Abstract: Objective：To initially evaluate the effect of the lumbar peek cage combining with posterior fixation as the treatment of atlantoaxial dislocation. Methods：Between June 2015 to Feburary 2016, 4 patients with atlantoaxial instability accepted the surgery of posterior fixation and atlantoaxial joint distraction. The lumbar peek cage was used to distract the C1-C2 facet joint at the first time during this procedure. Pre- and post-operative VAS, JOA, cervical deformity and bone fusion were calculated and analyzed prospectively. Results：All of four patients have finished a twelve months follow up. The VAS and JOA at pre-operative and 12 months follow up was 8±0.82, 13±5.42 and 1±0.82, 16±1.41，respectively. The VAS and JOA after surgery were better than those before surgery. There were no intraoperative or postoperative vascular, neurological, or infection-related complications. The 3D CT at 12 months follow up showed that all of four patients achieved solid fusion. Conclusions：Compared with the existing distraction methods, the use of lumbar peek cage not only has no influence on the operational effect, but also decreases the complication and the deficiency when it is used to treat the atlantoaxial joint distraction. Besides those advantages, the use of peek cage is also easy to spread.