Developmental Dysplasia of the Hip

Question 1

Risk factors of DDH

Answer 1

• Genetic - Defect in transforming growth factor beta superfamily necessary for bone and joint development.
• Female
• Breech delivery
• Family history
• Tight swaddling of lower limbs in extension and adduction.

Question 2

Reasons of importance for early detection of DDH

Answer 2

• Hip maturation greatest during 1st 6 weeks of life and plateaus by end of 3/12.
• Brace treatment has 4x higher failure rate if commenced after 7/52.

Question 3

Describe the Ortolani Test

Answer 3

• Place settled baby on firm surface.
• Flex and adduct hips
• Abduct with gentle traction and pressure on the greater trochanter
• A dislocated hip relocates with a ‘clunk’
• Finds hips that are dislocated at rest and relocates after test

Question 4

Describe the Barlow Test

Answer 4

• Hip is adducted and pressure relieved from the greater trochanter
• Gentle posterior force will cause a disclocatable hip to slip out of posterior acetabulum
• Finds hips that are in place at rest and dislocates after test

Question 5

How to diagnose a Barlow and Ortolani -‘ve Hip dysplasia

Answer 5

• Joint does neither dislocate (already dislocated) or relocate.
• Review possibility by abducting both hips so that lateral surface of knees contacts examination surface.
• If unable to, consider urgent US to confirm irreducible dislocation

Question 6

DDH Examination techniques

Answer 6

• Barlow Test
• Ortolani Test
• Assessment for asymmetrical thigh and gluteal skin folds
• Abduct both hips to have lateral aspect of knees contact examination surface

Question 7

Late detection signs of DDH in a walking child

Answer 7

• Leg length discrepancy
• Decreased abduction
• Unilateral toe walking
• Limp

Question 8

Imaging modalities for DDH based on age

Answer 8

0 - 4/12 - US
4/12 - 6/12 - Either US or Xray
>6/12 - Xray