Role of ultrasound in congenital hip dysplasia.

AnnotationsRole of ultrasound in congenital hip dysplasia Ultrasound examination of the hip was first introduced by Graf as a way of assessing surface contour of the pelvis.'It was soon apparent that ultrasound could image the soft tissue components of the infant hip, that is the femoral head and cartilaginous acetabulum, and information could be gained about developmental anatomy and hip location.Concerns about the specificity and sensitivity of the clinical screening tests for neonatal hip instability prompted an enthusiastic approach by many to the use of ultrasound in the diagnosis and management of congenital dislocation of the hip (CDH).Clarke et al proposed a multiplanar ultrasound examination of the hip with the emphasis on dynamic assessment.2Real time imaging of the hip with 'provocation' of joint instability, effectively a Barlow's test, allows femoral head displacement to be assessed dynamically.Graf's technique of static measurement relies more on the morphological appearances ofthe cartilaginous acetabulum.Two angles are calculated.The 'alpha' angle defines the slope ofthe superior aspect of the osseous acetabulum while the 'beta' angle evaluates the cartilaginous acetabular component.The hip is thus classified into four main types3