title: Verification of the Robin and Graham classification system of hip disease in cerebral palsy using three-dimensional computed tomography.
abstract: OBJECTIVE
  We evaluated the validity of the Robin and Graham classification system of hip disease in cerebral palsy (CP) using three-dimensional computed tomography in young people with CP.
  
  
  METHODS
  A total of 91 hips in 91 consecutive children with bilateral spastic CP (57 males, 34 females; nine classified at Gross Motor Function Classification System level II, 42 at level III, 32 at level IV, and eight at level V; mean age 5 y 2 mo, SD 11 mo; range 2-6 y) were investigated retrospectively using anteroposterior plain radiographs and three-dimensional computed tomography (3D-CT) of the hip. The migration percentage was calculated on plain radiographs and all participants were classified into four groups according to migration percentage: grade II, migration percentage ≥ 10% but ≤ 15%, (four hips), grade III, migration percentage >15% but ≤ 30%, (20 hips); grade IV, migration percentage >30% but <100%, (63 hips); and grade V, migration percentage ≥ 100%, (four hips). The lateral opening angle and the sagittal inclination angle of the acetabulum, the neck-shaft angle, and the femoral anteversion of the femur were measured on 3D-CT.
  
  
  RESULTS
  The three-dimensional quantitative evaluation indicated that there were significant differences in the lateral opening angle and the neck-shaft angle between the four groups (Kruskal-Wallis test, p ≤ 0.001).
  
  
  CONCLUSIONS
  This three-dimensional evaluation supports the validation of the Robin and Graham classification system for hip disease in 2- to 7-year-olds with CP.
authors.affiliation: Department of Orthopaedic Surgery, Morinomiya Hospital, Osaka, Japan.
authors.forename: Shinichi
authors.initials: S
authors.lastname: Gose
authors.forename: Takashi
authors.initials: T
authors.lastname: Sakai
authors.forename: Toru
authors.initials: T
authors.lastname: Shibata
authors.forename: Keisuke
authors.initials: K
authors.lastname: Akiyama
authors.forename: Hideki
authors.initials: H
authors.lastname: Yoshikawa
authors.forename: Kazuomi
authors.initials: K
authors.lastname: Sugamoto
mesh_terms: D000077:Acetabulum / Q000000981:diagnostic imaging / Q000473:pathology; D002547:Cerebral Palsy / Q000150:complications*; D002648:Child; D002675:Child, Preschool; D005260:Female; D005269:Femur / Q000000981:diagnostic imaging / Q000473:pathology; D006617:Hip Dislocation / Q000145:classification* / Q000000981:diagnostic imaging* / Q000209:etiology; D006801:Humans; D021621:Imaging, Three-Dimensional; D008297:Male; D015203:Reproducibility of Results; D012720:Severity of Illness Index; D014057:Tomography, X-Ray Computed / Q000379:methods