Top Tips Ultrasound of Developmental Dysplasia of the Hips in Infants

In recent years, the use of Sonography for the diagnosis of Developmental Dysplasia of the Hip (DDH) in Infants has gained importance.

Today, Graf’s techniques is used world-wide to correctly diagnose Infant Hip Dysplasia. Ultrasound allows the medical interpretation to be reproducible, reliable and standardised and to classify the baby hip joint in accordance with their age.

During the examination, several angles of the hip anatomy are measured and stability of the hip can be assessed. The main objective of this technique is to recognise possible dysplasia as early as possible and prevent high exposure of the child to radiation.

Top tips for providing a Hip Service

1. Standard Ultrasound Technique for the assessment of DDH.

Grafs method including both hip morphology and stability has been shown to be feasible and accurate. It is highly recommended that all staff performing Ultrasound of hips attend Graf Ultrasound Hip course. Departments should have clear protocols and procedures and referral pathways for new-born’s with risk factors for DDH.

2. Technical Equipment

Use 5-7.5 or more MHz linear probes, no trapezoid or sector probes. Tilted probes or obliques scanning may lead to overdiagnoses. A baby positioning device to assist in keeping the baby in decubitus position should be used. To help reassure parents involve them in positioning and comforting the Baby during the scan

3. Examination of the Baby

At first, look to the lower limb of the os ilium, then rotate the probe into the correct plane.

After the anatomical identification, the image must be checked if it is in the correct plane? Ask yourself;

• Does it go through the middle of the acetabulum?  The lower limb of the os ilium in the fossa must be visible.
• Does it go through the middle of the acetabular roof?
• Are tilting or obliques planes avoided? Is the labrum visible?
• A plane needs 3 landmarks

4. Measurement mistakes

Remember:-Only images in the correct plane are accepted to be measured.

• the bone roof line is in contact with the bone and does not go through the bony rim automatically.
• the cartilage roof line comes from the bony rim ( this is a turning point from the concavity to the convexity) and not from the crossing point of the bony roof line and the acetabulum roof line. It goes through the middle of the Labrum and not to the top of the Labrum.

5. Standardise Report form.

Our Radiology Department in the Sandwell and West Birmingham Trusthave developed a standard template for reporting of DDH which helps all referrers/ clinicians read results.It includes indications, gestational age, clinical findings, Ultrasound findings for each hip separately and recommendations for further management.The information will allow for future research and auditing. Feedback from Clinicians are that the standardising of reports and the use of the template makes understanding of our reports simple for all multidisiclinary staff involved in the treatment of the Baby.

6. Multidisciplinary Team Meetings.

Building multidisciplinary relationships has been a key point in developing our service. Communication and team meetings with Orthopaedic Consultants and Paediatric Physiotherapists have improved our standards by identifying areas that need improving and discussing cases that may present as false-positives or false-negatives. It is important that scans are performed at the correct age and thus eliminating late treatment.

As Professor Graf would say “Better Hip scan today than a limp tomorrow”.