title: Use of intraoperative isocentric C-arm 3D fluoroscopy for sextant percutaneous pedicle screw placement: case report and review of the literature.
abstract: BACKGROUND
  Three-dimensional (3D) fluoroscopy-based image guidance system using an isocentric C-arm (Iso-C) fluoroscope was shown to be as effective as computed tomography-based systems in guiding the accurate percutaneous placement of lumbar pedicle screws in cadavers. To date, however, no description is available of the intraoperative use of 3D fluoroscopy to guide lumbar pedicle screw placement in an actual spinal fusion procedure.
  
  
  OBJECTIVE
  We report a case in which isocentric 3D fluoroscopic images, along with image-guidance software, were used to guide the placement of percutaneous pedicle screws for fusion in a patient with degenerative spondylolisthesis.
  
  
  METHODS
  Operating room of a large academic medical center during the placement of percutaneous pedicle screws in a patient with degenerative spondylolisthesis.
  
  
  METHODS
  A percutaneous dynamic reference array was attached to the L3 spinous process. A satisfactory image set was obtained and automatically registered. The L4 and L5 pedicles were localized, and pedicle holes were then cannulated, drilled and tapped. A screw was then inserted using the Sextant system for percutaneous pedicle screws. In this manner, bilateral pedicle screws were inserted into the L4-L5 pedicles. All steps of pedicle cannulation were performed under Iso-C 3D image guidance.
  
  
  RESULTS
  A postoperative computed tomography scan showed accurate placement of all pedicle screws. The patient experienced an improvement in leg pain with no new neurologic deficits.
  
  
  CONCLUSIONS
  The present case is the first case to demonstrate the intraoperative use of a 3D fluoroscopy-based image-guidance system for accurate navigation during lumbar pedicle screw placement.
authors.affiliation: Department of Neurological Surgery, University of California, San Francisco, 505 Parnassus Avenue, M-779, San Francisco, CA 94143-0112, USA.
authors.forename: Frank L
authors.initials: FL
authors.lastname: Acosta
authors.forename: Timothy L
authors.initials: TL
authors.lastname: Thompson
authors.forename: Stacey
authors.initials: S
authors.lastname: Campbell
authors.forename: Philip R
authors.initials: PR
authors.lastname: Weinstein
authors.forename: Christopher P
authors.initials: CP
authors.lastname: Ames
mesh_terms: D001863:Bone Screws; D005260:Female; D005471:Fluoroscopy / Q000379:methods; D005593:Fracture Fixation, Internal; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods; D008159:Lumbar Vertebrae / Q000601:surgery*; D008875:Middle Aged; D016343:Monitoring, Intraoperative / Q000379:methods*; D013168:Spondylolisthesis / Q000601:surgery*; D025321:Surgery, Computer-Assisted / Q000379:methods*