title: [Anterior odontoid screw fixation using intra-operative cone-beam computed tomography and navigation].
abstract: OBJECTIVE
  The purpose of this study was to asses the value of intraoperative cone-beam CT (O-arm) and stereotactic navigation for the insertion of anterior odontoid screws.
  
  
  METHODS
  this was a retrospective review of patients receiving surgical treatment for traumatic odontoid fractures during a period of 18 months. Procedures were guided with O-arm assistance in all cases. The screw position was verified with an intraoperative CT scan. Intraoperative and clinical parameters were evaluated. Odontoid fracture fusion was assessed on postoperative CT scans obtained at 3 and 6 months' follow-up
  
  
  RESULTS
  Five patients were included in this series; 4 patients (80%) were male. Mean age was 63.6 years (range 35-83 years). All fractures were acute type ii odontoid fractures. The mean operative time was 116minutes (range 60-160minutes). Successful screw placement, judged by intraoperative computed tomography, was attained in all 5 patients (100%). The average preoperative and postoperative times were 8.6 (range 2-22 days) and 4.2 days (range 3-7 days) respectively. No neurological deterioration occurred after surgery. The rate of bone fusion was 80% (4/5).
  
  
  CONCLUSIONS
  Although this initial study evaluated a small number of patients, anterior odontoid screw fixation utilizing the O-arm appears to be safe and accurate. This system allows immediate CT imaging in the operating room to verify screw position.
authors.affiliation: Servicio de Neurocirugía, Complexo Hospitalario Universitario de Ourense, Ourense, España. Electronic address: juliancastrocastro@yahoo.es.
authors.forename: Julián
authors.initials: J
authors.lastname: Castro-Castro
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001863:Bone Screws; D054893:Cone-Beam Computed Tomography; D005260:Female; D005593:Fracture Fixation, Internal / Q000379:methods*; D050723:Fractures, Bone / Q000601:surgery*; D006801:Humans; D007432:Intraoperative Period; D008297:Male; D008875:Middle Aged; D009809:Odontoid Process / Q000293:injuries* / Q000601:surgery*; D012189:Retrospective Studies; D025321:Surgery, Computer-Assisted; D014057:Tomography, X-Ray Computed
keywords: Anterior screw fixation; Cirugía guiada por imagen; Cone-beam computed tmography; Fijación con tornillo anterior; Fractura de odontoides; Image guided surgery; Odontoid fracture; Tomografía computarizada de haz cónico