Femoral anteversion measurement : evaluation of inter- and intraobserver reliability


anteversion angle ; interobserver ; intra- observer ; reliability ; CT scan

Published online: May 29 2020

Olivia Behaeghe, Annelies Van Beeck, Lieven Dossche, Johan Somville

From the UZA, Antwerp, Belgium


The aim of this study was to evaluate the inter- and intraobserver reliability of a CT-based femoral anteversion measurement.

17 CT scans showing an abnormal anteversion on one side were presented to 6. Three measurements of all scans were obtained : two bilateral measurements and a third measurement with a flipped CT scan.

Interobserver correlation results using the spearman test for left, right and anteversion difference had a mean of respectively : 0.918, 0.760 and 0.757.

Intraobserver correlation had a maximum of respectively : 0,99, 0,89 and 0,94. Correlation coefficients were consistently higher for the second measurement. The lower correlation boarder of 0,8 was often exceeded. Intraobserver correlation was higher than interobserver correlation.

As we evaluated a high variance in interobserver reliability, we recommend an accurate and objective measurement of the anteversion angle. A personal measurement and comparison to the radiological protocol is necessary.