A radiologist's guide to the imaging in the diagnosis and treatment of developmental dysplasia of the hip. II. Ultrasonography: anatomy, technique, acetabular angle measurements, acetabular coverage of femoral head, acetabular cartilage thickness, three-dimensional technique, screening of newborns, study of older children.

Developmental dysplasia of the hip (DDH) has a broad spectrum of presentation with the minor findings resolving spontaneously and the most severe ones resulting in disability, if not diagnosed early in life. Diagnosis in the first few months of life allows conservative treatment with complete resolution in most cases. Suspicion of DDH is based on ethnic, family, and pregnancy history, and on physical examination of the newborn. Imaging assists in the diagnosis and follows the treatment. Different modalities have their own advantages and disadvantages. This article deals with ultrasonography.