, trauma, degeneration, tumor, infection and inflammation, and surgery. Clinical manifestations include: 1. occipital and cervical pain. 2. Slanting neck and limited neck movement. 3.Superior spinal cord damage may manifest as generalized muscle tension, unstable or weak hand grip, easy to break water cups and rice bowls; weakness in walking and easy to fall; weakness in urination and defecation; muscle atrophy of limbs; in severe cases, generalized paralysis may occur, even life-threatening. 4. Vertigo, tinnitus, blurred vision, chest tightness, palpitations and elevated blood pressure. 5.In combination with Arnold-Chiari malformation with cerebellar tonsillar herniation, there may be symptoms such as generalized muscle weakness and easy to fall. Atlantoaxial subluxation may be caused by slight head and neck injury or cervical hyperflexion and compression of the upper cervical medulla, and the patient may suddenly develop rigid paralysis, or even respiratory muscle paralysis and die. The aim of treatment for atlantoaxial dislocation is to relieve spinal cord compression, stabilize the cervical joints, and prevent further dislocation. Occipital cervical fixation is often chosen as the surgical approach, but the surgical risks are large. On the one hand, the vertebral artery, spinal cord and nerve roots are easily damaged when internal fixation screws are driven in, resulting in posterior circulation ischemia, spinal cord injury and nerve root injury, and even life-threatening paralysis and respiratory impairment; on the other hand, dentate resetting is difficult and does not resolve spinal cord entrapment. How to accurately perform internal fixation screw implantation and resolve the compression on the spinal cord is the key to the surgery.