title: Computer-assisted surgery and intraoperative three-dimensional imaging for screw placement in different pelvic regions.
abstract: BACKGROUND
  The purpose of this study was to assess the feasibility and accuracy of computer-assisted surgery (CAS) for screw placement in different pelvic regions using intraoperative three-dimensional (3D) imaging and to evaluate the influence of surgeons' experience with such a system on procedure time, radiation time, radiation dose, and misplacement rate.
  
  
  METHODS
  Experimental study in a human cadaveric model (n=5) for percutaneous screw placement in the anterior column of the acetabulum, the posterior pelvic ring (S1, S2), and the superior pubic ramus via 3D fluoroscopic navigated procedure. Accuracy of screw placement was assessed by 3D image intensifier, including the reconstruction of multiplanar images and by computer tomography (CT) scan. Influence of surgeons' experience was assessed by direct comparison of a low- and high-volume surgeon using the same technical setting.
  
  
  RESULTS
  In 100% of all procedures, intraoperative Iso-C3D image analysis was sufficient to confirm a correct screw placement. The postoperative CT scan revealed no further screw misplacement. However, for a correct supraacetabular screw placement, the intraoperative 3D scan was essential. In this group, the 3D scan showed screw misplacement in three cases. Procedure time for all indications and screw failure rate were significantly lower for the higher experienced surgeon.
  
  
  CONCLUSIONS
  The 3D fluoroscopic navigated procedure in pelvic surgery seems to be a useful tool for all surgeons and especially for less experienced ones. Furthermore, the intraoperative reconstruction of multiplanar 3D images allows a secure control of implant positioning.
authors: Department of Trauma, Hand and Reconstructive Surgery, and Institute of Anatomy, University Medical Center Hamburg-Eppendorf, Martinistr 52, D-20246 Hamburg, Germany. lgrosste@uke.de
authors: Lars
authors: L
authors: Grossterlinden
authors: Jakob
authors: J
authors: Nuechtern
authors: Philipp G C
authors: PG
authors: Begemann
authors: Ina
authors: I
authors: Fuhrhop
authors: Jan P
authors: JP
authors: Petersen
authors: Andreas
authors: A
authors: Ruecker
authors: Martin
authors: M
authors: Rupprecht
authors: Wolfgang
authors: W
authors: Lehmann
authors: Udo
authors: U
authors: Schumacher
authors: Johannes M
authors: JM
authors: Rueger
authors: Daniel
authors: D
authors: Briem