title: Three-dimensional patterns of early acetabular cartilage damage in hip dysplasia; a high-resolutional CT arthrography study.
abstract: OBJECTIVE
  The purpose of this study was to examine the three-dimensional (3D) progression patterns of early acetabular cartilage damage in hip dysplasia using high-resolutional computed tomography (CT) arthrography.
  
  
  METHODS
  Thirty-two dysplastic hips of 26 Japanese symptomatic females including 21 hips in pre-stage of osteoarthritis (Kellgren-Lawrence (K-L) grade 0; mean patient age, 32.0 years) and 11 hips in early stage of osteoarthritis (K-L grade 1 or 2; mean patient age, 32.8 years) were examined. Isotropic high-resolutional CT arthrography with an image resolution of 0.5 mm in any orthogonal direction was performed. A 3D acetabular cartilage model was generated and we evaluated distribution of cartilage thickness in 12 zones after dividing the weight-bearing area of the hip joint in radial and lateral/medial directions.
  
  
  RESULTS
  In pre-stage of osteoarthritis, significant differences in cartilage thickness were observed between the lateral and medial zones in all radial regions, most prominently in the antero-superior region. In early stage of osteoarthritis, no significant differences in cartilage thickness were observed, except in the most posterior region. The lateral-medial (LM) ratio was defined as cartilage thickness in the lateral zone divided by that in the medial zone, and hips with the LM ratio in the antero-superior region of <1.4 had significantly more extensive involvement of labral tears than hips with the LM ratio of ≥1.4.
  
  
  CONCLUSIONS
  In hip dysplasia, acetabular cartilage damage was probably occurred in the antero-superior lateral area. The LM ratio may be a sensitive index to quantify early cartilage damage associated with extent of labral disorders.
authors.affiliation: Department of Orthopaedic Medical Engineering, Osaka University Medical School, Osaka, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Tamura
authors.forename: T
authors.initials: T
authors.lastname: Nishii
authors.forename: T
authors.initials: T
authors.lastname: Shiomi
authors.forename: Y
authors.initials: Y
authors.lastname: Yamazaki
authors.forename: K
authors.initials: K
authors.lastname: Murase
authors.forename: H
authors.initials: H
authors.lastname: Yoshikawa
authors.forename: N
authors.initials: N
authors.lastname: Sugano
mesh_terms: D000077:Acetabulum / Q000000981:diagnostic imaging* / Q000473:pathology; D000293:Adolescent; D000328:Adult; D001175:Arthrography / Q000379:methods; D002358:Cartilage, Articular / Q000000981:diagnostic imaging* / Q000473:pathology; D042241:Early Diagnosis; D006618:Hip Dislocation, Congenital / Q000150:complications* / Q000000981:diagnostic imaging / Q000473:pathology; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D021621:Imaging, Three-Dimensional / Q000379:methods; D008875:Middle Aged; D015207:Osteoarthritis, Hip / Q000000981:diagnostic imaging / Q000209:etiology* / Q000473:pathology; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed / Q000379:methods; D055815:Young Adult