[Congenital dislocation of the hip: a sonographic study].

To investigate congenital dislocation of the hip, we reviewed the clinical records, radiographs, sonograms and arthrograms in 106 neonates and infants. In a series of 212 hips, 122 were normal, 42 were dysplastic, 16 were subluxed, and 32 were dislocated. We compared the efficacy of sonography with that of arthrography in diagnosing CDH (congenital dislocation of the hip). The mean age in our series ws 3.3 months (range: 2 weeks to 12 months). The radiographic, arthrographic, and sonographic findings were classified according to the methods of Ishida, Yamada and of Graf respectively. We compared the radiographs to the sonograms, and found that the diagnostic accuracy of the sonograms was 84.9%, sensitivity was 75.6%, and specificity was 91.8%. The discrepancy between the radiographs to the sonography was related to the pelvic rotation. Morphologically, there was a close correlation between the hip sonography and arthrography. We found that sonography in CDH could predict the reduction achievable by a Pavlik-harness as well as could arthrography. We concluded that sonography was as useful as arthrography for CDH.