Computed tomographic measurement of acetabular and femoral component version in total hip arthroplasty

Purpose The purposes of the present study were (1) to investigate the variation and accuracy of both acetabular and femoral component version on the axial computed tomographic (CT) images, and (2) to better define the associations between the components version and clinical factors. Methods We investigated acetabular and femoral component orientation in 1,411 primary total hip arthroplasties that had been performed without computer-assisted navigation. Version of the acetabular and femoral components was measured on the axial CT images. Results The component version was significantly greater than the native version in both acetabular and femoral version. There was a significant correlation between the stem and native femoral versions, but not between the acetabular component and native acetabular versions. Conclusion This study identifies several features that might help analyse the effect of pre-operative native acetabular and femoral version on the variation of component alignment.