title: [Definition of a reproducible method for acetabular anteversion measurement at CT].
abstract: OBJECTIVE
  To demonstrate the variability of acetabular anteversion angle measurement at CT and suggest a new and reproducible method of measurement.
  
  
  METHODS
  Sawbone pelvis based study: We first realized a series of helical CT of the pelvis, with gradual increase in tilt angle, and measured acetabular anteversion angles on axial sections, then on sections parallel to the superior S1 endplate. Then, we made a series of radial sections centered at the acetabulum, and the anteversion angle was measured on each section. Finally, a test series of five in vivo pelvis was performed to evaluate the feasability of our method.
  
  
  RESULTS
  The acetabular anteversion angle varies with pelvis tilt, whereas measurements obtained from sections parallel to the S1 endplate are constant.
  
  
  CONCLUSIONS
  Acetabular anteversion angle should be measured from sections parallel to the S1 endplate, in order to minimize errors during total hip arthroplasties.
authors.affiliation: Service de neuroradiologie et radiologie ostéoarticulaire, Hôpital J. Minjoz, CHU de Besançon. seb.aubry@libertysurf.fr
authors.forename: S
authors.initials: S
authors.lastname: Aubry
authors.forename: A
authors.initials: A
authors.lastname: Marinescu
authors.forename: O
authors.initials: O
authors.lastname: Forterre
authors.forename: M
authors.initials: M
authors.lastname: Runge
authors.forename: P
authors.initials: P
authors.lastname: Garbuio
mesh_terms: D000077:Acetabulum / Q000033:anatomy & histology* / Q000000981:diagnostic imaging*; D005240:Feasibility Studies; D006801:Humans; D015203:Reproducibility of Results; D014057:Tomography, X-Ray Computed