THE EFFECT OF SELECTIVE ULTRASOUND SCREENING ON THE INCIDENCE OF LATE DDH IN GREATER GLASGOW REGION

Abstract

Introduction: To measure the incidence of late presenting DDH following the introduction of selective ultrasound screening of neonatal hips with associated risk factors.

Method: Retrospective cohort study of children with late diagnosed DDH in a defined population of Greater Glasgow Region. A hip ultrasound program was introduced in the year 1997 for secondary screening of children with risk factors for DDH. The departmental and theatre database was used to identify children with late diagnosed DDH. (Defined as diagnosed 3 months after birth) Demographic details, age at presentation, presence of risk factors (Breech presentation, family history, clicks, caesarian section) and details of treatment were recorded. The number of live births for each year was obtained from the General Registrar Office for Scotland. The incidence of late presenting DDH was calculated taking in to account the year of child’s birth. The incidence of late DDH was then compared between the period 1992 –1996 and 1997– 2001.

Results: 78 children were identified, of which 49 babies were between 1992 – 96 and 29 between 1997 –01. The average age at diagnosis was 17 months (Median 15 months, range 5 –84 months). The average annual incidence from 1992 –6 was 0.84 per 1000 live births and from 1997 – 2001 was 0.57 per 1000 live births. This decrease in incidence of late DDH was not significant at 5% level (chi squared p = 0.088). 64 children (82%) with late diagnosed DDH had no factors that could be perceived as risk factors for the condition.

Discussion: Targeted ultrasound screening of babies with risk factors appears to have reduced the average incidence of late DDH from 0.84 to 0.57 per 1000 live births. However this reduction in incidence is not statistically significant. The vast majority of late presenters (82%) do not have risk factors. It remains unclear whether universal ultrasound screening program, practiced in some parts of United Kingdom is a cost effective alternative to eliminate the incidence of late presenting DDH.