title: [Clinical effect of posterior atlanto axial vertebra internal fixation for treatment of instability of occipitocervical].
abstract: OBJECTIVE
  To explore radiographic results and clinical effects of posterior atlanto axial vertebra internal fixation in treating instability of occipitocervical.
  
  
  METHODS
  The clinical data of 155 patients with instability of occipitocervical treated by posterior atlanto axial vertebra internal fixation were respectively analyzed from September 2005 to January 2011. There were 68 males and 87 females, ranging in age from 6 to 75 years old with an average of 45.6 years old. Of them, 53 cases were fresh odontoid fractures(Aderson type II C), 30 cases were os odontoideum, 20 cases were old odontoid fractures, 18 cases were unstable atlas fractures, 12 cases were atlanto axial rotatory dislocation, 11 cases were atlanto axial dislocation after rheumatoid arthritis, and 11 cases were basilar invagination. Radiographic results were evaluated in terms of atlas pedicle screw fixation, bone healing and bone graft fusion. Clinical effect evaluation included relief of pain in the occipital-cervical region by VAS score and JOA score.
  
  
  RESULTS
  Totally 300 screws were set through atlas pedicle screw fixation in 150 patients. Five patients receivde hook fixation. Postoperative CT showed ideal nailing were 275 (91.7%),acceptable nailing were 14 (4.7%) and unacceptable nailing were 11 (3.6%). All patients were followed up, and the duration ranged from 16 to 40 months with an average of 25.4 months. The fresh fractures healed and 140 cases got bone graft fusion. Preoperative VAS and JOA score were respectively improved from (7.2 +/- 1.1), (7.3 +/- 2.4) to (3.2 +/- 1.1), (13.3 +/- 2.4) at the latest follow-up.
  
  
  CONCLUSIONS
  Posterior atlanto axial vertebra internal fixation in treating instability of occipitocervical can effectively recover physiological curvature of cervical, provide mechanical stability, and obtain good clinical effect. For the young patients who require further activity, posterior fixation and non-fusion technology is a good choose, which can avoid bone graft.
authors.affiliation: Department of Orthopaedics ,the Second Affiliated Hospital of Zhejiang University of Medicine, Hangzhou 310009, Zhejiang, China. bertchen@sohu.com
authors.forename: Qiang-Hua
authors.initials: QH
authors.lastname: Zhang
authors.forename: Qi-Xin
authors.initials: QX
authors.lastname: Chen
authors.forename: Fang-Cai
authors.initials: FC
authors.lastname: Li
authors.forename: Gang
authors.initials: G
authors.lastname: Chen
authors.forename: Bin
authors.initials: B
authors.lastname: Han
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001268:Atlanto-Axial Joint / Q000601:surgery*; D001863:Bone Screws; D001270:Cervical Atlas / Q000601:surgery*; D002648:Child; D005260:Female; D005593:Fracture Fixation, Internal; D006801:Humans; D016268:Internal Fixators; D007593:Joint Instability / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D016896:Treatment Outcome; D055815:Young Adult