Plain radiographs fail to reflect femoral offset in total hip arthroplasty

J Arthroplasty. 2014 Aug;29(8):1661-5. doi: 10.1016/j.arth.2014.03.023. Epub 2014 Mar 28.


Successful biomechanical reconstruction is a major goal in total hip arthroplasty (THA). We measured leg length (LL), global (GO) and femoral offset (FO) change on anteroposterior pelvis radiographs and on three-dimensional computed-tomography (3D-CT) with fiducial landmarks after cementless THA on 18 hips of cadaveric specimens. Measurements on radiographs were performed twice by four examiners and showed high interobserver (mean CCC ≥0.79) and intraobserver agreements (mean ICC ≥0.88). Mean differences between radiographic and 3D-CT measurements were 1.0 (SD 2.0) mm for LL, 0.6 (SD 3.6) mm for GO and 1.4 (SD 5.2) mm for FO. 1% of radiographic LL-, 15% of GO- and 35% of FO measurements were outside a tolerance limit of 5mm. Radiographs seem acceptable for measuring LL/GO change but fail to reflect FO change in THA.

Keywords: accuracy; femoral offset; global offset; leg length; radiography; total hip arthroplasty.

Publication types

  • Comparative Study
  • Validation Study

MeSH terms

  • Arthrography / methods
  • Arthrography / standards*
  • Arthrography / statistics & numerical data
  • Arthroplasty, Replacement, Hip / methods*
  • Cadaver
  • Femur / diagnostic imaging*
  • Femur / surgery*
  • Fiducial Markers
  • Humans
  • Imaging, Three-Dimensional / methods
  • Imaging, Three-Dimensional / standards
  • Imaging, Three-Dimensional / statistics & numerical data
  • Observer Variation
  • Pelvis / diagnostic imaging
  • Reproducibility of Results
  • Tomography, X-Ray Computed / methods
  • Tomography, X-Ray Computed / standards*
  • Tomography, X-Ray Computed / statistics & numerical data