title: The 'true' acetabular index in children with cerebral palsy.
abstract: BACKGROUND
  The acetabular index is a measurement used to determine whether or not an acetabular osteotomy may be required at the time of hip reconstruction in children.
  
  
  METHODS
  A retrospective analysis of pre- and postoperative values of the acetabular index was carried out on two groups of children. One group of children had an acetabuloplasty and the other did not during hip reconstruction, the decision being made at the time of open reduction, based on lack of hip congruity.
  
  
  RESULTS
  When the pre-operative acetabular index measurements were reviewed, the mean difference between the two groups was only 7 degrees. Range of measurements was similar between the two groups.
  
  
  CONCLUSIONS
  The acetabular index is difficult to measure in some children with cerebral palsy. The bony landmarks are difficult to standardise. This may explain the similar pre-operative values between the two groups of children in this study. We, therefore, recommend that before hip reconstruction in children with cerebral palsy, the measurement of the acetabular index should be abandoned. Decisions as to whether to undertake an acetabuloplasty or not should be made at the time of open reduction.
authors.affiliation: Orthopaedic Department, Guy's Hospital, Guy's & St Thomas' NHS Trust, London, UK.
authors.forename: J D
authors.initials: JD
authors.lastname: Spencer
authors.forename: M S
authors.initials: MS
authors.lastname: Sait
mesh_terms: D000077:Acetabulum / Q000473:pathology* / Q000601:surgery; D000293:Adolescent; D002547:Cerebral Palsy / Q000473:pathology*; D002648:Child; D002675:Child, Preschool; D006801:Humans; D010027:Osteotomy / Q000379:methods*; D011300:Preoperative Care / Q000379:methods; D012189:Retrospective Studies