title: Does Navigation Improve Pedicle Screw Placement Accuracy? Comparison Between Navigated and Non-navigated Percutaneous and Open Fixations.
abstract: The aim of our study was to assess how a preoperative computed tomography (CT)-based navigation system affected the correctness and safety of transpedicular screw insertion, compared with standard techniques.
  
  
  
  Between January 2012 and February 2014, 203 patients underwent thoracic and lumbar fixation, with open and percutaneous techniques; 218 screws were implanted through an open navigated technique (1.0 Spine & Trauma 3d ver. 2.0 BrainLab, Feldkirchen Germany) in 43 patients; 220 screws were inserted with an open free-hand technique in 45 patients; 230 screws were implanted in 56 patients using percutaneous CT-based navigation; and 236 screws were inserted in 59 patients using a percutaneous fluoroscopy-guided technique. To our knowledge, this is the first work comparing these four different techniques. The position of each screw was evaluated on CT scan reconstruction and classified according to a four-point grading scale (grade 0: no breach, grade 1: breach < 2 mm, grade 2: breach between 2 and 4 mm; grade 3: breach >4 mm). Statistical analysis was assessed by two-way analysis of variance (ANOVA) t test, while the Fisher least significant difference (LSD) method was employed to determine statistical significance.
  
  
  
  Statistical analysis showed a significant difference in accuracy between the open CT-based navigation and the percutaneous CT-based navigation techniques (P= 0.0263) and between the open CT-based navigation and the percutaneous fluoroscopy-guided techniques (P=0.0258): a particular difference was observed in anterior misplacement between open CT-based navigation and the percutaneous fluoroscopy-guided technique (P= 0.0153).
  
  
  
  Our results confirm the advantages of the navigation technique, which ensures greater accuracy, in open as well as percutaneous procedures.
authors.affiliation: IRCCS Neuromed, Via Atinense 18, Pozzilli, IS, 86077, Italy. nch@neuromed.it.
authors.forename: Gualtiero
authors.initials: G
authors.lastname: Innocenzi
authors.affiliation: IRCCS Neuromed, Via Atinense 18, Pozzilli, IS, 86077, Italy.
authors.forename: Simona
authors.initials: S
authors.lastname: Bistazzoni
authors.affiliation: IRCCS Neuromed, Via Atinense 18, Pozzilli, IS, 86077, Italy.
authors.forename: Manuela
authors.initials: M
authors.lastname: D'Ercole
authors.affiliation: IRCCS Neuromed, Via Atinense 18, Pozzilli, IS, 86077, Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Cardarelli
authors.affiliation: IRCCS Neuromed, Via Atinense 18, Pozzilli, IS, 86077, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Ricciardi
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D005471:Fluoroscopy; D005593:Fracture Fixation, Internal / Q000379:methods*; D006801:Humans; D007405:Intervertebral Disc Displacement / Q000000981:diagnostic imaging / Q000601:surgery; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D065289:Pedicle Screws; D012008:Recurrence; D013122:Spinal Diseases / Q000000981:diagnostic imaging / Q000601:surgery*; D016103:Spinal Fractures / Q000000981:diagnostic imaging / Q000601:surgery; D013123:Spinal Fusion / Q000379:methods*; D013125:Spinal Neoplasms / Q000000981:diagnostic imaging / Q000601:surgery; D013130:Spinal Stenosis / Q000000981:diagnostic imaging / Q000601:surgery; D013168:Spondylolisthesis / Q000000981:diagnostic imaging / Q000601:surgery; D025321:Surgery, Computer-Assisted / Q000379:methods*; D013904:Thoracic Vertebrae / Q000000981:diagnostic imaging / Q000601:surgery*; D014057:Tomography, X-Ray Computed; D055815:Young Adult
keywords: Fluoroscopy-guided pedicle screw fixation; Free-hand pedicular screw fixation; Pedicle screw accuracy; Percutaneous pedicular screw fixation; Spinal CT-based navigation system