title: Ultrasonographic hip morphometry in infants.
abstract: Ultrasonographic study of 463 normal children (926 hips) from birth to 6 months of age with equal sex distribution was performed. Hip morphometry, including Graf's alpha and beta angles. Morin's head coverage percentage, and head size were measured. Using the same technique, a group of 52 babies was measured longitudinally from birth to 6 months of age, with three measurements taken for each hip for a total of 312 measurements. Results showed that the boys had a consistently higher alpha angle, a lower beta angle, better head coverage, and larger head size through the 6 months. Differences between the right and left hips were only noted in the beta angle. The containment of the hip was found to increase rapidly in the first 4 months. Comparing data from the longitudinal versus the cross-sectional group, no statistically significant differences were detectable in all the parameters measured. Intraobserver variations were found to be best with alpha angle measurements, with a standard deviation of 3.22 degrees.
authors.affiliation: Department of Orthopaedics and Traumatology, Faculty of Medicine, Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, N.T.
authors.forename: J C
authors.initials: JC
authors.lastname: Cheng
authors.forename: Y L
authors.initials: YL
authors.lastname: Chan
authors.forename: P W
authors.initials: PW
authors.lastname: Huí
authors.forename: W Y
authors.initials: WY
authors.lastname: Shen
authors.forename: C
authors.initials: C
authors.lastname: Metreweli
mesh_terms: D017677:Age Distribution; D044466:Asian People; D002681:China; D003430:Cross-Sectional Studies; D005260:Female; D006621:Hip Joint / Q000033:anatomy & histology* / Q000000981:diagnostic imaging*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008137:Longitudinal Studies; D008297:Male; D015588:Observer Variation; D012016:Reference Values; D014463:Ultrasonography