Dynamic Ultrasound Technique

Proposed Standard Currently Under Review by the American College of Radiology - Comments should be directed to Dr. Harcke at (302) 651-4640, phone; (302) 651-4626, fax, Email address: tharcke@aidi.nemours.org



These standards and guidelines have been developed to assist practitioners performing ultrasound studies of the infant hip. Adherence to the following standards will maximize the probability of detecting most of the abnormalities that relate to hip position, hip stability, and development of the acetabulum.


Ultrasonography serves as an excellent method for diagnostic imaging of the immature hip. Sonography affords direct visualization of the cartilaginous components of the hip joint. The value of ultrasonography diminishes as development of the ossification center occurs. Between six months and a year of age, radiography becomes more reliable. Usually by one year of age the center is sufficiently developed to prevent good visualization of the acetabulum with ultrasound.

Sonography of the infant hip can be used both in the diagnosis of developmental dysplasia of the hip (DDH)* and in monitoring treatment (when performed using customary splint type devices). Risk factors for DDH include abnormal findings on clinical examination, family history of DDH, breech presentation at birth, and postural molding conditions (torticollis, foot deformity). Although females have a higher prevalence of DDH than males, gender alone is not considered a risk factor.

*This term has replaced the term congenital dysplasia (dislocation) of the hip (CDH). (1)


See the ACR Standard for Performing and Interpreting Diagnostic Ultrasound Examinations (1992, Res 9).


The diagnostic examination of the infant hip incorporates two orthogonal views which are adequate in themselves to provide an assessment of hip position, stability, and morphology when the study is correctly performed and interpreted. It should be noted that additional views and maneuvers can be obtained and that these may enhance the confidence of the examiner.

Examination of the hip to diagnose DDH should include examination at rest and when stress is applied. Morphology is assessed at rest. The stress maneuvers follow those prescribed in the clinical examination of the hip and check hip stability.(1) These attempts to dislocate the femoral head or reduce a displaced head are analogous to the Barlow and Ortolani tests used in the clinical examination.(2) It is important that the infant is relaxed when hips are assessed for instability. It is acceptable to perform the standard exam with the infant in a supine or lateral position.

Components of the hip exam:

The diagnostic exam should include a coronal view in the standard plane at rest and a transverse view of the flexed hip with and without stress.

  1. I. Femoral Position

    1. Neutral: The femoral shaft is in the position of rest, usually 15-20 degrees of hip flexion.
    2. Flexed: The femoral shaft is flexed 90 degrees at the hip.

  2. II. Imaging Planes and Views

    1. Coronal Plane: This is an anatomic term defining the usual anatomic plane through the body which is approximately parallel to the posterior skin surface of an infant.
    2. Coronal View in the Standard Plane: This is an ultrasound view of the infant hip obtained with the transducer in a slightly oblique CORONAL plane. An image obtained with the transducer in the anatomic coronal plane will result in a curved appearance of the iliac bone superior to the acetabulum. For standardization and reproducibility, a straight or nearly straight appearance of the ilium is desirable. If the superior edge of the transducer is rotated 10-15 degrees (usually posteriorly) into an oblique coronal plane, the ilium will appear straight, and after adjustment to assure that the imaging plane is through the deepest part of the acetabulum, the resulting image will be a coronal image in the standard plane. Since the femoral head is almost spherical, the position of the femur is unimportant in this view, but the view is most easily obtained with the femur in neutral.
    3. Transverse Plane: This is the anatomic Transverse or axial plane (similar to the plane of a primary CT image)
    4. Transverse View: This is the ultrasound view obtained when the femur is in flexion and the transducer is in the transverse plane. The transducer is posterolateral so that imaging can be accomplished while the hip is abducted and adducted. The hip should be evaluated with the femur in flexion at rest and during application of posteriorly directed force (stress, see #3) to assess stability.

  3. III. Stress

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