Significant differences in femoral torsion values depending on the CT measurement technique

Introduction This study compared the feasibility of six different CT-based measurement techniques for establishing an indication for derotational osteotomy in the cases of patellar instability or femoral fracture.Materials and methods CT scans of 52 single human cadaver femora were measured using six different torsion measurement techniques (described by Waidelich, Murphy, and Yoshioka on transverse images and Hernandez, Jarrett, and Yoshioka on oblique images). All measurements were performed by four observers twice to assess intraobserver and interobserver agreement. The intraclass correlation coefficient (ICC), ANOVA, and Bonferroni post hoc test were used for the statistical analysis.Results Significant differences (P Conclusions Femoral torsion values depend on the measurement technique. When derotational osteotomy is being considered, it is essential to use different threshold values depending on the measurement technique.