Developmental Dysplasia of Hip

DDH Fundamentals - Hip Hitch 101

• Definition: DDH is a spectrum of developmental abnormalities affecting the immature hip joint, ranging from subtle acetabular dysplasia to frank dislocation of the femoral head.
• Incidence: 1-3 cases per 1000 live births.
• Key Risk Factors:
  • 📌 Female sex (4-6x higher risk)
  • 📌 Firstborn child
  • 📌 Family history of DDH
  • 📌 Frank breech presentation
  • 📌 Fluid (Oligohydramnios)
  • Left hip predominance
  • Improper swaddling (legs extended, adducted)

⭐ Breech presentation is a highly significant risk factor for DDH.

Pathoanatomy & Diagnosis - Spotting Wobbly Joints

Pathoanatomy:

• Acetabular Dysplasia: Shallow, oblique socket (↑ Acetabular Index).
• Femoral Head: Subluxated/dislocated, often superolateral.
• Capsule & Ligaments: Stretched, lax; ligamentum teres hypertrophy.
• Soft Tissue Obstacles: Inverted limbus, pulvinar, tight adductors/iliopsoas.

Clinical Diagnosis:

• Neonates/Infants (<3 months):
  • Barlow Maneuver: Dislocates (Adduct + Posterior pressure). 📌 "Barlow = Bad / Back"
  • Ortolani Maneuver: Reduces (Abduct + Anterior pressure). 📌 "Ortolani = Out / Open"
• Infants (3-12 months):
  • Limited hip abduction (< 60°).
  • Galeazzi Sign: Unequal knee heights (femoral shortening).
  • Asymmetric thigh/gluteal skin folds.
• Walking Child (>12 months):
  • Painless limp / Trendelenburg gait.
  • Waddling gait (if bilateral DDH).

⭐ Ortolani and Barlow tests are most reliable in the first 2-3 months; sensitivity decreases later due to soft tissue contractures.

Imaging:

Management Strategy - Align & Conquer

Goal: Achieve stable, concentric hip reduction. Treatment guided by age at diagnosis.

• Key Principles:
  • Early intervention yields best outcomes.
  • Avoid forceful abduction (↑ AVN risk).
  • Regular follow-up for growth & AVN monitoring.

• Pavlik Harness (0-6 months):
  • Dynamic flexion (100-110°) & abduction (30-50°) orthosis.
  • Worn 23 hrs/day. Wean after USG normalisation.
  • Monitor weekly initially.
  • ⚠️ Complications: Femoral nerve palsy, AVN, skin issues.

⭐ Pavlik harness "safe zone" (Ramsey): Hip flexion 90-110°, abduction 30-60°. Crucial to prevent AVN & ensure reduction.

• Closed Reduction (CR) + Spica Cast (6-18 months):

  • Under GA; adductor tenotomy common.
  • Confirm reduction: arthrogram, CT ("CT stabogram").
  • Cast duration: ~3 months.

• Open Reduction (OR):

  • If CR fails or older children (>18 months).
  • Often requires femoral and/or pelvic osteotomies for stability.
    • Pelvic: Salter, Dega, Pemberton.
    • Femoral: Shortening, Varus Derotation Osteotomy (VDRO).

Complications & Long-Term - Pitfalls & Prognosis

• Avascular Necrosis (AVN): Most serious. Risk: forceful reduction, extreme abduction.
• Residual Dysplasia: Leads to early Osteoarthritis (OA), chronic pain.
• Redislocation/Subluxation
• Joint Stiffness: Especially limited abduction.
• Gait Abnormalities: Persistent limp, waddling.
• Leg Length Discrepancy
• Premature Physeal Arrest
• Prognosis: Good if treated <6 months. Delayed diagnosis ↑ long-term OA risk.

  ⭐ Avascular necrosis (AVN) of the femoral head is the most common serious complication following reduction maneuvers for DDH.

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High‑Yield Points - ⚡ Biggest Takeaways

• Neonatal screening: Barlow (dislocates), Ortolani (relocates); Galeazzi sign in older infants.
• Risk factors: Female, Firstborn, Family Hx, Frank breech (4Fs).
• Diagnosis: Ultrasound < 6 months; X-ray > 6 months (Shenton's line, ↑ Acetabular Index).
• Treatment < 6 months: Pavlik harness (flexion, abduction).
• Treatment 6-18 months: Closed reduction & spica cast; Open reduction if older/failed.
• Complication: Avascular necrosis (AVN) of femoral head.
• Untreated: Leads to limp, pain, early osteoarthritis.