title: Reliability of radiological measurements in the assessment of the child's hip.
abstract: We investigated the reproducibility of the various radiological methods of assessment of hip dysplasia by making 474 assessments of hips and quantifying the inter-observer and intra-observer variation. There was a wide range of variability between the readings made by different observers and by one observer on two occasions. A measurement of acetabular index has to be given a range of +/- 6 degrees in order to be 95% confident of including the true measurement. We found the most helpful measurements to be the acetabular index, up to the age of eight years; the centre-edge angle, over the age of five years; and Smith's c/b ratio and neck-shaft angle. We feel, however, that the change in value over a series of radiographs in the same child is much more valuable. Single readings of all the radiological measurements investigated in this study were unreliable.
authors.affiliation: Department of Orthopaedics, Royal Children's Hospital, Victoria, Australia.
authors.forename: N S
authors.initials: NS
authors.lastname: Broughton
authors.forename: D I
authors.initials: DI
authors.lastname: Brougham
authors.forename: W G
authors.initials: WG
authors.lastname: Cole
authors.forename: M B
authors.initials: MB
authors.lastname: Menelaus
mesh_terms: D000077:Acetabulum / Q000000981:diagnostic imaging; D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D006618:Hip Dislocation, Congenital / Q000000981:diagnostic imaging / Q000628:therapy; D006621:Hip Joint / Q000000981:diagnostic imaging*; D006801:Humans; D007223:Infant; D011859:Radiography