Screening for developmental dysplasia of the hip: an evidence-based approach to practice

Dr. Kishore Mulpuri, MBBS, MS (Ortho), MHSc (Epi) (biography and disclosures)
Disclosures: Receives research support in the form of grant funding from Depuy, Johnson & Johnson. Currently participating in a multi-centre, prospective observational study of infants with hips dislocated at rest by the International Hip Dysplasia Institute (IHDI). No conflict of interest: Depuy, Johnson & Johnson funding support is for studies unrelated to this article. This article has been based on published recommendations and guidelines and don’t incorporate findings from the ongoing IHDI study. Mitigating Potential Bias: Recommendations are consistent with published guidelines by the AAOS: The detection and non-operative management of developmental dysplasia of the hip in infants up to six months of age: evidence-based guideline and evidence report.

What care gaps or frequently asked questions have I noticed?

Developmental Dysplasia of the Hip (DDH) is a spectrum of hip joint abnormalities ranging from mild dysplasia to severe, frank dislocations.^1-3 Left untreated, DDH can lead to serious complications later in life including osteoarthritis of the hip and total hip replacement. DDH is the most common pediatric hip disorder, but its true incidence has been difficult to quantify due to significant variations in diagnostic criteria and inconsistent terminology used throughout the literature to describe hip abnormalities. Recently, the American Academy of Orthopaedic Surgeons (AAOS) published their clinical practice guideline (CPG), Detection and Nonoperative Management of Pediatric Developmental Dysplasia of the Hip (DDH) in Infants up to Six Months of Age, following a rigorous, standardized methodological review of the evidence existing in the literature.⁴ This guideline provided nine recommendations for the screening and treatment of DDH; however, only two of these recommendations were of moderate strength, while the other recommendations were of limited strength based upon the quality of evidence available.

These findings highlighted the care gaps and outstanding questions I frequently see in my practice. First, the method of screening for DDH in infants is highly debated, with some countries and institutions adopting a universal ultrasound screening policy for newborns and others adopting a selective ultrasound screening method based upon risk factors.⁵ The standard diagnosis procedure remains the clinical examination; however, not all cases are detectable by this method. As a result, pediatric orthopaedic surgeons have different opinions on optimal ultrasound usage, even among those practicing at British Columbia Children’s Hospital. Second, the optimal time to treat clinically or radiographically diagnosed DDH is unclear. Bracing (orthosis) is the primary nonoperative method to treat and manage DDH in infants. However, natural history studies have found that 60-80% of clinically identified hip abnormalities and 90% of ultrasonographic abnormalities spontaneously resolved without treatment in early infancy.^6-8 This has led to considerable variation in brace treatment timing, based on the practitioner’s discretion. Third, there are multiple brace types available for DDH treatment, with distinct complications associated for each. Consequently, there is no standardized practice for either diagnosis or management of DDH.

Data that Answers these Questions or Gaps

The limited strength of the AAOS recommendations clearly demonstrates the substantive work that remains to be done to strengthen the existing evidence in support of DDH detection and management. However, the guideline also presented some data that helps to answer the gaps in care for this condition. In regards to screening and detection of DDH, moderate evidence suggests universal ultrasound screening of newborn infants is not necessary, and may instead lead to overtreatment in cases that would have spontaneously resolved. Two moderate strength studies demonstrated no statistical difference between universal and selective ultrasound screening; therefore, the considerable diagnostic and therapeutic effort and resource commitment required for universal screening would not significantly impact the prevalence of late-diagnosed cases.^9,10 Instead, there is evidence to support performing selective imaging before six months of age in infants with at least one of the following risk factors: breech presentation, family history or history of clinical instability. Two moderate strength studies confirmed a significant relationship between selective prospective ultrasound screening and preventing late dislocations in infants with a history of clinical instability and/or risk factors of breech presentation and family history.^11,12 This relationship was not observed with other previously cited risk factors such as foot abnormalities, gender, oligohydramnios and torticollis.

Deciding when to treat a patient, there is conflicting evidence about whether an observation period or immediate brace treatment leads to a difference in later dysplasia or persistent hip instability following a positive hip instability exam. Several studies examined radiographic differences between early and late brace treatment groups. While one study found a significant improvement in radiographic outcomes at 15 months in the immediate treatment group compared to the two-week delayed group¹³, another study found no significant outcome differences when treatment started at less than one week versus after nine weeks.¹⁴ Consequently, there is evidence to support either action at the practitioner’s discretion on a patient-by-patient basis.

Finally once deciding to treat, there are no high quality comparative effectiveness studies between different braces for DDH treatment. Two low-strength studies do suggest potential increased effectiveness of rigid versus soft bracing;^15,16 however, potential harms include incidence of skin irritation with the rigid brace, and avascular necrosis (AVN) of the femoral head with all forms of bracing.

What I recommend (Practice Tip)

Based on the recent guidelines and the existing evidence, I recommend supplementing the clinical exam administered to all newborns with selected ultrasound screening of those infants with a history of clinical instability, breech presentation or family history. This practice should help identify and target an at-risk population for careful screening, while avoiding overtreatment and expending significant, potentially unnecessary resources. This ultrasound screening of at-risk infants should be performed when it is most reliable – around 6 weeks of age and before 4 months – to prevent possible complications should the need for treatment arise.¹⁷ Anytime after 4 months of age, screening for DDH should be performed using a radiograph of both hips and the pelvis.

