title: Measurement variability of the lateral head-shaft angle in slipped capital femoral epiphysis.
abstract: The lateral head-shaft angle as described by Southwick is used to assess the severity of slipped capital femoral epiphysis and to measure progression. Intraobserver variability in measuring the lateral head-shaft angle may influence decision making. The purpose of this study was to determine intraobserver variability in the measurement of the lateral head-shaft angle of slipped capital femoral epiphysis. The lateral head-shaft angle of 108 hips was measured twice by three observers. The two-way analysis of variance method of Bland and Altman as outlined by Loder was used to determine the intraobserver variability. For the lateral head-shaft angle in slipped capital femoral epiphysis, the intraobserver variability was +/-5.9 degrees . To ensure true change, a single observer should document at least a 12 degrees change in the lateral head-shaft angle between two radiographs.
authors.affiliation: Department of Orthopaedic Surgery, Dartmouth-Hitchcock Medical Center, One Medical Center Drive, Lebanon, NH 03756-0001, USA. bcarney58@hotmail.com
authors.forename: Brian T
authors.initials: BT
authors.lastname: Carney
authors.forename: Joseph
authors.initials: J
authors.lastname: Liljenquist
mesh_terms: D000293:Adolescent; D002648:Child; D004839:Epiphyses, Slipped / Q000473:pathology*; D005260:Female; D005269:Femur / Q000473:pathology*; D006621:Hip Joint / Q000473:pathology*; D006801:Humans; D008297:Male; D015588:Observer Variation