title: Image-guided placement of occipitocervical instrumentation using a reference arc attached to the headholder.
abstract: OBJECTIVE
  To develop a safe and accurate method of image-guided placement of instrumentation in the upper cervical spine and occiput in which the reference arc is fixed to the headholder.
  
  
  METHODS
  The authors describe a technique for placing screws at the occipital, C1, and C2 levels using 3-dimensional image guidance in which the reference arc is fixed to the headholder. Technical details are discussed as well as modifications to the technique to maximize navigation accuracy and decrease the need for re-registration. One of 2 paired systems, the BrainLAB Vector Vision system (BrainLAB Inc., Westchester, IL) used in conjunction with the Arcadis Orbic Isocentric C-arm (Siemens Medical Solutions, Erlangen, Germany) or the Stealth Treon system (Medtronic, Littleton, MA) paired with the O-arm (Medtronic), was used for image guidance in this study. A total of 18 patients had 82 screws placed at the occipital, C1, or C2 level using this technique. An independent radiologist interpreted postoperative computed tomographic scans of these patients and graded the screws for bony breach.
  
  
  RESULTS
  No complications resulted from the use of image guidance or from the placement of instrumentation. Postoperative computed tomography revealed 1 screw with a minimal breach of the outer lamina of C2. Another screw was replaced intraoperatively secondary to a minimal bony breach. No other bony breach occurred.
  
  
  CONCLUSIONS
  This technique allows safe and accurate placement of instrumentation in the posterior occipitocervical junction using 3-dimensional image guidance in which the reference arc is attached to the headholder.
authors.affiliation: Department of Neurosurgery, Mayo Clinic, Jacksonville, Florida 32224, USA. Nottmeier.eric@mayo.edu
authors.forename: Eric W
authors.initials: EW
authors.lastname: Nottmeier
authors.forename: Phillip M
authors.initials: PM
authors.lastname: Young
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001269:Atlanto-Occipital Joint / Q000033:anatomy & histology / Q000473:pathology / Q000601:surgery*; D001368:Axis, Cervical Vertebra / Q000033:anatomy & histology / Q000473:pathology / Q000601:surgery; D001863:Bone Screws / Q000592:standards; D001270:Cervical Atlas / Q000033:anatomy & histology / Q000473:pathology / Q000601:surgery; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000295:instrumentation / Q000379:methods; D021621:Imaging, Three-Dimensional / Q000295:instrumentation / Q000379:methods*; D016268:Internal Fixators / Q000592:standards*; D007593:Joint Instability / Q000473:pathology / Q000601:surgery; D008297:Male; D008875:Middle Aged; D038361:Neuronavigation / Q000295:instrumentation / Q000379:methods*; D009777:Occipital Bone / Q000033:anatomy & histology / Q000473:pathology / Q000601:surgery; D011183:Postoperative Complications / Q000209:etiology / Q000517:prevention & control; D013122:Spinal Diseases / Q000473:pathology / Q000601:surgery; D013123:Spinal Fusion / Q000295:instrumentation / Q000379:methods*; D013238:Stereotaxic Techniques / Q000295:instrumentation; D013525:Surgical Instruments / Q000592:standards; D014057:Tomography, X-Ray Computed / Q000295:instrumentation / Q000379:methods*; D016896:Treatment Outcome