THE INFLUENCE OF SELECTIVE ULTRASOUND SCREENING ON INCIDENCE OFLATE PRESENTING DEVELOPMENTAL HIP DYSPLASIA: EXPERIENCE FROM LANARKSHIRE, SCOTLAND, 2001–2005

Abstract

Background: Selective ultrasound screening of neonatal hips with risk factors has been undertaken in Lanarkshire from 2001. Referral reasons included family history, breech, clicky hip and instability. Patients are examined by an orthopaedic surgeon with a special interest and scanned by static Graf technique. Our experience with selective screening and its effect on late DDH is presented.

Methods: All ultrasound screening data was collected prospectively and entered into a database. Late presenters were identified at the tertiary centre by case note and X ray review. Population data was obtained from the Scottish registry.

Results: Between 2001–2005, there were 30,824 live-births. 405 babies (910 hips) were identified as being at risk. 5(1.2%) were identified as Graf III/IV. Three responded to splinting, 1 required closed reduction and 1 open reduction. 11 who had initially normal scans were noted to have abnormal acetabular index (> 30) at 6 months. 2 required open reduction, 1 closed reduction and the rest eventually normalised with follow up. True late presentation was identified (> 3 months) in 11 children. Mean age at diagnosis was 14.7m (4–29 mts). 7(64%) did not have any identifiable risk factors. 4 had risk factors, but had escaped screening. 8 underwent open and 3 closed reduction. 7 derotation osteotomies and 1 pelvic osteotomy were additionally performed.

Discussion: The identifiable incidence of DDH in Lanarkshire is 0.87/1000. The incidence of true late presenting DDH in the same population was 0.35/1000. If all hips with risk factors had been successfully screened it would reduce to 0.22/1000. Selective screenings can minimise the incidence of late presenting DDH if rigorously implemented. Majority of late presenters do not have risk factors and are likely to escape detection with a selective screening programme. This suggests a different natural history in late presenting cases.