The follow-up was 4 years and 1 months on average(2 years and 3 months to 7 years and 6 months),12 cases were treated with double segment decompression and Keystone method of bone graft.

• 随访2年3个月~7年6个月,平均4年1个月,17例患者确诊为颈椎后凸畸形;