title: Clinical assessment of percutaneous lumbar pedicle screw placement using theO-arm multidimensional surgical imaging system.
abstract: BACKGROUND
  Increasing popularity of minimally invasive surgery for lumbar fusion has led to dependence upon intraoperative fluoroscopy for pedicle screw placement, because limited muscle dissection does not expose the bony anatomy necessary for traditional, freehand techniques nor for registration steps in image-guidance techniques. This has raised concerns about cumulative radiation exposure for both surgeon and operating room staff. The recent introduction of the O-arm Multidimensional Surgical Imaging System allows for percutaneous placement of pedicle screws, but there is limited clinical experience with the technique and data examining its accuracy.
  
  
  OBJECTIVE
  We present the first large clinical series of percutaneous screw placement using navigation of O-arm imaging and compare the results with the fluoroscopy-guided method.
  
  
  METHODS
  A retrospective review of a 24-month period identified patients undergoing minimally invasive lumbar interbody fusion. The O-arm was introduced in the middle of this period and was used for all subsequent patients. Accuracy of screw placement was assessed by examination of axial computed tomography or O-arm scans.
  
  
  RESULTS
  The fluoroscopy group included 141 screws in 42 patients, and the O-arm group included 205 screws in 52 patients. The perforation rate was 12.8% in the fluoroscopy group and 3% in the O-arm group (P < .001). Single-level O-arm procedures took a mean 200 (153-241) minutes, whereas fluoroscopy took 221 (178-302) minutes (P < .03).
  
  
  CONCLUSIONS
  Percutaneous pedicle screw placement with the O-arm Multidimensional Intraoperative Imaging System is a safe and effective technique and provided improved overall accuracy and reduced operative time compared with conventional fluoroscopic techniques.
authors.affiliation: Department of Neurosurgery, Montefiore Medical Center, Bronx, New York 10467, USA. jkhmd@yahoo.com
authors.forename: John K
authors.initials: JK
authors.lastname: Houten
authors.forename: Rani
authors.initials: R
authors.lastname: Nasser
authors.forename: Nrupen
authors.initials: N
authors.lastname: Baxi
mesh_terms: D001863:Bone Screws; D005471:Fluoroscopy / Q000379:methods; D006801:Humans; D008159:Lumbar Vertebrae / Q000601:surgery*; D019060:Minimally Invasive Surgical Procedures / Q000379:methods*; D038361:Neuronavigation / Q000379:methods*; D012189:Retrospective Studies; D013123:Spinal Fusion / Q000379:methods*