title: Posterolateral odontoidectomy for irreducible atlantoaxial dislocation: a technical case report.
abstract: BACKGROUND
  For the treatment of irreducible atlantoaxial dislocation (AAD), anterior decompression has been commonly used by removal of the odontoid process and fixation of the vertebral body by means of the transoral approach. Although the transoral approach has been well established, there are some disadvantages. By contrast, there have been few technical case reports of the posterolateral approach, especially for irreducible AAD.
  
  
  OBJECTIVE
  To describe a technical case report of the posterolateral approach for irreducible AAD, demonstrating the specific advantages.
  
  
  METHODS
  Technical case report.
  
  
  METHODS
  Case report.
  
  
  METHODS
  Report of postoperative symptoms.
  
  
  METHODS
  A 74-year-old woman presented with sudden left hemiparesis because of irreducible AAD. She underwent the odontoidectomy and reduction by means of the posterolateral approach. Posterior fixation with instrumentation and an iliac bone graft was performed 16 days later. The results of radiological examinations were satisfactory. The posterolateral approach takes advantage of the particular features of C1-C2 dislocation of irreducible AAD.
  
  
  CONCLUSIONS
  We suggest the possibility that the posterolateral approach is feasible and effective in most cases with irreducible AAD.
authors.affiliation: Department of Neurosurgery, Faculty of Medicine, University of Tokyo, 7-3-1 Hongo Bunkyo-ku, Tokyo 113-8655, Japan. sooya-tky@umin.ac.jp
authors.forename: Soichi
authors.initials: S
authors.lastname: Oya
authors.forename: Kazuo
authors.initials: K
authors.lastname: Tsutsumi
authors.forename: Taku
authors.initials: T
authors.lastname: Shigeno
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Takahashi
mesh_terms: D000368:Aged; D001268:Atlanto-Axial Joint / Q000473:pathology / Q000601:surgery; D019299:Decompression, Surgical; D005260:Female; D006801:Humans; D004204:Joint Dislocations / Q000473:pathology / Q000601:surgery*; D008279:Magnetic Resonance Imaging; D009809:Odontoid Process / Q000473:pathology / Q000601:surgery*; D013122:Spinal Diseases / Q000473:pathology / Q000601:surgery*; D013123:Spinal Fusion / Q000379:methods*