title: Computer-assisted surgery for dynamic hip screw, using Surgix, a novel intraoperative guiding system.
abstract: BACKGROUND
  We present Surgix, a new computer-assisted surgery system (CASS). This system uses image analysis technology in order to measure three-dimensional (3D) distances, visualize implant templates and view the guided trajectory on standard fluoroscopy. Our purpose was to compare surgery results and technique with and without the Surgix CASS.
  
  
  METHODS
  The study included 61 dynamic hip screw (DHS) procedures. The Surgix system was used in 41 procedures. We compared the number of guide wire insertion trials and the time needed for each trial, the number of X-ray pulses, tip-apex index, nine-quadrant position and shaft-neck angle.
  
  
  RESULTS
  The procedures were carried out by experienced users (> or = five operations, using the system) and had a first-trial guide wire insertion success rate of 77.8%, compared to a rate of 10% for the control group (p = 0.001) and fewer insertion trials (1.33 vs. 3.05, respectively; p = 0.001). The mean number of fluoroscopy pulses was 41.5% lower for the experienced group than for the control (17.6 vs. 30.1; p = 0.009). There were no significant differences in tip-apex distance, favourable quadrant screw placement or neck-shaft angle.
  
  
  CONCLUSIONS
  The results of this study demonstrate that the Surgix CASS significantly improves the accuracy of hardware positioning and reduces radiation exposure time, thus enhancing patient outcome.
authors.affiliation: Department of Orthopaedic Surgery, Sheba Medical Centre, Tel Hashomer, Israel. amirherm@bezeqint.net
authors.forename: Amir
authors.initials: A
authors.lastname: Herman
authors.forename: Assaf
authors.initials: A
authors.lastname: Dekel
authors.forename: Itamar B
authors.initials: IB
authors.lastname: Botser
authors.forename: Ely L
authors.initials: EL
authors.lastname: Steinberg
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001863:Bone Screws; D004867:Equipment Design; D005260:Female; D005264:Femoral Fractures; D005471:Fluoroscopy / Q000295:instrumentation; D005593:Fracture Fixation, Internal / Q000295:instrumentation*; D006620:Hip Fractures / Q000000981:diagnostic imaging / Q000601:surgery*; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000295:instrumentation; D016268:Internal Fixators; D008297:Male; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000295:instrumentation; D025321:Surgery, Computer-Assisted / Q000295:instrumentation / Q000379:methods