Twenty years experience of selective secondary ultrasound screening for congenital dislocation of the hip

The authors report the results of a selective ultrasound screening programme for congenital dislocation of the hip (CDH) over a period of 20 years, with the aim of defining the rate of screening, conservative treatment and late presentation requiring surgery.

All neonates born from June 1988 to December 2008 (inclusive) were included in the prospective cohort, with a minimum follow-up of 12 months. All underwent an early clinical examination of the hips and those with clinical instability were referred for ultrasound at 2 weeks; those with risk factors were sonographically examined at 6 weeks. Risk factors were defined as breech presentation, family history or foot deformity.

107 440 live births were clinically examined, 20 344 (18.9%) were referred for ultrasound assessment at either 2 weeks (due to clinical signs) or 6 weeks (due to risk factors). 774 (3.8%) were diagnosed with dysplasia with a crude overall treatment rate of 7.2 per 1000 live births. 37 (0.34 per 1000) presented late, that is, after 12 weeks of age; none had detectable clinical signs or risk factors. There were no false negatives.

Elective screening for developmental dysplasia of the hip in association with one stop treatment and monitoring is an effective programme. The number of infants referred increased statistically significantly year on year over the study period and generated more activity. Pavlik harness treatment rates remained acceptable and steady over the period, despite the increase in referrals. The incidence of late presenting cases ranged from 0 to 4 per year, with no secular trend and there were no ultrasound false negatives.