Hip dysplasia and ultrasound imaging of whole populations: the precautionary principle revisited

Current screening recommendations for developmental dysplasia of the hip may lead to an increase in open reduction

Most centres in the United Kingdom adopt a selective screening programme for developmental dysplasia of the hip (DDH) based on repeated clinical examination and selective ultrasound examination. The Newborn Infant Physical Examination protocol implemented in 2008 recommends a first examination at birth and then a second and final examination at six to ten weeks of age. Due to concerns over an increase in late presentations we performed a retrospective review of our 15-year results to establish if late presentation increases treatment requirements. Of children presenting before six weeks of age, 84% were treated successfully with abduction bracing, whereas 86% of children presenting after ten months eventually required open reduction surgery. This equates to a 12-fold increase in relative risk of requiring open reduction following late presentation. Increasing age at presentation was associated with an increase in the number of surgical procedures, which are inevitably more extensive and complex, with a consequent increased in cost per patient. The implementation of an opportunistic examination at three to five months could help to reduce the unintended consequences of the Newborn Infant Physical Examination programme.

Developmental dysplasia of the hip

In its severest form, developmental dysplasia of the hip is one of the most common congenital malformations. The pathophysiology and natural history of the range of morphological and clinical disorders that constitute developmental dysplasia of the hip are poorly understood. Neonatal screening programmes, based on clinical screening examinations, have been established for more than 40 years but their effectiveness remains controversial. Whereas systematic sonographic imaging of newborn and young infants has afforded insights into normal and abnormal hip development in early life, we do not clearly understand the longer-term outcomes of developmental hip dysplasia, its contribution to premature degenerative hip disorders in adult life, and the benefits and harms of newborn screening. High quality studies of the adult outcomes of developmental hip dysplasia and the childhood origins of early degenerative hip disease are needed, as are randomised trials to assess the effectiveness and safety of neonatal screening and early treatment.