Developmental dysplasia of the hip (DDH)

Developmental dysplasia of the hip (DDH) is gradually replacing the old term 'congenital dislocation of the hip' (CDH). It affects around 1-3% of newborns.

Risk factors

• female sex: 6 times greater risk
• breech presentation
• positive family history
• firstborn children
• oligohydramnios
• birth weight > 5 kg
• congenital calcaneovalgus foot deformity

DDH is slightly more common in the left hip. Around 20% of cases are bilateral.

Screening for DDH

• the following infants require a routine ultrasound examination
  • first-degree family history of hip problems in early life
  • breech presentation at or after 36 weeks gestation, irrespective of presentation at birth or mode of delivery
  • multiple pregnancy
• all infants are screened at both the newborn check and also the six-week baby check using the Barlow and Ortolani tests

Clinical examination

• Barlow test: attempts to dislocate an articulated femoral head
• Ortolani test: attempts to relocate a dislocated femoral head
• other important factors include:
  • symmetry of leg length
  • level of knees when hips and knees are bilaterally flexed
  • restricted abduction of the hip in flexion

Imaging

• ultrasound is generally used to confirm the diagnosis if clinically suspected