The American Academy of Pediatrics does not recommend routine ultrasounds for every infant. But for babies with an abnormal physical exam or major risk factors for developmental dysplasia of the hip, or DDH, (family history, Breech position etc.) the AAP supports referral for ultrasound and/or pediatric orthopedic consultation.
What is an abnormal physical exam?
- The most concerning physical exam finding is the classic Ortolani sign — the hip is felt to “clunk” into place with abduction of the hip.
- A Barlow sign — when the hip slides out of the socket with posteriorly directed force — also indicates risk of DDH.
- Mild laxity of the hip may be physiologic within the first 4-6 weeks of life but is abnormal if it persists much beyond that point.
- Decreased abduction is also a concerning finding, especially in older children in whom it is uncommon to feel a Ortolani or Barlow sign due to tightening of the hip musculature.
Remember: Asymmetric thigh folds are a very unreliable indicator of DDH, and a simple hip click may or may not be associated with a problem.
If the exam is normal, but the infant has risk factors for DDH, when should I order an ultrasound?
If the hip feels normal but risk factors for DDH are present, CHOP orthopedists recommend that screening ultrasounds be performed at 4-6 weeks of age. Ordering ultrasounds for a child younger than 4 weeks can lead to false positive results. The US may reveal mild dysplasia that can spontaneously resolve after a few weeks of life.
When should I order an X-ray, rather than an ultrasound, to diagnose a musculoskeletal problem in an infant?
Ultrasounds are the diagnostic method of choice for infants under 6 months of age. Around 6 months of age, enough bone is present in an infant hip to make an X-ray more accurate than ultrasound.
If I suspect DDH in a baby, when should I refer to a pediatric orthopedist?
Any child of any age with an Ortolani or Barlow sign should be referred to a pediatric orthopedist for evaluation. Similarly, any child that has persistent laxity beyond 6 weeks of age should also be referred. For children with normal physical exams, referral is warranted for any child with dysplasia (or shallowness of the hip joint) beyond 6 weeks of age. But any time you are concerned about a child, we are happy to evaluate the patient and can typically arrange a visit with a hip specialist within a few days.
What’s new in DDH treatment?
The Pavlik harness remains the mainstay of treatment for most infants with DDH. Recently, CHOP has pioneered the use of alternative braces for those infants who fail harness treatment, which has decreased the need for surgery. For infants who do require surgical intervention, CHOP is one of the few centers in the country that offers state-of-the-art perfusion MRI imaging after cast placement which has drastically reduced the risk of avascular necrosis — the most concerning complication of DDH treatment.
Where can I direct my patients for more information?
Many families who you refer to our center for consultation will ask for some initial information. A great place to point families to is www.hipdysplasia.org, a website developed by the International Hip Dysplasia Institute. This organization is dedicated to education and research about DDH. Investigators at CHOP serve on the medical advisory board for the organization (a non-financial relationship).