Developmental dysplasia of the hip (DDH) refers to a spectrum of abnormalities that range in severity from mild instability to frank dislocation. The vast majority of clinical and anatomic hip abnormalities identified in early infancy resolve spontaneously.1 Left untreated, however, a hip that is persistently unstable and anatomically abnormal can lead to functional limitations, pain, and premature degenerative changes.2,3
Early detection of significant hip dysplasia allows for early intervention that is nonsurgical and likely to afford the best long-term outcome.2 Because DDH is asymptomatic until a child begins walking and occurs mostly in the absence of risk factors other than female sex, early identification relies on newborn screening and follow-up surveillance through physical examination and selective use of imaging studies.
In 2000, the American Academy of Pediatrics (AAP) issued its first clinical practice guideline on DDH and an accompanying technical report.4,5 Titled “Early detection of developmental dysplasia of the hip,” the guideline’s objective was to reduce the number of dislocated hips detected later in infancy and childhood, and it promoted screening as a primary care function.
In November 2016, the AAP released an updated clinical report titled “Evaluation and referral for developmental dysplasia of the hip in infants.”2 The 2016 clinical report was written to provide clinicians with literature-based direction on screening, surveillance, and referral for orthopedic consultation to prevent and/or detect a dislocated hip by 6 to 12 months of age in an otherwise healthy child. Developments providing impetus for the report included emerging evidence supporting observation rather than treatment of minor ultrasonographic hip variations, issuing of an “inconclusive” rating for the usefulness of DDH screening by the US Preventive Services Task Force (USPSTF), and release of an American Academy of Orthopaedic Surgeons (AAOS) evidence-based clinical practice guideline on DDH detection and management in infants aged 0 to 6 months.1,2,6
The AAP clinical report presents evidence and controversies surrounding diagnosis and management of DDH, and it contains 10 statements on best practices and state of the art that are based on literature review, expert opinion, policies and position statements of the AAP and the Pediatric Orthopaedic Society of North America (POSNA), and the AAOS clinical practice guideline.1,3,4 The guidance provided by the clinical report is mostly the same as that found in the AAP’s 2000 clinical practice guideline. The 2016 document differs, however, in its recommendations on risk factors that may prompt an imaging study.7 In addition, it brings forth the concept of hip-healthy methods of swaddling and includes a discussion of medicolegal risk to the pediatrician.
Practitioners are encouraged to read the entire clinical report on DDH. This article presents its recommendations with some related information.
The AAP promotes screening/surveillance physical examinations for DDH as a primary care function, and the clinical report notes that newborn and periodic surveillance are also endorsed by the POSNA, the Canadian DDH Task Force, and the AAOS.1-3,8
The clinical report addresses the controversial USPSTF “inconclusive”rating on the usefulness of DDH screening.6 In stating that “evidence is insufficient to recommend routine screening for DDH in infants as a means to prevent adverse outcomes,” the USPSTF noted that most hip abnormalities identified in newborns resolve spontaneously and that screening tests for DDH have limited accuracy. In addition, it cited risks of avascular necrosis resulting from surgical and nonsurgical interventions for DDH and psychological consequences or stresses accompanying early diagnosis and intervention as potential harms of screening. As reviewed in the clinical report, these concerns are negated by evidence from published studies that were not included in the USPSTF report.
Physical examination for DDH should be performed in newborns and at well-care child visits through age 9 months or until the child begins walking to detect significant hip dysplasia.
The Ortolani maneuver (Table 1), which elicits the sensation of a dislocated hip reducing, is considered the most important clinical test for detecting hip dysplasia in infants aged 0 to 3 months.2 After age 3 months, a reducible hip becomes stabilized in the dislocated position and limitation of abduction is considered the most reliable sign of DDH.4
The Barlow maneuver (Table 1), which involves gentle adduction to produce subluxation or dislocation of a reduced femoral head, is another test for assessing hip instability in newborns. The Barlow maneuver, however, only identifies laxity or instability and it is considered to be less clinically significant than the Ortolani maneuver. As explained in the clinical report, mild hip instability may represent normal developmental variation, and hips that are Barlow-positive in the first few weeks of life resolve spontaneously.
The physical examination for DDH should also look for unequal leg length and asymmetry in the position or number of thigh and/or buttock (gluteal) creases. Examiners should be aware, however, that leg length discrepancy may be absent when DDH is bilateral, which occurs in up to 37% of affected cases.9,10 In addition, asymmetry of skinfolds is a nonspecific and common finding in infants.11