The clinical practice guideline (CPG) for “Management of Detection and Nonoperative Management of Pediatric Developmental Dysplasia of the Hip (DDH) in Infants Up to Six Months of Age” helps clarify the criteria for determining which patients should be screened and when (Table 1). The two most significant recommendations, each categorized as Moderate in strength in terms of supporting evidence, offer the following guidance:
- Evidence does not support universal ultrasound screening of newborn infants.
- Evidence supports performing an imaging study before 6 months of age in infants with one or more of the following risk factors: breech presentation, family history, or history of clinical instability.
CPGs characterize evidence as Strong, Moderate, Limited, or Consensus. Moderate evidence is that derived from two or more Moderate strength studies with consistent findings, or evidence from a single High quality study for recommending for or against the intervention. A Moderate recommendation means that the benefits exceed the potential harm (or that the potential harm clearly exceeds the benefits in the case of a negative recommendation), but the quality/applicability of the supporting evidence is not as strong.
Strong evidence is evidence from two or more High strength studies with consistent findings for recommending for or against the intervention.
In addition to the two Moderate recommendations, the DDH CPG offers the following seven recommendations backed by Limited evidence:
- The use of an ultrasound study to guide the decision to initiate brace treatment in infants younger than 6 weeks of age with a positive instability examination (Fig. 1)
- The use of an AP pelvis radiograph instead of an ultrasound to assess DDH in infants beginning at 4 months of age
- Repeat examination of infants previously screened as having a normal hip examination on subsequent visits prior to 6 months of age
- Observation without a brace for infants with a clinically stable hip and morphologic ultrasound imaging abnormalities
- Either immediate or delayed (2 to 9 weeks) brace treatment for hips with a positive instability exam
- Use of the von Rosen splint rather than the Pavlik, Craig, or Frejka splints for initial treatment of an unstable hip
- Performance of serial physical examinations and periodic imaging assessments (ultrasound or radiograph, based on age) during management for unstable infant hips
The need for screening
Kishore Mulpuri, MD, of BC Children’s Hospital, British Columbia, Canada, is work group chair for the DDH Guideline. Addressing the screening recommendations, he said, “Only limited evidence shows that ultrasound is useful in diagnosing DDH in children younger than 6 months of age. If the child presents with DDH symptoms, the hip needs to be evaluated with an imaging examination.”
He noted that current standards and practices for screening vary. “Some centers—particularly in Europe—use universal ultrasound,” he said. “But universal ultrasound is probably overdiagnosis and overtreatment. The guideline looked at what the literature shows are the appropriate risk factors. Basically, the recommendation is for a universal clinical exam, followed by a selective ultrasound exam.
“This guideline provides some clarity,” he continued. “If a pediatrician or a family doctor calls about what needs to be done, the orthopaedic surgeon can now say, ‘Everybody gets a clinical exam, and then selected infants get an ultrasound study.’”
“There is a widely held public perception that screening and early detection of DDH is a good thing, and the CPG does not refute this,” said Kit Song, MD, vice chair of the DDH work group. However, he said, “more research is needed to better define who needs treatment and what that treatment should be.”
Dr. Mulpuri noted that the guidelines received the endorsement of the Society of Diagnostic Medical Sonography, the Society of Pediatric Radiology (SPR), and the Pediatric Orthopaedic Society of North America (POSNA). In addition to these groups, members of the American Academy of Pediatrics and the American Academy of Family Physicians served on the work group.
“This guideline will be used by family doctors and pediatricians. Many places don’t have a pediatric orthopaedic surgeon. In these situations, pediatricians are screening and actually managing the course of treatment,” he said. “This CPG affects potentially every child who is born. Now we can actually point to what the literature says is the best way to screen these children.”
Dr. Mulpuri described the treatment scenario for patients who have been diagnosed clinically or by initial imaging, as suggested by the guideline recommendations.
“The orthopaedic surgeon is following up, or is seeing the patient for the first time because someone saw a problem with range of motion in the hip or other abnormality and referred the patient. Beginning when the infant is about 4 months old, the orthopaedist would switch from ultrasound to radiographs,” he said. “There is ambiguity. At some centers, the ultrasound limit is 6 months, and at other centers, radiographs are taken at 2 months. Unfortunately, the literature does not give a definitive answer, but limited evidence indicates that plain radiographs should be reviewed at 4 months.”
Bracing: When and what kind?
Dr. Mulpuri observed that “huge variability” exists in the matter of when to use a brace and what kind of brace to use. Some practitioners routinely prescribe bracing for patients with any signs or symptoms.
“We need better evidence,” he said. “If a minor imaging abnormality is noted, the natural history would suggest that, over time, a significant portion of these abnormalities would resolve. We hope for better indications on how to proceed, to see just how many would resolve.”
The decision of whether to use a rigid or soft appliance is guided only by evidence from retrospective studies. Evidence is similarly spotty regarding monitoring of patients during brace wear.
“Monitoring can add cost and radiation,” said Dr. Mulpuri. “Some physicians would do weekly ultrasounds; others would only do two—at initiation of treatment and at the end. We weren’t able to give a clear guideline on how children should be monitored.”
Dr. Mulpuri said the effort to gather stronger evidence to guide treatment decisions will continue. “We, as orthopaedic surgeons, need to work together to improve the evidence,” he said, “so that when we revisit these guidelines in 5 years, we will have better evidence to show for those recommendations.”
The full guideline, “Management of Detection and Nonoperative Management of Pediatric Developmental Dysplasia of the Hip (DDH) in Infants Up to Six Months of Age,” can be accessed at www.aaos.org/guidelines
Terry Stanton is a senior science writer for AAOS Now. He can be reached at email@example.com