title: Cervical pedicle screw placement using intraoperative computed tomography imaging with a mobile scanner gantry.
abstract: A multi-detector computed tomography (CT) imaging system with a mobile scanner gantry in the operating room can provide intraoperative reconstructed images with a high resolution. We devised a technique for cervical pedicle screw (CPS) placement using the mobile CT system and evaluated the accuracy of this technique.
  
  
  
  Forty-eight patients who underwent cervical fixation using CPSs were prospectively enrolled in this study. Initial pedicle probing was performed approximately to the depth of the posterior aspect of the vertebral body using fluoroscopic lateral view, and a marking pin was put in place. Intraoperative CT images were obtained to confirm whether the position of the marking pin was accurate. After adequate modification of the trajectory was performed, an appropriately sized CPS was inserted. The accuracy of the CPS was evaluated using postoperative reconstructed CT images, and compared with a historical control group of 22 patients (CPS insertion using only fluoroscopy).
  
  
  
  A total of 193 CPSs were inserted. Intraoperative CT images demonstrated that 12.4 % of the initial probings were not accurate, and modification of the trajectory was required. On postoperative CT, 92.7 % of the CPSs were found to be placed accurately: the accuracy was significantly higher than the control group (80.9 %). In the cases using intraoperative CT images, only 1.0 % of the screws were judged to show grade 2 screw misplacement; no neurovascular complications associated with screw placement were observed.
  
  
  
  The technique of CPS placement using mobile CT was shown to be safe and effective in preventing catastrophic complications associated with CPS insertion.
authors.affiliation: Department of Orthopaedic Surgery, Graduate School, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8519, Japan. yoshii.orth@tmd.ac.jp.|Section of Regenerative Therapeutics for Spine and Spinal Cord, Graduate School, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8519, Japan. yoshii.orth@tmd.ac.jp.
authors.forename: Toshitaka
authors.initials: T
authors.lastname: Yoshii
authors.affiliation: Department of Orthopaedic Surgery, Graduate School, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8519, Japan.|Section of Regenerative Therapeutics for Spine and Spinal Cord, Graduate School, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8519, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Hirai
authors.affiliation: Department of Orthopaedic Surgery, Graduate School, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8519, Japan.
authors.forename: Kenichiro
authors.initials: K
authors.lastname: Sakai
authors.affiliation: Department of Orthopaedic Surgery, Graduate School, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8519, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Inose
authors.affiliation: Department of Orthopaedic Surgery, Graduate School, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8519, Japan.
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Kato
authors.affiliation: Department of Orthopaedic Surgery, Graduate School, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8519, Japan.|Section of Regenerative Therapeutics for Spine and Spinal Cord, Graduate School, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8519, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Okawa
mesh_terms: D002574:Cervical Vertebrae / Q000601:surgery*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D019637:Orthopedic Procedures / Q000295:instrumentation / Q000379:methods; D065289:Pedicle Screws; D025321:Surgery, Computer-Assisted / Q000379:methods*; D014057:Tomography, X-Ray Computed / Q000379:methods*
keywords: Accuracy; Cervical pedicle screw; Complications; Intraoperative CT; Learning curve