title: Posterior distraction reduction and occipitocervical fixation for the treatment of basilar invagination and atlantoaxial dislocation.
abstract: OBJECTIVE
  To introduce a novel distraction technique for the treatment of basilar invagination (BI) and atlantoaxial dislocation (AAD) via a posterior-only approach.
  
  
  METHODS
  Twenty-one consecutive patients with BI and AAD who underwent posterior distraction reduction and occipitocervical fixation between January 2009 and June 2013 were enrolled in the present study. This novel distraction technique included two steps. First, the distraction between the occipitocervical junction of the rod (OCJR) and the occipital screws was performed to achieve horizontal and partial vertical reduction. Secondly, the distraction was performed between the C2 screws and OCJR to achieve complete vertical reduction. The pre- and postoperative JOA score, the extent of reduction, the fusion status, and the complications were recorded and analyzed.
  
  
  RESULTS
  The mean follow-up was 18.3 months with a range of 10-32 months. No patient incurred neurovascular injury during surgery. The mean JOA score at the last follow-up (15.4) showed significant improvement (P<0.01) compared with the pre-operative parameters (11.2). Complete horizontal reduction was achieved in 18 patients (85.7%), and complete vertical reduction was achieved in 17 patients (80.9%). The rest patients are all received greater than 50% horizontal and vertical reduction. Solid fusion was achieved in 20 patients (95.2%). Mild dysphagia was observed in two patients. One patient suffered from postoperative fever and pulmonary infection.
  
  
  CONCLUSIONS
  This novel distraction technique may provide satisfactory reduction via a posterior-only approach without exposure of the C1/2 facet joint. Therefore, it is a safe and effective method for the treatment of BI with AAD.
authors.affiliation: Department of Orthopaedic Surgery, West China Hospital, Sichuan University, No. 37 Guo Xue Xiang, Chengdu, Sichuan 610041, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Meng
authors.affiliation: Department of Orthopaedic Surgery, West China Hospital, Sichuan University, No. 37 Guo Xue Xiang, Chengdu, Sichuan 610041, China.
authors.forename: Hua
authors.initials: H
authors.lastname: Chen
authors.affiliation: Department of Orthopaedic Surgery, West China Hospital, Sichuan University, No. 37 Guo Xue Xiang, Chengdu, Sichuan 610041, China.
authors.forename: Jigang
authors.initials: J
authors.lastname: Lou
authors.affiliation: Department of Orthopaedic Surgery, West China Hospital, Sichuan University, No. 37 Guo Xue Xiang, Chengdu, Sichuan 610041, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Rong
authors.affiliation: Department of Orthopaedic Surgery, West China Hospital, Sichuan University, No. 37 Guo Xue Xiang, Chengdu, Sichuan 610041, China.
authors.forename: Beiyu
authors.initials: B
authors.lastname: Wang
authors.affiliation: Department of Orthopaedic Surgery, West China Hospital, Sichuan University, No. 37 Guo Xue Xiang, Chengdu, Sichuan 610041, China.
authors.forename: Yuxiao
authors.initials: Y
authors.lastname: Deng
authors.affiliation: Department of Orthopaedic Surgery, West China Hospital, Sichuan University, No. 37 Guo Xue Xiang, Chengdu, Sichuan 610041, China.
authors.forename: Chen
authors.initials: C
authors.lastname: Ding
authors.affiliation: Operation Room, West China Hospital, Sichuan University, No. 37 Guo Xue Xiang, Chengdu, Sichuan 610041, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Hong
authors.affiliation: Department of Orthopaedic Surgery, West China Hospital, Sichuan University, No. 37 Guo Xue Xiang, Chengdu, Sichuan 610041, China. Electronic address: dr.liuhao6304@hotmail.com.
authors.forename: Hao
authors.initials: H
authors.lastname: Liu
mesh_terms: D000328:Adult; D000368:Aged; D001268:Atlanto-Axial Joint / Q000601:surgery*; D001863:Bone Screws; D002574:Cervical Vertebrae / Q000601:surgery*; D019299:Decompression, Surgical / Q000379:methods; D005260:Female; D006801:Humans; D004204:Joint Dislocations / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D019838:Neck Injuries / Q000601:surgery; D013123:Spinal Fusion / Q000379:methods; D016896:Treatment Outcome; D021801:Zygapophyseal Joint / Q000601:surgery*
keywords: Atlantoaxial dislocation; Basilar invagination; Craniovertebral junction; Distraction; Reduction