title: Accuracy of percutaneous lumbar pedicle screw placement using the oblique or "owl's-eye" view and novel guidance technology.
abstract: OBJECTIVE
  This study was conducted to assess the in vivo safety and accuracy of percutaneous lumbar pedicle screw placement using the owl's-eye view of the pedicle axis and a new guidance technology system that facilitates orientation of the C-arm into the appropriate fluoroscopic view and the pedicle cannulation tool in the corresponding trajectory.
  
  
  METHODS
  A total of 326 percutaneous pedicle screws were placed from L-3 to S-1 in 85 consecutive adult patients. Placement was performed using simple coaxial imaging of the pedicle with the owl's-eye fluoroscopic view. NeuroVision, a new guidance system using accelerometer technology, helped align the C-arm trajectory into the owl's-eye view and the cannulation tool in the same trajectory. Postoperative fine-cut CT scans were acquired to assess screw position. Medical records were reviewed for complications.
  
  
  RESULTS
  Five of 326 screws breached a pedicle cortex—all breaches were less than 2 mm—for an accuracy rate of 98.47%. Five screws violated an adjacent facet joint. All were at the S-1 superior facet and included in a fusion. No screw violated an adjacent mobile facet or disc space. There were no cases of new or worsening neurological symptoms or deficits for an overall clinical accuracy of 100%.
  
  
  CONCLUSIONS
  The owl's-eye technique of coaxial pedicle imaging with the C-arm fluoroscopy, facilitated by NeuroVision, is a safe and accurate means by which to place percutaneous pedicle screws for degenerative conditions of the lumbar spine. This is the largest series reported to use the oblique or owl's-eye projection for percutaneous pedicle screw insertion. The accuracy of percutaneous screw insertion with this technique meets or exceeds that of other reported clinical series or techniques.
authors.affiliation: Orthopaedic Specialists of North Carolina, Wake Forest, North Carolina, USA.
authors.forename: Cary
authors.initials: C
authors.lastname: Idler
authors.forename: Kevin W
authors.initials: KW
authors.lastname: Rolfe
authors.forename: Josef E
authors.initials: JE
authors.lastname: Gorek
mesh_terms: D000328:Adult; D001863:Bone Screws; D005260:Female; D005471:Fluoroscopy; D006801:Humans; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging* / Q000601:surgery*; D008297:Male; D038361:Neuronavigation / Q000295:instrumentation / Q000379:methods* / Q000592:standards; D019637:Orthopedic Procedures / Q000009:adverse effects / Q000379:methods* / Q000592:standards; D011857:Radiographic Image Interpretation, Computer-Assisted; D015203:Reproducibility of Results; D013122:Spinal Diseases / Q000601:surgery*; D025321:Surgery, Computer-Assisted / Q000379:methods* / Q000592:standards; D014057:Tomography, X-Ray Computed