2. DDH
• Shallow acetabular fossa &
superolateral migration of femoral
head
• Left hip 60%
• Bilateral hips 20%
• F:M ratio 6:1
• Predisposes to labral tear and
premature OA
• Avascular necrosis
3.
4.
5. DDH
• Upper femoral epiphysis should be in the inner lower quadrant
• Lateral subluxation - capital epiphysis >= 2 mm from teardrop
to metaphysis
• Superior subluxation - delta of >=2 mm from Hilgenreiner's line
to metaphysis compared with normal side
• Disruption of Shenton’s line
• Center edge angle of < 25
• Secondary signs
• Excessive femoral head anteversion
• Delayed ossification of femoral capital epiphysis
12. Crowe Classification
• Based on the extent of proximal migration of the femoral head
• I: less than 50% subluxation
• II: 50 - 75%
• III: 75 - 100%
• IV: greater than 100% subluxation
• Vertical distance from the inter-teardrop line to the inferomedial
head-neck junction divided by:
• Height of femoral head
• 20% of total pelvic height
