title: Hyaline cartilage thickness in radiographically normal cadaveric hips: comparison of spiral CT arthrographic and macroscopic measurements.
abstract: OBJECTIVE
  To assess spiral multidetector computed tomographic (CT) arthrography for the depiction of cartilage thickness in hips without cartilage loss, with evaluation of anatomic slices as the reference standard.
  
  
  METHODS
  Permission to perform imaging studies in cadaveric specimens of individuals who had willed their bodies to science was obtained from the institutional review board. Two independent observers measured the femoral and acetabular hyaline cartilage thickness of 12 radiographically normal cadaveric hips (from six women and five men; age range at death, 52-98 years; mean, 76.5 years) on spiral multidetector CT arthrographic reformations and on coronal anatomic slices. Regions of cartilage loss at gross or histologic examination were excluded. CT arthrographic and anatomic measurements in the coronal plane were compared by using Bland-Altman representation and a paired t test. Differences between mean cartilage thicknesses at the points of measurement were tested by means of analysis of variance. Interobserver and intraobserver reproducibilities were determined.
  
  
  RESULTS
  At CT arthrography, mean cartilage thickness ranged from 0.32 to 2.53 mm on the femoral head and from 0.95 to 3.13 mm on the acetabulum. Observers underestimated cartilage thickness in the coronal plane by 0.30 mm +/- 0.52 (mean +/- standard error) at CT arthrography (P < .001) compared with the anatomic reference standard. Ninety-five percent of the differences between CT arthrography and anatomic values ranged from -1.34 to 0.74 mm. The difference between mean cartilage thicknesses at the different measurement points was significant for coronal spiral multidetector CT arthrography and anatomic measurement of the femoral head and acetabulum and for sagittal and transverse CT arthrography of the femoral head (P < .001). Changes in cartilage thickness from the periphery to the center of the joint ("gradients") were found by means of spiral multidetector CT arthrography and anatomic measurement.
  
  
  CONCLUSIONS
  Spiral multidetector CT arthrography depicts cartilage thickness gradients in radiographically normal cadaveric hips.
authors.affiliation: Department of Skeletal Radiology and Pathology, Lariboisière Teaching Hospital, 2 rue Ambroise Paré, 75475 Paris Cedex 10, France. annabelle.wyler@lrb.aphp.fr
authors.forename: Annabelle
authors.initials: A
authors.lastname: Wyler
authors.forename: Valérie
authors.initials: V
authors.lastname: Bousson
authors.forename: Catherine
authors.initials: C
authors.lastname: Bergot
authors.forename: Marc
authors.initials: M
authors.lastname: Polivka
authors.forename: Eric
authors.initials: E
authors.lastname: Leveque
authors.forename: Eric
authors.initials: E
authors.lastname: Vicaut
authors.forename: Jean-Denis
authors.initials: JD
authors.lastname: Laredo
mesh_terms: D000077:Acetabulum / Q000033:anatomy & histology; D000368:Aged; D000369:Aged, 80 and over; D001175:Arthrography / Q000379:methods; D002102:Cadaver; D002358:Cartilage, Articular / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D004210:Dissection; D005260:Female; D005270:Femur Head / Q000033:anatomy & histology; D006621:Hip Joint / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D006801:Humans; D051457:Hyaline Cartilage / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D012015:Reference Standards; D015203:Reproducibility of Results; D036542:Tomography, Spiral Computed / Q000379:methods