title: Ultrasound quantification of acetabular rounding in hip dysplasia: reliability and correlation to treatment decisions in a retrospective study.
abstract: Currently, acetabular rounding is only subjectively assessed on ultrasound for developmental dysplasia of the hip. We tested whether acetabular rounding can be quantified reliably and can distinguish between hips requiring and not requiring treatment. Consecutive infants (n = 90) suspected of having dysplasia of the hip, seen at a pediatric orthopedic clinic, were separated into four diagnostic categories (normal, borderline but resolved, treated by brace, treated surgically). Acetabular rounding was assessed by semi-quantitative grade (0 = nil, 1 = mild, 2 = moderate, 3 = severe) by three observers and by direct measurement of acetabular radius of curvature (AROC) by two observers. Inter-observer reliability of rounding grade was poor (κ = 0.30-0.37). AROC had an inter-observer intra-class correlation coefficient of 0.84 and coefficient of variation of 29%-34%. Mean AROC was significantly higher for hips requiring treatment than for those not requiring treatment (3.3 mm vs. 1.6 mm, p = 0.007). AROC reliably quantifies an observation currently being made subjectively by radiologists and surgeons, and may be useful as a supplementary ultrasound index of dysplasia of the hip in future prospective studies.
authors.affiliation: Department of Radiology and Diagnostic Imaging, 2A2.41WC Mackenzie Health Sciences Centre, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Edwin
authors.initials: E
authors.lastname: Cheng
authors.affiliation: Department of Biomedical Engineering, 1082 Research Translation Facility, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Myles
authors.initials: M
authors.lastname: Mabee
authors.affiliation: Department of Radiology and Diagnostic Imaging, 2A2.41WC Mackenzie Health Sciences Centre, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Vimarsha G
authors.initials: VG
authors.lastname: Swami
authors.affiliation: Department of Radiology and Diagnostic Imaging, 2A2.41WC Mackenzie Health Sciences Centre, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Yeli
authors.initials: Y
authors.lastname: Pi
authors.affiliation: Department of Biomedical Engineering, 1082 Research Translation Facility, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Richard
authors.initials: R
authors.lastname: Thompson
authors.affiliation: Division of Orthopedic Surgery, Department of Surgery, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Sukhdeep
authors.initials: S
authors.lastname: Dulai
authors.affiliation: Department of Radiology and Diagnostic Imaging, 2A2.41WC Mackenzie Health Sciences Centre, University of Alberta, Edmonton, Alberta, Canada. Electronic address: jjaremko@ualberta.ca.
authors.forename: Jacob L
authors.initials: JL
authors.lastname: Jaremko
mesh_terms: D000077:Acetabulum / Q000002:abnormalities* / Q000000981:diagnostic imaging*; D059925:Anatomic Landmarks / Q000000981:diagnostic imaging*; D002648:Child; D005260:Female; D006617:Hip Dislocation / Q000000981:diagnostic imaging* / Q000628:therapy*; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D007223:Infant; D008297:Male; D011379:Prognosis; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D016896:Treatment Outcome; D014463:Ultrasonography / Q000379:methods*
keywords: Acetabular rounding; Developmental dysplasia of the hip; Reliability; Ultrasound; α angle