title: Percutaneous lumbar pedicle screw placement aided by computer-assisted fluoroscopy-based navigation: perioperative results of a prospective, comparative, multicenter study.
abstract: METHODS
  Institutional review board-approved, prospective, multicenter, comparative study.
  
  
  OBJECTIVE
  To assess the accuracy and utility of a computer-assisted fluoroscopic navigation method for percutaneous placement of lumbar pedicle screws compared with conventional fluoroscopic placement.
  
  
  BACKGROUND
  Recent reports indicate that cortical breaches during percutaneous pedicle screw placement can exceed 15%. Computed tomography (CT)- and fluoroscopy-based navigation systems may facilitate increased placement accuracy with reduced radiation exposure and operative times.
  
  
  METHODS
  Patients were alternately assigned to either the Guidance or Control group. The Guidance group underwent lumbar pedicle screw placement using the oblique visualization technique and computer-assisted fluoroscopic navigation. The Control group underwent lumbar pedicle screw placement per standard percutaneous technique aided by fluoroscopy alone. Baseline demographics, visual analog scale (VAS) pain scores, and American Spinal Injury Association scores were obtained preoperatively and in the immediate postoperative period. Fluoroscopy times and guidewire insertion times were recorded intraoperatively. All postoperative CT scans were reviewed by an independent spine surgeon to grade screw placement accuracy.
  
  
  RESULTS
  Forty-two patients (210 screws) were assigned to the Guidance group and 34 patients (152 screws) were assigned to the Control group. Use of Guidance resulted in reduced average fluoroscopy usage per pedicle [6.6 sec (SD = 5.1) vs. 9.6 sec (SD 6.2), P < 0.001] and more expedient placement of guidewires per pedicle [3.65 min (SD = 2.31) vs. 4.43 min (SD = 2.56), P = 0.003]. The Guidance group experienced less than half of the breach rate of the Control group (3.0% vs. 7.2%, P = 0.055) and reduced breach magnitudes. None of the breaches resulted in a corresponding neurological deficit or required revision. All patient-reported outcomes were significantly improved after surgery and there were no significant differences in average postoperative VAS scores between treatment groups.
  
  
  CONCLUSIONS
  Use of Guidance reduces fluoroscopy and insertion times with increased accuracy compared with conventional fluoroscopic methods of percutaneous pedicle screw insertion.
authors.affiliation: Northwestern Neurosurgical Associates, 7447 West Talcott Avenue, Chicago, IL 60631, USA. b-yang1@md.northwestern.edu
authors.forename: Benson P
authors.initials: BP
authors.lastname: Yang
authors.forename: Melvin M
authors.initials: MM
authors.lastname: Wahl
authors.forename: Cary S
authors.initials: CS
authors.lastname: Idler
mesh_terms: D000328:Adult; D000368:Aged; D001863:Bone Screws; D005260:Female; D005471:Fluoroscopy / Q000379:methods*; D006801:Humans; D008159:Lumbar Vertebrae / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D010147:Pain Measurement; D011184:Postoperative Period; D011446:Prospective Studies; D013122:Spinal Diseases / Q000601:surgery*; D025321:Surgery, Computer-Assisted / Q000379:methods*; D016896:Treatment Outcome