“Normal” Ultrasound May Not Rule Out DDH Later in Childhood
Some years ago, we moved away from calling hip dysplasia “congenital” and started using the term “developmental dysplasia of the hip” (DDH). Indeed, it is developmental. As a surgeon specializing in pediatric orthopaedics and hip preservation, I see not only infants when DDH is of potential concern but also young adults with more mature manifestations of hip dysplasia not previously diagnosed or treated.
Screening protocols have successfully helped in the early identification of DDH and dislocation, but what is the likelihood that infants with risk factors for dysplasia but normal ultrasound results will go on to experience DDH in childhood? And which risk factors are predictive?
In a recent report in JBJS Open Access, Humphry et al. provide new insight into these challenging questions. This study from the UK included 1,053 children from a cohort of 2,191 children who had been assessed as newborns and had at least 1 of 9 perinatal risk factors for DDH. All had undergone ultrasound at a mean of 8 weeks and were followed clinically.
The mean age of the children in the current study was 4.4 years (range, 2.0 to 6.6 years). Thirty-seven of the participants had been treated for DDH in the postnatal period, predominantly with a harness.
Assessing the acetabular index (AI) on pelvic radiographs, the authors found that:
- 27 of the children had “severe” hip dysplasia (an AI of >2 standard deviations above age and sex reference values). Girls were more likely to have this outcome. Only 3 of the 27 received treatment for DDH in infancy.
- 146 (13.9%) of the children had an AI of >20°, only 12 of whom had been treated during infancy; 92% had no prior diagnosis of DDH. On multivariate analysis, female sex and breech presentation at birth were significantly predictive of this “mild” dysplasia (breech presentation demonstrated a nearly twofold increased odds of an AI of >20° at ≥3 years of age), while first-born status had a protective effect.
The findings of this study lend support to radiographic monitoring later in childhood for patients with risk factors such as breech positioning at birth. While the exact algorithm of ultrasound and radiographic workup still needs to be elucidated, it appears that a “normal” ultrasound in infancy does not necessarily rule out the development of hip dysplasia in children with select risk factors.
Matthew R. Schmitz, MD
JBJS Deputy Editor for Social Media
Treating Developmental Hip Dislocations Diagnosed after Walking Age
There is a wry saying in academic medicine that “nothing ruins good results like long-term follow-up.” But long-term follow-up helps us truly understand how our orthopaedic interventions affect patients. This is especially important with procedures on children, and the orthopaedic surgeons at the University of Iowa have been masterful with long-term outcome analysis in pediatric orthopaedics. They demonstrate that again in the August 5, 2020 issue of The Journal, as Scott et al. present their results comparing outcomes among 2 cohorts of patients who underwent treatment for developmental hip dislocations between the ages of 18 months and 5 years—and who were followed for a minimum of 40 years.
Seventy-eight hips in 58 patients underwent open reduction with Salter innominate osteotomy, and 58 hips in 45 patients were treated with closed reduction. At 48 years after reduction, 29 (50%) of the hips in the closed reduction cohort had undergone total hip arthroplasty (THA), compared to 24 (31%) of hips in the open reduction + osteotomy group. This rate of progression to THA nearly doubled compared to previously reported results at 40 years of follow-up, when 29% of hips in the closed reduction group and 14% of hips in the open reduction group had been replaced.
In addition, the authors found that patient age at the time of reduction and presence of unilateral or bilateral disease affected outcomes. Patients with bilateral disease who were treated at 18 months of age had a much lower rate of progression to THA when treated with closed reduction, compared to those treated with open reduction—but the opposite was true among patients with bilateral disease treated at 36 months of age. Treatment type and age did not seem to substantially affect hip survival among those with unilateral disease.
I commend the authors for their dedication to analyzing truly long-term follow-up data to help us understand treatment outcomes among late-diagnosed developmental hip dislocations in kids. Long-term follow-up may “ruin” good results, but it gives us more accurate and useful results. And, in this case, the findings reminded us how important it is to diagnose and treat developmental hip dislocations as early in a child’s life as possible.
