title: Assessment of two 3-D fluoroscopic systems for articular fracture reduction: a cadaver study.
abstract: OBJECTIVE
  The most commonly used imaging device for assessment of fracture reduction is the two-dimensional X-ray fluoroscope. Two recently introduced 3D fluoroscopic devices, the Siremobil ISO-C3D (Siemens) and the C-InSight (Mazor Surgical Technologies), enable the surgeon to obtain spatial information for the assessment of articular reduction and hardware placement. The purpose of this study was to assess the reliability and accuracy of these two 3D fluoroscopic systems in measuring articular reduction in a cadaveric tibial plateau fracture.
  
  
  METHODS
  Six cadaveric knee specimens were osteotomized at the lateral tibial plateau and fixed with a maximal articular step-off of 0, 1, 2.5, 5 and 7.5 mm. Each specimen was scanned 10 times with two 3D fluoroscopes, the Siremobil ISO-C3D and the C-InSight. The resulting images were reformatted and interpreted for articular displacements at four different locations at the plateau level and were compared with high-resolution CT scans by an independent observer.
  
  
  RESULTS
  For the non-displaced fracture, no displacement (mean < 0.1 mm) was observed in either modality. The mean scanning time for the ISO-C3D was 2 min, while each C-InSight scan took 20 s. The readings at four different points along the malreduced fractures were similar for most measurements with either of the two modalities. The C-InSight readings were less accurate than those of the ISO-C3D, relative to the CT scan, but most errors were within clinically acceptable limits (< 2 mm) and used less radiation.
  
  
  CONCLUSIONS
  Intraoperative 3D fluoroscopes can detect clinically significant intra-articular step-off with acceptable measurement errors, using newer devices that enable the use of a conventional C-arm and reduced radiation.
authors.affiliation: Department of Orthopaedics, Hadassah-Hebrew University Hospital, POB 12000, 91120 Jerusalem, Israel. weily@hadassah.org.il
authors.forename: Yoram A
authors.initials: YA
authors.lastname: Weil
authors.forename: Meir
authors.initials: M
authors.lastname: Liebergall
authors.forename: Rami
authors.initials: R
authors.lastname: Mosheiff
authors.forename: Syndie B
authors.initials: SB
authors.lastname: Singer
authors.forename: Leo
authors.initials: L
authors.lastname: Joskowicz
authors.forename: Amal
authors.initials: A
authors.lastname: Khoury
mesh_terms: D002102:Cadaver; D005260:Female; D005471:Fluoroscopy / Q000379:methods*; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D057072:Intra-Articular Fractures / Q000000981:diagnostic imaging* / Q000601:surgery; D007718:Knee Injuries / Q000000981:diagnostic imaging* / Q000601:surgery; D008297:Male; D016343:Monitoring, Intraoperative / Q000379:methods*; D010027:Osteotomy / Q000379:methods; D012680:Sensitivity and Specificity