Correlations between ultrasonographic and subsequent radiographic findings of developmental dysplasia of the hips.

PURPOSE

The study aimed to investigate the utility of ultrasonographic findings in predicting the subsequent radiographic parameters of developmental dysplasia of the hips.

METHODS

In this 12-year retrospective cohort study, all new-born infants with a positive clinical examination or risk factors were included. They were scheduled for hip ultrasonography in the first 3 months, and subsequent radiographs at 1 year of life. The ultrasonographic images were evaluated using the Graf classification, Harcke's dynamic screening method, and Terjesen's femoral head coverage method. The radiographic images were evaluated using the acetabular index and femoral head position. The overall ultrasonographic or radiographic findings were considered abnormal if they were classified as abnormal for any of their respective parameters. The overall ultrasonographic and radiographic parameters were correlated.

RESULTS

A total of 160 patients were included. The overall ultrasonographic and radiographic parameters showed no statistically significant difference (P=0.050). The sensitivity, specificity, and accuracy of the overall ultrasonographic parameters were 57.1%, 84.9%, and 81.3%, respectively. All three individual ultrasonographic parameters showed close correlations, with no statistically significant differences, with the overall radiographic findings and acetabular index (P>0.050). However, they showed a poor correlation, with a statistically significant difference, with the position of the femoral head (P<0.001), with the ultrasonographic parameters having an excellent negative predictive value of 100.0% for identifying an abnormal femoral head position.

CONCLUSION

The current study suggests that ultrasonographic findings evaluated in the first 3 months of life have a close correlation with radiographic findings evaluated at 1 year of life. The ultrasonographic parameters showed an excellent negative predictive value for abnormal femoral head position on radiographs.