paediatric
Developmental Dysplasia of the Hip - Infant
advanced
6 min
28 marks
6 questions
Clinical Scenario
A 6-week-old female infant is referred by her GP for a 'hip click' detected at the newborn check. She was born at 38 weeks via breech presentation to a primiparous mother. The family history reveals a maternal aunt who had 'hip problems' as a baby. On examination, both hips are stable but you feel a subtle clunk on Ortolani testing of the left hip.
Coronal ultrasound image of infant hip demonstrating Graf Type IIc dysplasia. The alpha angle measures 48 degrees (normal >60 degrees) indicating deficient bony acetabular coverage. The beta angle is 65 degrees (normal <55 degrees) indicating increased cartilaginous coverage with displaced labrum. The femoral head is subluxed with poor containment. The iliac bone line, bony rim, and cartilaginous roof are annotated.
Image source: Open Access medical literature (NIH/PubMed Central) • CC-BY License
Questions
Question 1 (4 marks)
What are the risk factors for DDH and how do you clinically examine an infant's hip?
Question 2 (5 marks)
Interpret the ultrasound findings and explain the Graf classification system.
Question 3 (6 marks)
What is the role of screening and what imaging modalities are used at different ages?
Question 4 (5 marks)
Describe the Pavlik harness treatment including technique and monitoring.
Question 5 (4 marks)
What are the complications of Pavlik harness treatment?
Question 6 (4 marks)
When does Pavlik treatment fail and what are the next steps?
Exam Day Cheat Sheet
Must Mention
- •Graf classification (Type I-IV, alpha angle cutoffs)
- •Ortolani = reduction; Barlow = dislocation
- •Risk factors: breech, female, first-born, family history
- •Pavlik for <6 months, flexion 90-100°, abduction 50-60°
- •AVN = Pavlik disease (forced abduction)
- •Failure at 2-3 weeks → alternative treatment
Common Pitfalls
- •Confusing Ortolani/Barlow
- •Wrong Graf angles
- •Excessive Pavlik position
- •Prolonged failed Pavlik
- •USS after 6 months
- •Missing risk factors