title: Three-dimensional Assessment of Femoral Head Coverage in Normal and Dysplastic Hips: A Novel Method.
abstract: The acetabular coverage of the femoral head has been assessed in two-dimensions as the projected covered area or the covered angle on plain radiographs. We present a novel method of the three-dimensional assessment of femoral head coverage obtained by evaluating the covered volume of the femoral head in both normal and dysplastic hips. We also assessed the covered angles on the vertical slices passing through the center of the femoral head. The mean covered volume of the femoral head was 57.4% in normal hips and 26.6% in dysplastic hips. In dysplastic hips, the L-CE, A-CE, and P-CE angles were 7.7°, 21.8°, and 95.8°, respectively, while the acetabular angle was 27.5°. In normal hips, the CE angles were 34.0°, 56.8°, and 109.4°, respectively, while the acetabular angle was 7.2°. Our study suggests the usefulness of a novel 3D assessment for acetabular coverage of the femoral head. This assessment provided the precise 3D information necessary to diagnose hip dysplasia and assess the deficiency of acetabular coverage in these patients. Moreover, we may detect a cut-off between normal and dysplastic hips in the 3D assessment by assessing a large number of dysplastic hips both morphologically and using the new assessment.
authors.affiliation: Division of Orthopaedic Surgery, Department of Regenerative and Transplant Medicine, Niigata University Graduate School of Medical and Dental Sciences, Niigata 951-8510, Japan.miyasakad@yahoo.co.jp.
authors.forename: Dai
authors.initials: D
authors.lastname: Miyasaka
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Ito
authors.forename: Norio
authors.initials: N
authors.lastname: Imai
authors.forename: Ken
authors.initials: K
authors.lastname: Suda
authors.forename: Izumi
authors.initials: I
authors.lastname: Minato
authors.forename: Yoichiro
authors.initials: Y
authors.lastname: Dohmae
authors.forename: Naoto
authors.initials: N
authors.lastname: Endo
mesh_terms: D000077:Acetabulum / Q000000981:diagnostic imaging; D000293:Adolescent; D000328:Adult; D005260:Female; D005270:Femur Head / Q000000981:diagnostic imaging*; D006617:Hip Dislocation / Q000000981:diagnostic imaging*; D006621:Hip Joint / Q000000981:diagnostic imaging*; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008297:Male; D015588:Observer Variation; D015203:Reproducibility of Results; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed; D055815:Young Adult