title: Computer-navigated iliosacral screw insertion reduces malposition rate and radiation exposure.
abstract: Insertion of percutaneous iliosacral screws with fluoroscopic guidance is associated with a relatively high screw malposition rate and long radiation exposure. We asked whether radiation exposure was reduced and screw position improved in patients having percutaneous iliosacral screw insertion using computer-assisted navigation compared with patients having conventional fluoroscopic screw placement. We inserted 26 screws in 24 patients using the navigation system and 35 screws in 32 patients using the conventional fluoroscopic technique. Two subgroups were analyzed, one in which only one iliosacral screw was placed and another with additional use of an external fixator. We determined screw positions by computed tomography and compared operation time, radiation exposure, and screw position. We observed no difference in operative times. Radiation exposure was reduced for the patients and operating room personnel with computer assistance. The postoperative computed tomography scan showed better screw position and fewer malpositioned screws in the three-dimensional navigated groups. Computer navigation reduced malposition rate and radiation exposure.
  
  
  METHODS
  Level II, therapeutic study.
authors.affiliation: Department of Orthopaedic and Trauma Surgery, University of Freiburg Medical Center, Hugstetter Strasse 55, 79106 Freiburg, Germany. jzwingmann@freenet.de
authors.forename: Jörn
authors.initials: J
authors.lastname: Zwingmann
authors.forename: Gerhard
authors.initials: G
authors.lastname: Konrad
authors.forename: Elmar
authors.initials: E
authors.lastname: Kotter
authors.forename: Norbert P
authors.initials: NP
authors.lastname: Südkamp
authors.forename: Michael
authors.initials: M
authors.lastname: Oberst
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001863:Bone Screws; D005260:Female; D005471:Fluoroscopy; D050723:Fractures, Bone / Q000000981:diagnostic imaging* / Q000601:surgery*; D006801:Humans; D007593:Joint Instability / Q000000981:diagnostic imaging / Q000601:surgery; D008297:Male; D008875:Middle Aged; D010388:Pelvis / Q000000981:diagnostic imaging / Q000293:injuries / Q000601:surgery; D011446:Prospective Studies; D011829:Radiation Dosage; D012446:Sacroiliac Joint / Q000000981:diagnostic imaging / Q000293:injuries* / Q000601:surgery*; D025321:Surgery, Computer-Assisted / Q000379:methods*; D055815:Young Adult