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Combined Paed

DDH - conservative treatment and complications

Pavlik harness for infant dysplasia and the complications that follow treatment.

17 questions 2 source pages

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17 questions
Q1What is a Pavlik harness and when is it used?▸
  • Dynamic corrective orthosis maintaining flexion and preventing adduction to keep the hip reduced for dynamic remodelling
  • Use up to 6 months old
  • 90% success in < 3 month old presentation
  • Other abduction brace: von Rosen splint
Q2What are the indications for a Pavlik harness?▸
  • Ortolani positive
  • Barlow positive at 6 weeks
  • Fracture femur
Q3Describe the parts and application of the Pavlik harness.▸
  • Chest strap at nipple line (can place hand in between)
  • Shoulder straps at anterior axillary line
  • Stirrup at popliteal fossa (not too distal or else knee hyperflexion)
  • AM strap maintains 100 degrees flexion, along anterior axillary line
  • PL strap prevents adduction; knees able to come together but not touch
Q4What advice is given to parents on the Pavlik harness?▸
  • Tighten till markers; keep two sets, one for washing
  • Assess kicking of leg and upper limb movement (brachial plexus)
  • Change napkin in the harness; sponge bath and dry completely
  • No self adjustment; regular P&O and ortho follow-up
Q5What is the timing of follow-up and ultrasound in Pavlik harness treatment?▸
  • Continue until hip stable clinically and radiologically (~6 weeks) + 6 weeks
  • USG: within 2 weeks of starting, at the end of the 1st 6 weeks, and before stopping the harness
Q6What are the complications of Pavlik harness treatment?▸
  • Failure of reduction: inferior dislocation (too much flexion), Pavlik harness disease (splintage in incongruent reduction > 1mth)
  • AVN (too much abduction) ~2.4%
  • Femoral nerve palsy (too much flexion) ~2.5%; if persisting beyond 3 days, probability of success only 30%
  • Murnaghan JBJS 2011: adjust or temporarily suspend, do not completely abandon the harness
Q7What is the aim of treatment with a Pavlik harness?▸
  • Maintain a stable concentric reduction
  • Promote normal growth of the femoral head and acetabulum
Q8What is the application sequence of the Pavlik harness?▸
  • Supine; fasten the chest strap first
  • Fasten the shoulder straps to keep the chest strap at the nipple line
  • Feet into the stirrups one by one
  • Fasten AM strap to flex the hip
  • PL strap last
Q9What is assessed at follow-up during Pavlik harness treatment?▸
  • Confirm concentric reduction clinically and radiologically
  • Adjust size and tension (mainly chest strap and PL strap)
  • Compliance
  • Complications: loss of reduction, nerve palsy
Q10What are the risk factors for Pavlik harness failure?▸
  • Graf type IV or radiographically dislocated hips
  • Treatment after 3 months of age; non-visible ossific nucleus at start
  • Prolonged duration of treatment; significant adductor contracture
  • Bilateral disease, low alpha angle, femoral head coverage < 20%
  • Initial irreducibility, advanced age, poor parental compliance
  • Larger patients are also at risk
Q11What is the Pavlik harness success rate and the supporting study?▸
  • 85-95% (Omeroglu, Turkey, CORR 2016)
  • 90% success in presentation < 3 months old
Q12What is Pavlik harness disease?▸
  • Hip not reduced in the harness causing superior acetabular erosion
  • Occurs with splintage in incongruent reduction > 1mth
Q13What are the human and frog positions in an abduction brace?▸
  • Human position: 95 deg flexion, 45 deg abduction
  • Frog position: extreme flexion and abduction
Q14What are Salter's criteria for AVN in DDH?▸
  • Any one of the following:
  • Failure of formation or growth of ossific nucleus 1 year after reduction
  • Broad metaphysis
  • Increased density and fragmentation of the head
  • Residual deformity after ossification
Q15What is the Kalamchi and McEwen classification of AVN?▸
  • 1: mild with delayed ossification
  • 2: lateral, valgus deformity
  • 3: central, shortening
  • 4: complete, varus deformity
Q16What is the risk of AVN by treatment?▸
  • Pavlik harness: 1-5%
  • Closed reduction + hip spica: 10%
  • Open reduction: up to 30%
Q17What is the differential diagnosis of AVN in DDH?▸
  • MED
  • Perthes
  • Infection
  • DDH with AVN
  • PFFD
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