title: Stereotactic CT-guided percutaneous stabilization of posterior pelvic ring fractures: a preclinical cadaver study.
abstract: OBJECTIVE
  To determine the accuracy of frameless stereotactic computed tomographic (CT)-guided wire placement for percutaneous fixation of posterior pelvic ring fractures in human cadavers.
  
  
  METHODS
  Four intact human cadavers were fixated in a double-vacuum immobilization system. A 2.5-mm helical CT dataset was obtained and transferred to the three-dimensional (3D) navigation system. In every specimen, two paths on each side (total number, 16) were defined on multiplanar reconstructions of the 3D CT datasets, simulating fixation of the iliosacral joint. An aiming device was adjusted according to the plan, and a 2.5-mm pin was advanced through the aiming device to the precalculated target point. To determine the accuracy of pin placement, a control CT scan was co-registered to the planning CT scan (with the planned trajectories). The distance between the planned and achieved positions of the pins (3D accuracy) was calculated in millimeters.
  
  
  RESULTS
  The mean 3D accuracy was 1.84 mm +/- 0.9 (standard deviation) at the bone entrance point and 2.5 mm +/- 1.2 at the target, as determined with image fusion between the planning CT scan and the control CT scan with the pins in place.
  
  
  CONCLUSIONS
  The described technique enables accurate placement of pins in the pelvis and may be useful for percutaneous orthopedic procedures.
authors.affiliation: Interdisciplinary Stereotactic Intervention and Planning Laboratory (SIP-Lab) at the Department of Radiology, Medical University Innsbruck, Anichstrasse 35, Innsbruck, Austria.
authors.forename: Reto J
authors.initials: RJ
authors.lastname: Bale
authors.forename: Peter
authors.initials: P
authors.lastname: Kovacs
authors.forename: Bahman
authors.initials: B
authors.lastname: Dolati
authors.forename: Christoph
authors.initials: C
authors.lastname: Hinterleithner
authors.forename: Ralf E
authors.initials: RE
authors.lastname: Rosenberger
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001858:Bone Nails; D001863:Bone Screws; D002102:Cadaver; D003198:Computer Simulation; D005260:Female; D005593:Fracture Fixation, Internal / Q000295:instrumentation / Q000379:methods*; D050723:Fractures, Bone / Q000000981:diagnostic imaging* / Q000601:surgery*; D006801:Humans; D021621:Imaging, Three-Dimensional; D008297:Male; D019060:Minimally Invasive Surgical Procedures; D010384:Pelvic Bones / Q000000981:diagnostic imaging* / Q000601:surgery*; D011857:Radiographic Image Interpretation, Computer-Assisted; D015641:Radiography, Interventional; D015203:Reproducibility of Results; D012446:Sacroiliac Joint / Q000000981:diagnostic imaging / Q000601:surgery; D025321:Surgery, Computer-Assisted; D036542:Tomography, Spiral Computed