Ultrasonography in developmental dysplasia of the hip: what have we learned?

Developmental dysplasia of the hip (DDH) is an important but poorly defined entity, the natural history of which is incompletely understood. The term encompasses a disease spectrum ranging from a stable hip with a mildly dysplastic acetabulum to complete hip dislocation. Much controversy surrounds the diagnosis, imaging and management of this condition. We present a review of the history of US imaging of DDH from the radiologist's perspective, summarising the most widely recognised US methods described to date. We discuss controversies in the approach to US examination, with particular emphasis on current opinions. The existing scientific evidence for and variations in the practice of US screening for DDH, including recommendations from the United States Preventive Services Task Force and the ESPR DDH Taskforce Group respectively, are discussed.