Developmental Dysplasia of the Hip

Aka: Developmental Dysplasia of the Hip, Congenital Hip Dislocation, Hip Dislocation in the Newborn, Congenital Hip Dysplasia

advertisement

II. Definitions

  1. Developmental Dysplasia of the Hip (DDH)
    1. Acetabulum or femoral head dysgenesis resulting in hip incongruity in infants
    2. Spectrum from hip laxity and instability to hip subluxation and dislocations

III. Epidemiology

  1. Incidence
    1. Hip instability on exam at birth: 0.1 to 0.3% up to 1-2% worldwide
  2. Gender
    1. Girls are 4 times more often affected than boys
    2. May be associated with Progesterone induced greater ligament laxity
  3. Unilateral in 80% of cases (bilateral in 20%)
    1. Left hip in 60% of cases
    2. Intrauterine left occipitoanterior position abuts left hip against maternal spine

IV. Risk Factors

  1. Breech Presentation (Odds Ratio 6)
    1. Unstable hips found in >10% of Breech infants
  2. Female gender (Odds Ratio 4.3)
  3. First born (Odds Ratio 2.7)
  4. Family History (positive in up to one third of cases)
    1. One affected sibling: 6% risk
    2. One affected parent: 12% risk
    3. One affected sibling and one affected parent: 36%
  5. Oligohydramnios
  6. Large for Gestational Age infant
  7. Restrictive Swaddling (see prevention below)
  8. Race
    1. Native American
    2. Hispanic American

V. Pathophysiology

  1. Femoral head dislocates from acetabulum
  2. Results from Acetabular Dysplasia (shallow acetabulum)
    1. Results in subluxed, dislocated or unstable hip
  3. Left hip is affected in 60% of cases
    1. Remainder are right (20%) and bilateral (20%)

VI. Types

  1. Classic Congenital Hip Dislocation
  2. Congenital Abduction Contracture of the Hip
  3. Teratologic Congenital Hip Dislocation
    1. Severe, prenatal fixed dislocation
    2. Associated with genetic and neuromuscular disorders

VII. Associated Conditions

  1. Congenital Torticollis
  2. Breech Presentation in utero
  3. First degree relative with hip dysplasia history
  4. Clubfoot
  5. Metatarsus Adductus
  6. Torticollis

VIII. Symptoms

  1. Painless limp in toddler (best if diagnosed earlier)

IX. Signs: General

  1. Dislocation and Relocation maneuvers
    1. Useful only in first few weeks to months of life
      1. Accuracy decreases as ligamentous laxity resolves
    2. Repeat exam in 2 weeks if equivocal results
    3. Tests
      1. Ortolani Test (relocate hip into acetabulum)
      2. Barlow's Test (attempt to sublux unstable hip)
  2. Pelvis symmetry
    1. Galeazzi's Sign (compare the 2 femur lengths)
    2. Observe for asymmetric skin folds (thigh or gluteal folds)
  3. Hip Range of Motion
    1. Abduction tested with hips flexed to 90 degrees
    2. Abnormal if abduction <60 degrees or less than opposite side by at least 20 degrees difference