Read the JBJS Clinical Summary about this topic.
Matthew R. Schmitz, MD
JBJS Deputy Editor for Social Media
Choosing Wisely Now Addresses Pediatric Orthopaedics
OrthoBuzz occasionally receives posts from guest bloggers. This guest post comes from Matthew R. Schmitz, MD, a member of the JBJS Social Media Advisory Board.
The American Academy of Pediatrics (AAP) Section on Orthopaedics and the Pediatric Orthopaedic Society of North America (POSNA) recently issued a list of tests and treatments that physicians and patients should avoid. The list appears on the Choosing Wisely® website, an initiative of the American Board of Internal Medicine (ABIM) Foundation.
The list highlights 5 commonly encountered pediatric orthopaedic scenarios/conditions that often consume excessive time and resources with little or no clinical value in return. The Evidence Based Committee and Advocacy Committee of POSNA developed the peer-reviewed list and vetted it through both the POSNA Board of Directors and the AAP Executive Committee.
Although geared toward family and primary care physicians, the list contains important take-home points for orthopaedic surgeons who might have pediatric patients walk through their doors. The recommendations include the following:
- Screening ultrasound for developmental hip dysplasia is not needed if the newborn has no risk factors and has a clinically stable hip exam. The substantial rate of false positives with screening ultrasounds likely causes many children to undergo unnecessary treatment.
- Simple in-toeing does not require a radiographic workup or brace or surgical treatment in children younger than 8 years old. Unless there is severe tripping, falling, or marked asymmetry, a watchful waiting approach is best for this condition, which typically resolves with growth.
- Custom orthotics or shoe inserts are not needed for children with asymptomatic or minimally symptomatic flat feet. If the flatfoot is minimally symptomatic and flexible (arch reconstitutes when the child stands on his/her toes), it can be managed with observation or over-the-counter orthotics.
- Advanced imaging such as MRI or CT should not be ordered for most musculoskeletal conditions in children until all appropriate clinical, laboratory, and plain film examinations have been done. Most pediatric conditions can be accurately diagnosed with a good history, physical exam, plain radiographs, and occasional labs. Use advanced imaging only if a specific question arises from the preceding workup. CT scans expose patients to high levels of radiation and should be used judiciously. If MRI is deemed necessary, it is best to have the consulting orthopaedist order the MRI with specific protocols and sequences.
- Buckle fractures do not need follow-up radiographs if pain and tenderness have resolved after immobilization. These common pediatric injuries are inherently stable.
Both POSNA and the AAP should be commended on their evidenced-based and common-sense approach for tackling these common pediatric orthopaedic conditions.
Matthew R. Schmitz, MD is vice chair of the Department of Orthopaedics and chief of Pediatric Orthopaedics and Adolescent Sports Medicine at San Antonio Military Medical Center in Ft. Sam Houston, Texas.
Don’t Delay DDH Treatment to Wait for Ossific Nucleus
The exact cause of osteonecrosis in the setting of developmental dysplasia of the hip (DDH) is unknown. However, some pediatric orthopaedists are concerned that DDH treatment in the absence of the ossific nucleus of the femoral head increases the risk of subsequent osteonecrosis. That concern has to be weighed against evidence that delayed DDH treatment may lead to more difficult reduction and potentially necessitate additional procedures.
In the May 3, 2017 issue of JBJS, Chen et al. performed a meta-analysis of cohort and case-control studies to clarify this potential “conflict of interests” in DDH treatment. Twenty-one observational studies were included. Of the 969 hips with an ossific nucleus present before reduction, 198 hips (20.4%) had eventual osteonecrosis events; among the 608 hips without an ossific nucleus, 129 (21.2%) had osteonecrosis events. The authors state that this difference “is neither clinically important nor [statistically] significant.”
A sub-analysis determined that the presence of the ossific nucleus was not associated with significantly decreased odds of osteonecrosis even among patients who later developed more severe (grades II to IV) osteonecrosis. Chen et al. also performed a “meta-regression” of studies with short- and long-term follow-ups, finding “no evidence for a protective effect of the ossific nucleus with either short or long-term follow-up.”