Additionally, given the limited evidence to support either immediate or delayed (2-9 weeks) brace treatment for hips with a positive instability exam, either course of action could be appropriate. The evidence suggests that delaying treatment up to nine weeks should not negatively impact patient outcome, and may allow for the spontaneous resolution of symptoms prior to initiating any treatment. Such decisions should be at the practitioner’s discretion on a patient-by-patient basis.

Finally, the development of the AAOS guidelines for DDH served to emphasize the need to strengthen the existing evidence in order to provide the best treatment recommendations to guide the practicing physician. A concerted and collaborative research effort among the orthopaedic surgeon community will be required to improve the evidence and strengthen the current recommendations. This goal can be accomplished through the implementation of more prospective study groups and clinical trials as opposed to relying on retrospective analysis of existing data. Prospective studies will foster multi-centre collaborative data collection to aid in the identification of best practices and development of standardized diagnosis and treatment methods for DDH (www.hipdysplasia.org).

Acknowledgement

I would like to thank Emily Schaeffer for her help in putting this article together.

Resources:

1. For physicians: education module including hip examination: http://hipdysplasia.org/for-physicians/pediatricians-and-primary-care-providers/lectures-and-videos/
2. For patients: video on hip healthy swaddling: http://hipdysplasia.org/developmental-dysplasia-of-the-hip/hip-healthy-swaddling/

References

1. Aronsson, DD, Goldberg MJ, Kling TF, et al. Developmental dysplasia of the hip. Pediatrics 1994; 94(2 pt 1):201-8. (View with CPSBC or UBC)
2. Wright JG, Swiontkowski MF, Heckman JD. Introducing levels of evidence to the journal. J Bone Joint Surg Am. 2003; 85(1):1-3. (Request with CPSBC or view with UBC)
3. Balshem H, Helfand M, Schunemann HJ, et al. GRADE guidelines: 3. Rating the quality of evidence. J Clin Epidemiol. 2011; 64(4):401-6. (View with CPSBC or UBC)
4. American Academy of Orthopaedic Surgeons: Detection and Nonoperative Management of Pediatric Developmental Dysplasia of the Hip in Infants up to Six Months of Age.
   J Am Acad Orthoped Surg. 2015; 23(3):202-205. (View with CPSBC or UBC)
5. Mahan ST, Katz JM, Kim YJ. To screen or not to screen? A decision analysis of the utility of screening for developmental dysplasia of the hip. J Bone Joint Surg Am. 2009; 91(7): 1705-1719. (View with CPSBC or UBC)
6. Castelein RM et al. Natural history of ultrasound hip abnormalities in clinically normal newborns. J Pediatr Orthop. 1992; 12(4):423-7. (Request with CPSBC or view with UBC)
7. Tegnander A, Holen KJ, Terjesen T. The natural history of hip abnormalities detected by ultrasound in clinically normal newborns: a 6-8 year radiographic follow-up study of 93 children. Acta Orthop Scand. 1999; 70(4):335-7. (View with CPSBC or UBC)
8. Chen HW, et al. Natural progression of hip dysplasia in newborns: a reflection of hip ultrasonographic screenings in newborn nurseries. J Pediatr Orthop B. 2010; 19(5):418-23.  (View with CPSBC or UBC)
9. Holen KJ, Tegnander A, Bredland T, et al. Universal or selective screening of the neonatal hip using ultrasound? J Bone Joint Surg Br. 2002; 84(6):886-890. Free full text
10. Rosendahl K, Markestad T, Lie RT. Ultrasound screening for developmental dysplasia of the hip in the neonate: the effect on treatment rate and prevalence of late cases. 1994; 94(1):47-52. Missing journal name:  Pediatrics. (Request with CPSBC or view with UBC)
11. Paton RW, Hinduja K, Thomas CD. The significance of at-risk factors in ultrasound surveillance of developmental dysplasia of the hip. A ten-year prospective study. J Bone Joint Surg Br. 2005; 87(9):1264-6. Free full text
12. Paton RW, Srinivasan MS, Shah B, Hollis S. Ultrasound screening for hips at risk in developmental dysplasia. Is it worth it? J Bone Joint Surg Br. 1999; 81(2):255-8. Free full text
13. Molto LFJ, Gregori AM, Casas LM, Perales VM. Three-year prospective study of developmental dysplasia of the hip at birth: should all dislocated or dislocatable hips be treated? J Pediatr Orthop. 2002; 22(5):613-21. (View with CPSBC or UBC)
14. Paton RW, Hopgood PJ, Eccles K. Instability of the neonatal hip: the role of early or late splintage. Int Orthop. 2004; 28(5):270-73. Free full text
15. Heikkila E. Comparison of the Frejka pillow and the von Rosen splint in treatment of congenital dislocation of the hip. J Pediatr Orthop. 1988; 8(1):20-21. (Request with CPSBC or view with UBC)
16. Wilkinson AG, Sherlock DA, Murray GD. The efficacy of the Pavlik harness, the Craig splint and the von Rosen splint in the management of neonatal dysplasia of the hip. A comparative study. J Bone Joint Surg Br. 2002; 84(5):716-19. Free full text
17. Riad JP, Cundy P, Gent RJ, Piotto L, Morris L, Hirte C. Longitudinal study of normal hip development by ultrasound. J Pediatr Orthop. 2005; 25(1):5-9. (View with CPSBC or UBC)

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