The effect of ultrasound screening on late developmental dysplasia of the hip.

Hernandez and Hensinger 1 infer that our study 2,3 shows no effect of ultrasound screening on the prevalence of late subluxated or dislocated developmental dysplasia of the hip (DDH). Our study did not exclude the possibility of no effect ( P =.11), but our data are also compatible with a significant effect of ultrasound screening. The risk for late DDH among infants undergoing ultrasound screening was 4.6 times less than the risk among infants undergoing only clinical screening (relative risk, 4.6; 95% confidence interval, 0.5-217). 2,3 Our study represents to the best of our knowledge the best attempt so far to estimate the effect of ultrasound screening on late See also pages 641 and 643 prevalence, based on a random allocation of newborns into ultrasound and reference groups. Other studies have reported a reduced prevalence of late DDH after introduction of ultrasound screening, using historical reference groups. 4,5 Estimates of the