ORTHOPEDICS: More hip dysplasia questions than answers

Part of Contemporary Pediatrics’ coverage of the 2015 AAP Annual Conference. For more coverage, click here.

With heated debate surrounding the very definition of developmental dysplasia of the hip (DDH), said Brian A Shaw, MD, FAAP, FAAOS, this topic yields more unanswered questions today than it did over a decade ago. The presentation by Lee Segal, MD, and him “Clicks and Clunks: Staying Out of Trouble with Infant Hips,” emphasized that, because failure to diagnose or manage DDH ranks among the most common causes of lawsuits against pediatricians, every step toward clarity helps.

According to an exhaustive literature review performed by the American Academy of Orthopaedic Surgeons (AAOS), fewer than 2% of DDH studies had evidence of high enough quality to draw firm conclusions.¹ Not surprisingly, we have huge gaps in our knowledge of what hip dysplasia is and its natural history. The DDH literature is generally difficult to interpret and apply because there has been no definition agreed on for the term nationally or internationally.

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One factor behind the variability of definitions is the fact that advances in ultrasound technology-the ability to visualize the hip statically or dynamically-have outstripped our ability to interpret the significance of those findings. Segal said that over time and with high-quality studies, answers such as whom to treat, when to intervene, length of treatment, and consensus of treatment recommendations hopefully will evolve.

Presently, pediatricians and lawyers should know that there is no study-even in countries that support universal ultrasound screening (which the American Academy of Pediatrics and AAOS do not support)-showing that the condition can be eliminated. No matter how careful a pediatrician may be, the expectation should not be perfection. Developmental dysplasia of the hip can develop after birth, even as late as the adolescent years.

That’s why we don’t like the term “screening.” We prefer the term “hip surveillance,” said Shaw.² Screening implies a clear-cut positive or negative result. Hip dysplasia is rarely clearly negative or positive. It covers a broad spectrum of pathophysiology ranging from normal to very abnormal, with a large gray zone in between.

Perhaps the clearest recommendations that can be made presently are these:

·      Examine infant hips at every appointment during the first year of life.

·      Accurately document findings on physical examinations.

·      Selectively image “high-risk” hips (breech, positive family history).

·      Disabuse parents of improper swaddling practices.

The only way to prevent hip problems in neonates is to teach parents and caretakers that if they must swaddle, avoid the extended, adducted hip position that results from swaddling legs too tightly.

Brian A Shaw, MD, FAAP, FAAOS, is an associate professor of orthopedic surgery, University of Colorado, Children’s Hospital Colorado, Colorado Springs.

Lee Segal, MD, is a clinical investigator, orthopedic surgery, SUNY Upstate Medical Center, Syracuse, New York.

References

1. American Academy of Orthopaedic Surgeons. Detection and nonoperative management of pediatric developmental dysplasia of the hip in infants up to six months of age: evidence-based clinical practice guideline. September 5, 2014. www.aaos.org/research/guidelines/DDHGuidelineFINAL.pdf. Accessed October 5, 2015.

2. Clarke NM, Reading IC, Corbin C, et al. Twenty years experience of selective secondary ultrasound screening for congenital dislocation of the hip. Arch Dis Child. 2012;97(5):423-429.

NEXT: Commentary and the need for more evidence

Commentary

Developmental dysplasia of the hip comprises a broad spectrum of disorders; can be difficult to detect; and is a common cause of legal actions against pediatricians for failure to diagnose. The identification of risk factors warranting consideration of imaging is probably the most important aspect presented by Drs Shaw and Segal. Even in the best of hands, the physical examination will not be able to detect DDH and will not eliminate late detection.

Additionally, the presentation clearly expresses that the level of evidence for DDH studies is very low. This makes it impossible to make any strong recommendations for the screening of children with DDH.

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Previously, the name of this condition was changed from CDH (congenital dislocation of the hip) to DDH to emphasize that the disorder may not be present at birth but evolve over time. It was hoped that this would decrease the lawsuits against pediatricians for the “missed” diagnosis of hip dysplasia, because the prior name implied that it was present at birth and, if detected late, was obviously missed by someone. The name change appears not to have helped substantially.

The US Preventive Services Task Force reviewed the evidence in DDH and found no evidence that screening prevents adverse outcomes. When DDH is detected, it is not possible to determine whether it was present at birth or occurred later. Although there is evidence that nonoperative treatment can be successful, there is no evidence that early detection and treatment will lead to an improved result for any specific patient. We do not know the results of treatment compared to the natural history. Plaintiffs’ attorneys make the assumption that late diagnosis results in worse results than early diagnosis and treatment for a specific patient. We actually have no evidence that this is the case.

James O Sanders, MD, is a professor of orthopedics and pediatrics, University of Rochester Golisano Children’s Hospital at Strong Memorial, New York.