title: Reproducibility of radiographic hip measurements in adults.
abstract: BACKGROUND
  Hip dysplasia may cause pain and premature hip osteoarthritis. Here, our objective was to assess the inter- and intraobserver reproducibility of radiographic hip parameter measurement in adults.
  
  
  METHODS
  We used anteroposterior pelvic radiographs and false-profile lateral hip radiographs from 30 individuals (60 hips) enrolled in a prevalence study of hip osteoarthritis. For each hip, two independent observers recorded five parameters twice, at an interval of 1 month. The five parameters were the vertical-center-edge angle (VCE), the anterior center-edge angle (vertical-center-anterior angle, VCA), the acetabular roof angle (HTE), the neck-shaft angle (CC'D), and acetabulum depth (AD). Reproducibility was assessed using Bland-Altman plots, intraclass correlation coefficients (ICCs), and kappa coefficients for the radiographic diagnosis of hip dysplasia using widely accepted cutoffs.
  
  
  RESULTS
  Of the 60 hips, 51 were assessable. Intraobserver ICC values ranged from 0.72 to 0.94 and interobserver ICC values from 0.68 to 0.84. Kappa coefficients were between 0.60 and 1.00, except for the VCA angle (κ=0.41).
  
  
  CONCLUSIONS
  In this study, reproducibility of the main radiographic hip parameters was good according to all evaluation methods used. However, CC'D and, to an even greater extent, the VCA angle seemed challenging to measure.
authors.affiliation: Service de radiologie, CHU la Cavale-Blanche, 29609 Brest, France.
authors.forename: Ronan
authors.initials: R
authors.lastname: Bouttier
authors.forename: Johanne
authors.initials: J
authors.lastname: Morvan
authors.forename: Bernard
authors.initials: B
authors.lastname: Mazieres
authors.forename: Anne-Christine
authors.initials: AC
authors.lastname: Rat
authors.forename: Liana Euller
authors.initials: LE
authors.lastname: Ziegler
authors.forename: Patrice
authors.initials: P
authors.lastname: Fardellone
authors.forename: Bruno
authors.initials: B
authors.lastname: Fautrel
authors.forename: Francis
authors.initials: F
authors.lastname: Guillemin
authors.forename: Jacques
authors.initials: J
authors.lastname: Pouchot
authors.forename: Christian
authors.initials: C
authors.lastname: Roux
authors.forename: Joël
authors.initials: J
authors.lastname: Coste
authors.forename: Alain
authors.initials: A
authors.lastname: Saraux
mesh_terms: D000077:Acetabulum / Q000000981:diagnostic imaging*; D000328:Adult; D000368:Aged; D005270:Femur Head / Q000000981:diagnostic imaging; D006615:Hip / Q000000981:diagnostic imaging*; D006618:Hip Dislocation, Congenital / Q000000981:diagnostic imaging*; D006801:Humans; D008875:Middle Aged; D015588:Observer Variation; D015207:Osteoarthritis, Hip / Q000000981:diagnostic imaging*; D011859:Radiography; D015203:Reproducibility of Results