Although 11 of the 21 studies in the meta-analysis were deemed high quality and 10 were of moderate quality, the inherent limitations of a meta-analysis derived predominantly from retrospective data prompted the authors to call for “further prospective studies with long-term follow-up and blinded outcome assessors.” Nevertheless, these findings lend additional support to the belief that treatment for DDH should not be delayed based on the absence of the femoral head ossific nucleus.
What’s New in Pediatric Orthopaedics
Every month, JBJS publishes a Specialty Update—a review of the most pertinent and impactful studies published in the orthopaedic literature during the previous year in 13 subspecialties. Click here for a collection of all OrthoBuzz Specialty Update summaries.
This month, Derek Kelly, MD, co-author of the February 15, 2017 Specialty Update on Pediatric Orthopaedics, selected the five most clinically compelling findings from among the 60 studies summarized in the Specialty Update.
Upper-Extremity Trauma
—A systematic review of eight randomized studies comparing splinting with casting for distal radial buckle fractures confirmed that splinting was superior in function, cost, and convenience, without an increased complication rate.1
Lower-Extremity Trauma
—A review of the treatment of 361 pediatric diaphyseal femoral fractures before and after the 2009 publication of AAOS clinical guidelines for treating such fractures revealed that the guidance had little impact on the treatment algorithm in one pediatric hospital.
Spine
—Bracing remains an integral part of managing adolescent idiopathic scoliosis, but patient compliance with brace wear is variable. A prospective study of 220 patients demonstrated that physician counseling based on compliance-monitoring data from sensors embedded in the brace improved patients’ average daily orthotic use.
Hip
—AAOS-published evidence-based guidelines on the detection and nonoperative management of developmental dysplasia of the hip (DDH) in infants from birth to 6 months of age determined that only two of nine recommendations gleaned from evidence in existing literature could be rated as “moderate” in strength:
- Universal DDH screening of all newborn infants is not supported.
- Imaging before 6 months is supported if the infant has one or more of three listed risk factors.
Seven additional recommendations received only “limited” strength of support.
—A study of the utility of inserting an intraoperative intracranial pressure (ICP) monitor during closed reduction and pinning for slipped capital femoral epiphysis (SCFE) found that 6 of 15 unstable hips had no perfusion according to ICP monitoring. However, all 6 hips were subsequently reperfused with percutaneous capsular decompression, and no osteonecrosis developed over the next 2 years.
Reference
- Hill CE, Masters JP, Perry DC. A systematic review of alternative splinting versus complete plaster casts for the management of childhood buckle fractures of the wrist. J Pediatr Orthop B. 2016 ;25(2):183–90.
DDH Webinar Tomorrow—CME Available
Treating developmental dysplasia of the hip (DDH) with the Pavlik harness is safe and successful in about 90% of cases. But what about the 10% of patients for whom this treatment is not effective or causes complications The complimentary JBJS webinar on Wednesday, Feb. 24, 2016 at 8:00 PM EST will focus on how orthopaedists can:
- Identify patient characteristics that help predict Pavlik harness failure
- Understand the role of ultrasound in managing DDH
- Recognize and prevent complications from using the harness
- Successfully treat patients who need a post-Pavlik approach
Following presentations about JBJS-published research by Daniel Sucato, MD; Lucas Murnaghan, MD; and Wudbhav Sankar, MD, DDH expert Scott Mubarak, MD will expand on all three author presentations. The last 15 minutes of the webinar will be devoted to a live Q&A session, during which audience members can ask questions of the authors and commentator. The webinar will be moderated by Paul Sponseller, MD.
CME Credit Available
For those who attend this activity live, The Journal of Bone and Joint Surgery Inc. designates this webinar for a maximum of 1 AMA PRA Category 1 Credits™. The Journal of Bone and Joint Surgery Inc. is accredited by the Accreditation Council for Continuing Medical Education (ACCME) to provide continuing medical education for physicians.
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