Three-Dimensional Morphological Characteristics Measurement of the Hip Based on Computed Tomography Image Post-Processing

Background: Traditional morphological values were measured 20 years ago based on cadaver and radiograph. The curative effect was greatly improved by these parameters, but is still not perfect now. One remaining inaccuracy we can ascribe to is the accuracy of these radiograph parameters. The purpose of this study was to measure the traditional morphological values based on the 3-dimensional measurements, which provide some new repeatable parameters of hip. Methods: 400 consecutive participants with both CT and X-ray radiograph records were retrospectively admitted in our research. We measured neck shaft angle, femoral neck offset and CFI (canal flare index) on both radiograph and 3D-CT view. We created two new parameters which can only be measured on CT views. Results: After measurements of the morphological references, we found similarity among 3-D CT values, traditional radiograph values and cadaver values, the gap had no statistical meanings. But it can be always found ICC (intraclass correlation coefficient) is higher in 3-D CT values, especially for the measurement of femoral offset. Conclusions: The study suggested traditional radiograph was correct but not accurate enough. 3-D CT reconstruction is necessary when the value of the femoral offset value was essential.