Evaluation of computed tomography for determining the diagnosis of acetabular fractures.
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.
O'Toole
Robert V
RV
R Adams Cowley Shock Trauma Center, Department of Orthopaedics, University of Maryland School of Medicine, Baltimore, MD 21201, USA. rvo3@yahoo.com
Cox
Garrick
G
Shanmuganathan
K
K
Castillo
Renan C
RC
Turen
Clifford H
CH
Sciadini
Marcus F
MF
Nascone
Jason W
JW
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