Paediatric Orthopaedics

Question 1

What is developmental dysplasia of the hip?

Answer 1

• Failure of normal hip development (seating of femoral head and moulding of joint around it)
• It’s a spectrum
  
  • Failure of acetabular development - US detectable, no instability. OA at 30-40
  • Femoral head instability - clinical features. OA at 10-20
  • Femoral head displacement - clinical features. OA early and pain

Question 2

What are some risk factors for developmental dysplasia of the hip?

Answer 2

• First born (less compressible uterus - squeezing), female, breech, oligohydramnios, macrosomy, associated disorders (torticollis, calcaneovalgus, clubfoot), FHx of FDR with dysplasia or early THR

Question 3

When does screening for developmental dysplasia of the hip occur?

Answer 3

• 1, 2, 4, 8 weeks, 4, 8, 12 months (clinical exam)
• US at around 6 weeks

Question 4

Describe the clinical features you would look for and the tests you could use to detect developmental dysplasia of the hip. What are the initial investigations?

Answer 4

• Look - skin creases, thigh length (Galeazzi sign), abduction range decreased
• Feel
  
  • Barlow test - push back with adducted hip at 90 degrees flexion
  • Ortolani test - relocate dislocated hip with anterior force while abducting at 90 degrees flexion
• Investigations - US (or Xray if detected after 5 months)

Question 5

When would you trial a brace (Pavlik) harness in a child with developmental dysplasia of the hip? What’s the alternative?

Answer 5

• < 8 months, only for 4-5 weeks
• Surgery (paediatric orthopaedics)

Question 6

How can you develop a rotational profile for a child?

Answer 6

• Gait angle (of feet with direction of gait)
• Forefoot alignment (with hindfoot)
• Thigh-foot angle (with child lying on front)
• Hip rotation (degree of, with child lying on front)

Question 7

What is genu bow? Is it normal? What are the red flags?

Answer 7

• Genu bow = genu valgum
• Physiological to an extent
• Red flags - asymmetry, > 3 y/o, short stature
  
  • Can be caused by rickets, internal tibial torsion

Question 8

What is genu valgum? Is it normal? What are the red flags?

Answer 8

• Opposite of bow leg
• Normal to an extent up to 8 y/o
• Red flags - unilateral, > 10 years, intermalleolar distance > 10cm

Question 9

What can cause a child to have an in-toeing gait?

Answer 9

• Internal tibial torsion
  
  • Generally improves until age 6, otherwise may require surgery
• Inset hips - require correction