title: Revision cervical spine surgery using transarticular or pedicle screws under a computer-assisted image-guidance system.
abstract: BACKGROUND
  The exact insertion of a cervical screw is technically demanding, especially when normal anatomic landmarks have been obscured and are difficult to identify, such as in revision surgery. The purpose of this study was to evaluate the efficacy of an image-guidance system to aid placement of transarticular and pedicular screws for revision cervical spine surgery.
  
  
  METHODS
  Ten patients with recurrent myelopathy, including seven with cerebral palsy, two with a giant cell tumor, and one with rheumatoid arthritis, underwent computer-aided reconstruction surgery. The authors used a frameless stereotactic image-guidance system with simultaneous fluoroscopy. Postoperative computed tomography was used to determine the accuracy of the screw placement.
  
  
  RESULTS
  There were no neurovascular complications and no correction loss. All patients showed solid bony union. All four C1/2 transarticular screws were exactly placed inside the pedicles. Of 47 pedicular screws, 11 showed a slight breach of the cortex. When a reference arc could not be attached to the relevant vertebra, the rate of cortical perforation of screws was high (5/10; 50%) compared with the rate when a reference arc was attached to the relevant vertebra (6/37; 16%).
  
  
  CONCLUSIONS
  Although more advanced technology is hopeful, a computer-assisted image-guidance system with simultaneous fluoroscopy is useful for aiding revision surgery to achieve rigid fixation and ensure safety.
authors.affiliation: Department of Orthopaedic Surgery, Tokyo University School of Medicine, Bunkyo-ku, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Seichi
authors.forename: Katsushi
authors.initials: K
authors.lastname: Takeshita
authors.forename: Susumu
authors.initials: S
authors.lastname: Nakajima
authors.forename: Toru
authors.initials: T
authors.lastname: Akune
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kawaguchi
authors.forename: Kozo
authors.initials: K
authors.lastname: Nakamura
mesh_terms: D001863:Bone Screws; D002547:Cerebral Palsy / Q000601:surgery*; D005260:Female; D006801:Humans; D007593:Joint Instability / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D012086:Reoperation; D013118:Spinal Cord Diseases / Q000601:surgery*; D013123:Spinal Fusion; D025321:Surgery, Computer-Assisted