X. Signs: Specific Testing

  1. Hip click
    1. Palpable or audible, high-pitched click on Ortolani or Barlow Maneuver
    2. Hip clicks are caused by soft tissue movement and are not related to hip instability or dislocation
    3. Distinguish the benign hip click from the pathologic Hip Clunk (dislocation)
      1. Hip clicks are benign and require no further evaluation
      2. Hip Clunks are managed as Developmental Dysplasia of the Hip (see below)
  2. Hip Clunk (birth to 3 months of age)
    1. Distinct, palpable/audible shift of the femoral head as it is relocated (Ortolani) or dislocated (Barlow)
    2. Hip Clunk suggests Developmental Dysplasia of the Hip, with dislocation or subluxation
  3. Hip instability or laxity
    1. May feel as a tennis ball might move within a cereal bowl without frankly dislocating (no Hip Clunk)
    2. Represents a loose fit of the femoral head with the acetabulum (without subluxation or dislocation)
    3. Relatively mild findings on the spectrum of Developmental Dysplasia of the Hip
  4. Limited hip abduction (age >=2 months)
    1. Abnormal findings require additional evaluation for Developmental Dysplasia of the Hip
    2. Reduced hip abduction
      1. Test with child supine on a flat level surface
      2. Child's hips and knees are flexed to 90 degrees for the test
      3. Abnormal if hip abducts <60 degrees (or >20 degrees difference between sides)
  5. Galeazzi's Sign (age >2 months)
    1. Child lies supine on a flat surface
    2. Feet together with knees and hips flexed to 90 degrees
    3. Abnormal if unequal knee heights
  6. Hip subluxation
    1. Femoral head approaches the edge of the acetabulum but does not fully dislocate
    2. A soft clunk may be palpable on Ortolani or Barlow Maneuvers
  7. Hip Dislocation
    1. Femoral head completely escapes the acetabulum
    2. Most severe on the spectrum of Developmental Dysplasia of the Hip
  8. Trendelenburg Sign
    1. Asymmetric gait with limp on the affected side

XI. Imaging

  1. Avoid imaging for age <4 weeks
    1. Many hip laxity findings resolve spontaneously after 1 month of age
    2. Imaging (esp. XRay) is frequently non-diagnostic in first month of life
  2. Dynamic Hip Ultrasound (infant aged 1-4 months)
    1. Diagnostic for Congenital Hip Dislocation
    2. Evaluates for subluxation and reducibility
    3. High False Positive Rate in age <6 weeks and in age >4 months
      1. However, 90% Negative Predictive Value
    4. Grading based on Graf System (depth of acetabular socket)
      1. Grade I: No abnormality
      2. Grade III: Moderate to severe DDH
      3. Grade IV: Frank dislocation
  3. Hip XRay (ages >=4 months)
    1. Not diagnostic for dislocation until age >4 months
      1. Femoral head not calcified under age 4-6 months
      2. Diagnostic for Acetabular Dysplasia
        1. Abnormal acetabular fossa will be seen
    2. Evaluated with reference lines drawn over AP XRay
      1. Hilgenreiner's Line
        1. Horizontal line through triradiate cartilages
      2. Perkin's Line
        1. Vertical line along each lateral acetabulum
      3. Shenton's Line
        1. Femoral neck medial border
        2. Superior border of obturator foramen

XII. Evaluation: Increased Developmental Dysplasia of the Hip Risk

  1. Indications
    1. Breech Presentation in the third trimester OR
    2. First-degree relative Family History OR
    3. Two or more DDH risk factors
  2. Approach
    1. Equivocal or positive exam results
      1. Refer to orthopedics
      2. Hip Ultrasound at age 4-6 weeks
    2. Normal exam
      1. Hip Ultrasound at age 4-6 weeks
      2. Repeat exam in 2 weeks and well child exam
      3. Refer to orthopedics for findings suggestive of DDH

XIII. Evaluation: Standard Developmental Dysplasia of the Hip Risk

  1. Approach to significant findings (hip subluxation, Hip Dislocation or age over 6 months with findings)
    1. Referral to orthopedics
  2. Approach to mild instability or equivocal exam findings
    1. Repeat exam in 2 weeks
    2. Hip subluxation or dislocation
      1. Refer to orthopedics
    3. Persistent mild hip instability
      1. Obtain Hip Ultrasound or repeat exam every 2 weeks

