Comparison of 4 computed tomographic imaging protocols for lateral tibial plateau fractures

Many computed tomographic (CT) imaging protocols are used for pretreatment assessment of tibial plateau fractures. This study compares the diagnostic capabilities of 4 CT protocols.

Lateral tibial plateau fractures were induced in 19 knee specimens and CT scans were obtained with the following protocols: 1) 3-mm collimation, axial acquisition, 2) 3-mm collimation, helical acquisition, 3) mixed-increment collimation, axial acquisition, and 4) 3-mm collimation, helical acquisition with 50% overlap reconstruction of raw data. Two-dimensional coronal and sagittal reformations and 3-dimensional surface reconstruction images were analyzed for maximum fragment depression, peripheral fragment displacement, fracture pattern classification and quality of image. Specimen dissection established maximal articular surface depression, fragment displacement and actual fracture pattern.

None of the 2-dimensional reformations from the 4 protocols proved statistically superior for determining maximal fracture depression, fragment displacement, or fracture classification. There was a trend toward more accurate fracture classification with the mixed-increment axial protocol and the overlap protocol than either of the 3-mm protocols, but this was not statistically significant. All protocols were statistically equivalent in predicting fracture pattern classification using 3-dimensional images. However, the 3-dimensional images were of significantly higher quality when obtained with either the mixed-increment axial protocol or the overlap protocol.

There were no statistically significant differences in the objective assessment of tibial plateau fractures among the 4 different protocols. The 3-dimensional images derived from the mixed-increment axial protocol and the 3-mm helical protocol with 50% overlap reconstruction were of superior quality.