ABSTRACT
The incidence of developmental dysplasia of the hip (DDH) is 1 per 1000 live births and is four times commoner in females. The left hip is more frequently involved than the right (10:1). Bilateral DDH is commoner than involvement of the right side alone. Risk factors include a breech delivery, being first-born, a positive family history and caesarean section. There is an association with other musculoskeletal abnormalities (e.g. congenital torticollis and congenital foot deformities). Possible aetiological factors include mechanical influences, hormone-induced joint laxity, primary acetabular dysplasia and polygenetic inheritance.