XIV. Management

  1. Management indicated for hip instability beyond 5 days of life
    1. Goal: Maintain the femoral head in the acetabulum
  2. Step 0: Observation
    1. Indicated only in mild instability for age <6 weeks
    2. Repeat examinations every 2 weeks for first 6 weeks of life
    3. Persistent instability or other DDH findings prompt orthopedic referral for Pavlik Harness
  3. Step 1: Pavlik Harness
    1. Indicated as first-line if age <6 months for frankly dislocated or dislocatable hips
    2. Splints hips in flexed and abducted position (centers femoral head in the acetabulum)
    3. Protocol
      1. Start with harness trial, worn 23 hours per day (off for bathing and diaper changes)
      2. Continue for an initial >=6 to 8 weeks
      3. Examine every 2 to 4 weeks
    4. Efficacy
      1. Long-term effectiveness: 95% (80-90% if frank dislocation)
    5. Complications
      1. Avascular necrosis risk: 0-14% overall (<2% for infants with early Splinting)
      2. Skin irritation
      3. Femoral nerve palsy
    6. Ultrasound should demonstrate reduction at 3 weeks
      1. Reduced: Continue harness for >6 weeks
      2. Not Reduced: Go to Step 2
  4. Step 2: Rigid Abduction Orthosis
    1. Indicated for refractory course with Pavlik Harness
    2. Maintain rigid abduction Orthosis (e.g. Illfeld Orthosis) for 6-8 weeks
  5. Step 3: Closed Reduction and Casting by Orthopedics
    1. Indications
      1. Children over age 6 months AND
      2. No reduction with Pavlik Harness or rigid Orthosis
    2. Attempted closed reduction under arthrogram
    3. Hip Spica Casting for 6 weeks
    4. Positioning confirmed by post-op MRI or CT
    5. Avascular necrosis risk similar to Pavlik Harness (0-14% overall, <2% for infants with early Splinting)
  6. Step 4: Surgical Open reduction
    1. Indicated
      1. Age >18 months OR
      2. Refractory cases to closed reduction and Casting
    2. Requires multi-step procedure
      1. Tendon lengthening
      2. Clearing tissues obstructing relocation
      3. Tightening hip capsule
      4. Acetabular Osteotomy if performed after age 18 month
    3. Complications
      1. Re-disclocation
      2. Avascular necrosis (5-60% risk)

XV. Course

  1. Many unstable hips at birth stabilize by 5 days of life

XVI. Prognosis

  1. Best outcomes are with diagnosis and treatment started before age 6 months
    1. Delayed treatment risks worse outcomes (early onset Hip Osteoarthritis)
  2. Monitor children with imaging until skeleton mature

XVII. Complications

  1. Hip Osteonecrosis
  2. Premature Osteoarthritis of the hip as early as late teen

XVIII. Prevention

  1. Screening guidelines vary by organization (AAP, AAFP, USPTF)
    1. USPTF and AAFP found insufficient evidence for universal screening
  2. American Academy of Pediatrics (AAP) recommendations
    1. Screen all newborns with Ortolani Maneuver and Barlow Maneuver
    2. Repeat Hip Exam at well child, routine visits up until 6 to 9 months
    3. High risk patients (e.g. Breech, Family History) should be screened with Hip Ultrasound
  3. Avoid restrictive infant swaddling
    1. Restrictive swaddling fixes the hips in extended and adducted position for prolonged periods
    2. Hip safe swaddling, in contrast, allows the hips to move freely into flexed and abducted positions

XIX. References

  1. (2006) Pediatrics 117:898-902 [PubMed]
  2. Harding (1997) J Pediatr Orthop 17:1149-52 [PubMed]
  3. Jackson (2014) Am Fam Physician 90(12): 843-50 [PubMed]
  4. Kim (2025) Am Fam Physician 112(5): 546-52 [PubMed]
  5. Storer (2006) Am Fam Physician 74(8):1310-6 [PubMed]
  6. Vitale (2001) J Am Acad Orthop Surg 9:401-11 [PubMed]

Images: Related links to external sites (from Bing)

These images are a random sampling from a Bing search on the term "Developmental Dysplasia of the Hip." Click on the image (or right click) to open the source website in a new browser window. Search Bing for all related images

Related Topics in Pediatrics

advertisement