title: Evaluation of computed tomography for determining the diagnosis of acetabular fractures.
abstract: OBJECTIVE
  We assessed whether, in contrast to reports in the literature, computed tomographic (CT) scans improve the ability to classify acetabular fractures in comparison with plain radiographs.
  
  
  METHODS
  Prospective.
  
  
  METHODS
  Level I trauma center.
  
  
  METHODS
  Seventy-five patients with 75 acetabular fractures treated between June 2005 and May 2006.
  
  
  METHODS
  Four different image sets for each patient were evaluated: image set A, Judet view plain radiographs plus axial view CT scans; image set B, Judet view plain radiographs alone; image set C, three-dimensional CT reconstructions; and image set D, CT-simulated anteroposterior and Judet views of the pelvis. The 300 image sets were viewed in random order by four orthopaedic trauma fellowship-trained surgeons who independently recorded a diagnosis. A gold standard diagnosis was determined by group consensus.
  
  
  METHODS
  Agreement among four imaging methods was evaluated by using kappa statistics for multiple raters and nominal data.
  
  
  RESULTS
  Comparing the gold standard diagnosis with the four image sets, Judet view plain radiographs had a worse kappa value than CT scans (P < 0.05). The adjusted kappa values for all three image sets that included CT scans averaged greater than 0.62, showing substantial agreement, whereas the image set with plain radiographs alone (image set B) had a lower kappa value of only 0.48 (P < 0.05).
  
  
  CONCLUSIONS
  In contrast to previous reports in the literature, the accuracy of plain radiographs alone was less than the accuracy of CT scans in terms of diagnosis. The interobserver reliability was also worse for plain radiographs alone.
authors.affiliation: R Adams Cowley Shock Trauma Center, Department of Orthopaedics, University of Maryland School of Medicine, Baltimore, MD 21201, USA. rvo3@yahoo.com
authors.forename: Robert V
authors.initials: RV
authors.lastname: O'Toole
authors.forename: Garrick
authors.initials: G
authors.lastname: Cox
authors.forename: K
authors.initials: K
authors.lastname: Shanmuganathan
authors.forename: Renan C
authors.initials: RC
authors.lastname: Castillo
authors.forename: Clifford H
authors.initials: CH
authors.lastname: Turen
authors.forename: Marcus F
authors.initials: MF
authors.lastname: Sciadini
authors.forename: Jason W
authors.initials: JW
authors.lastname: Nascone
mesh_terms: D000077:Acetabulum / Q000000981:diagnostic imaging* / Q000293:injuries* / Q000473:pathology; D050723:Fractures, Bone / Q000000981:diagnostic imaging*; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods; D015588:Observer Variation; D011446:Prospective Studies; D011857:Radiographic Image Interpretation, Computer-Assisted; D015203:Reproducibility of Results; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed / Q000379:methods*; D014193:Trauma Centers