title: Redirecting pedicle screws: a revision spinal fusion strategy using three-dimensional image guidance.
abstract: BACKGROUND
  Pedicle screws are a preferred method for spinal fixation because of their three-column support and rigid posterior stabilization. The purpose of this study was to evaluate the outcome of patients requiring pedicle screw redirection, and to describe a technique using cone-beam computed tomography (cbCT).
  
  
  METHODS
  A retrospective review of 30 patients undergoing revision spinal fusion with redirection of pedicle screws was performed. Fifty pedicle screws were redirected in these patients using cbCT-based 3D image guidance. They were graded pre- and post-operatively using an established grading system.
  
  
  RESULTS
  No complications occurred in this study as a result of redirection. No pedicle breach was noted in all of the redirected pedicle screws.
  
  
  CONCLUSIONS
  Redirection of misplaced pedicle screws using cbCT-based 3D image guidance seems to be safe and accurate in our experience. Further studies are needed to establish its safety, accuracy, fusion rate, and clinical outcome compared with other methods. Copyright © 2016 John Wiley & Sons, Ltd.
authors.affiliation: Department of Neurosurgery, Mayo Clinic, Jacksonville, Florida, USA.
authors.forename: Jang W
authors.initials: JW
authors.lastname: Yoon
authors.affiliation: St. Vincent's Spine and Brain Institute, Jacksonville, Florida, USA.
authors.forename: Eric W
authors.initials: EW
authors.lastname: Nottmeier
authors.affiliation: Department of Neurosurgery, Mayo Clinic, Jacksonville, Florida, USA.|Department of Neurosurgery, Mayo Clinic Health System, Waycross, Georgia.
authors.forename: Gazanfar
authors.initials: G
authors.lastname: Rahmathulla
authors.affiliation: Department of Radiology, Mayo Clinic, Jacksonville, Florida, USA.
authors.forename: Douglas S
authors.initials: DS
authors.lastname: Fenton
authors.affiliation: Department of Neurosurgery, Mayo Clinic, Jacksonville, Florida, USA.
authors.forename: Stephen M
authors.initials: SM
authors.lastname: Pirris
mesh_terms: D054893:Cone-Beam Computed Tomography; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D007432:Intraoperative Period; D065289:Pedicle Screws; D015203:Reproducibility of Results; D012189:Retrospective Studies; D013123:Spinal Fusion / Q000379:methods*; D025321:Surgery, Computer-Assisted; D016896:Treatment Outcome
keywords: cone beam CT; image guidance; intraoperative navigation; pedicle screw; revision; spine fusion