Trends in surgery for developmental dysplasia of the hip before and after introduction of improved detection pathways: a population-based cohort study, Scotland 1997–2014

Abstract

BackgroundDevelopmental dysplasia of the hip diagnosed in early infancy (<10 weeks of age) is usually successfully treated with abduction harnessing. Later diagnosis carries an increasing risk of need for surgical treatment and poorer outcomes. MethodsFor all children born in Scotland in April 1997 to March 11, we compared the risk of surgery for developmental dysplasia of the hip by age 3 years (follow up to March, 2014). We compared risks for children born before and after implementation of improved detection pathways. Under usual care in Scotland, all babies undergo clinical examination of the hip (Ortolani and Barlow tests) by a non-specialist examiner as part of the examinations done at birth and 6–8 weeks. Babies with positive findings and those with risk factors for developmental dysplasia of the hip are referred for further investigation. Two areas of Scotland (NHS Lothian and Fife) independently introduced improved detection pathways between April 2002 and March 2005, employing a specialist physiotherapist and paediatrician, respectively, to increase awareness of the condition, train staff undertaking newborn hip examinations, and improve access to expert hip examination and ultrasound scans. We used a logistic regression model of first surgery for developmental dysplasia of the hip by age 3 as recorded in national hospital discharge records on an area by period interaction to estimate the difference in difference. FindingsAmong 777 375 live births in Scotland in April 1997 to March 2011, 918 children underwent first surgery for developmental dysplasia of the hip by age 3 years (1·18 per 1000 live births, 95% CI 1·11–1·26). The risk of surgery for babies born in the post-introduction period (April 2005 to March 2011) compared with the pre-introduction period (April 1997 to March 2002) halved in the intervention areas (NHS Lothian and Fife combined) but remained unchanged elsewhere in Scotland (ratio for the difference in change of risk 0·46, 95% CI 0·31–0·70). InterpretationImplementation of enhanced detection pathways can substantially reduce late diagnosis of developmental dysplasia of the hip and associated requirement for surgical correction. Current models of care based on non-specialist clinical hip examination are associated with unacceptably high rates of late diagnosis. FundingDAM is funded by a Wellcome Trust intermediate clinical fellowship (and Beit fellowship) (201492/Z/16/Z). JRM is funded by a Medical Research Council clinician scientist fellowship.