What is the diagnosis and management of pediatric hip dysplasia?

Diagnosis and Management of Pediatric Hip Dysplasia

Diagnosis

All newborns and infants should undergo hip examination at every well-child visit using the Ortolani and Barlow maneuvers, with imaging reserved for those with positive findings or risk factors, performed at 4-6 weeks of age using ultrasound. 1, 2

Clinical Examination by Age

Birth to 3 months:

• Perform Ortolani test: abduct and gently lift the flexed thigh while pushing the greater trochanter anteriorly—a palpable "clunk" indicates a dislocated hip reducing into the acetabulum 2
• Perform Barlow test: gently adduct the thigh to dislocate the femoral head posteriorly, then lift and abduct to relocate—this identifies unstable hips that can be dislocated 2
• These maneuvers are most reliable during the first 2-3 months as capsular laxity decreases with age 2
• Distinguish true positive tests from benign "clicking" hips that have no laxity 2

After 3 months:

• Limited hip abduction becomes the most important screening method, though its reliability remains debated with positive predictive values of 40-55% 1
• Assess for asymmetric thigh folds and limb length discrepancy 1, 3
• In walking children, observe for limping, toe-walking on the affected side, increased lumbar lordosis, prominent buttocks, and waddling gait if bilateral 1, 3

Risk Factors Requiring Screening

• Female sex (4-8 times more common) 1, 4
• Family history of DDH 1, 4
• Breech presentation (3 times more common in left hip) 1, 4
• Firstborn status 1, 4
• Large infant size 1, 4
• Oligohydramnios 1, 4

Imaging Protocols

For infants <4-6 months with equivocal exam or risk factors:

• Ultrasound is the preferred modality, performed at 4-6 weeks of age 1
• Do not perform ultrasound during the newborn period (before 2-4 weeks) as high sensitivity leads to overdiagnosis—60-80% of physical exam abnormalities and >90% of ultrasound abnormalities resolve spontaneously 1, 4
• Graf classification: Type IIa (alpha angle 50-59°) typically normalizes with observation alone; Types IIb-IV require treatment 1
• Combined static and dynamic techniques per ACR-AIUM-SPR-SRU practice parameters are standard 1

For infants ≥4-6 months:

• Anteroposterior pelvic radiography becomes the preferred modality as the femoral head ossific nucleus appears (typically 1.5-8 months, often delayed in dysplastic hips) 1
• Measure acetabular index (normal is 30° at birth, decreases with growth; increased in dysplasia) 1
• Assess femoral head position relative to Hilgenreiner and Perkin lines and Shenton arc 1
• Radiographs at 4 months can reliably exclude DDH and decrease unnecessary treatment by 40% in infants with positive ultrasound 1

Critical caveat: Ultrasound performed before 4 weeks has high false-positive rates due to physiologic immaturity and laxity, potentially leading to overtreatment 1, 4. The AAP recommends screening at 4-6 weeks to balance early detection with avoiding false positives 1.

Management

The treatment goal is to obtain and maintain concentric reduction of the femoral head in the acetabulum, with Pavlik harness being first-line treatment for infants with confirmed DDH, initiated after 2 weeks of age. 5, 6

Conservative Management

Observation alone:

• Graf Type IIa hips with stable examination can be observed without bracing, as most normalize spontaneously 1, 4
• Do not initiate treatment in neonates with unstable hips—many stabilize without intervention by 2 weeks 5

Pavlik harness treatment:

• Initiate after 2 weeks of age for persistent hip instability or significant dysplasia 5
• Most effective when applied before 6 weeks of age; can be used up to 6 months 1
• Overall success rate: 67-83% (some sources report 70-95%) 1, 7
• Continue until hips stabilize and show concentric reduction on imaging 5

Risk factors for Pavlik harness failure:

• Initiation after 7 weeks of age 7
• Male sex 7
• Right hip dislocation 7
• Graf Type IV hips 7
• Femoral nerve palsy 7
• Static bracing 7
• Irreducible hips 7
• Low post-reduction alpha angle and <20% femoral head coverage 1

Monitoring During Treatment

Ultrasound surveillance:

• Confirm concentric hip reduction 1
• Assess treatment response 1
• Identify signs of therapy failure 1
• Perform without applied stress, with child in or out of brace per provider discretion 1

Radiography:

• Not preferred during harness treatment due to delayed ossific nucleus appearance and suboptimal positioning 1
• Obtain at or near conclusion of treatment to document bony acetabular development and provide baseline for future surveillance 1

Surgical Intervention

Indications:

• Severe dysplasia or dislocation 1
• Late presentation or diagnosis 1
• Failed nonoperative management 1

Closed reduction:

• Successful in 91% of cases in infants up to one year of age 4
• May be trialed after failed harness treatment 7
• Evidence does not support delaying reduction until ossific nucleus is present 7

Open reduction:

• Required if hip remains irreducible, nonconcentric, or unstable following closed reduction 7

Pre-operative evaluation:

• Obtain complete blood count, platelet count, platelet function study, and von Willebrand screen before any surgical intervention 4
• Screen for easy bruising or bleeding history 4

Referral Timing

• Prompt orthopedic evaluation within 2-4 weeks for confirmed DDH to prevent further acetabular underdevelopment 4
• AAOS recommends pediatric orthopedic referral before 4 weeks of age for equivocal exams or risk factors 1
• A DDH specialist should be involved whenever treatment is initiated 5

Long-term Implications

Untreated DDH leads to:

• Early degenerative joint disease 1, 2
• Impaired function and lifelong disability 1, 2
• Chronic hip pain 8
• Limb length discrepancy 8
• Altered gait and joint contractures 8

Treatment complications:

• Avascular necrosis is the most serious complication and predictor of poor prognosis 2
• Treatment outcomes worsen significantly with increasing delay in presentation 8

Common pitfall: Late presentation is a major negative prognostic factor requiring more complex surgical intervention 3. Continue hip examination at all routine well-child visits through the first year of life, as late-presenting DDH may occur even after normal newborn examination 5.