title: Operative management for atlantoaxial instability in case of bilateral high-riding vertebral artery.
abstract: BACKGROUND
  In case of atlantoaxial instability dorsal C1-C2 screw fixation is the most appropriate procedure to get immediate and sufficient three-point fixation. However, this method cannot be performed in bilateral high-riding vertebral arteries because of high risk of VA injury.
  
  
  METHODS
  In a 66-year-old woman who presented with neck pain due to atlantoaxial instability bilateral high-riding VAs were detected in CT. To avoid VA injury a dorsal stabilization procedure with a hook-rod system and interspinous autologous iliac crest graft was performed. The intra- and postoperative courses had no complications and the hook-rod construction clinically led to immediate postoperative stability. After 24 months the patient was painfree.
  
  
  CONCLUSIONS
  In case of atlantoaxial instability and bilateral high-riding VAs dorsal C1-C2 fixation procedure with a hook-rod system and interspinous bone grafting seems to be an appropriate alternative surgical technique and can get immediate and clinically sufficient stability with no risk of VA injury.
authors.affiliation: Orthopedic Department, Hannover Medical School, Clinic II Annastift, Anna-von-Borries-Str. 1-7, 30625 Hannover, Germany. daentzer@tiscali.de
authors.forename: Dorothea
authors.initials: D
authors.lastname: Daentzer
mesh_terms: D000368:Aged; D001268:Atlanto-Axial Joint / Q000601:surgery*; D016025:Bone Transplantation; D005260:Female; D005593:Fracture Fixation, Internal / Q000379:methods*; D006801:Humans; D016268:Internal Fixators; D007593:Joint Instability / Q000601:surgery*; D011859:Radiography; D014711:Vertebral Artery / Q000002:abnormalities / Q000000981:diagnostic imaging*