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developmental dysplasia of the hip DDH Barlow Ortolani Pavlik harness

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Developmental Dysplasia of the Hip (DDH)

Definition & Spectrum

DDH describes abnormal development or dislocation of the hip secondary to capsular laxity and mechanical factors. It is a spectrum, not a single entity:

Grade	Description
Dysplasia	Shallow acetabulum with normal femoral head position
Subluxation	Partial loss of contact between femoral head and acetabulum
Dislocation	Complete loss of contact
Teratologic	Dislocated in utero, irreducible at birth; associated with neuromuscular conditions (arthrogryposis, Larsen syndrome)
Late dysplasia	Presents in adolescence/adulthood

Miller's Review of Orthopaedics, 9th ed.

Epidemiology & Risk Factors

Risk factors in order of importance:

Breech positioning (30–50% of DDH cases)
Positive family history / ligamentous laxity (≥20%)
Female sex (~85% of cases)
Firstborn child (less intrauterine space)
Increased maternal estrogens
Left hip most commonly affected (67% of cases)

Also associated with: postnatal swaddling with hips in extension, torticollis (20%), metatarsus adductus (10%). No association with clubfoot.

A 2025 meta-analysis (PMID 39853978) confirmed breech presentation as the single strongest risk factor for DDH before 3 months of age.

Pathophysiology

If untreated:

Muscles around the hip become contracted
The acetabulum becomes progressively dysplastic
The acetabular cavity fills with fibrofatty tissue (pulvinar)

Obstacles to concentric reduction (important surgically — see illustration):

Iliopsoas tendon
Pulvinar
Hypertrophied ligamentum teres
Contracted inferomedial hip capsule
Transverse acetabular ligament
Inverted labrum

Blocks to reduction in DDH — hip joint anatomy

Blocks to reduction in DDH: iliopsoas tendon, pulvinar, transverse acetabular ligament (Miller's Review of Orthopaedics)

Clinical Diagnosis

Neonatal Screening Tests (most useful <3 months)

Test	Technique	Positive Finding
Ortolani	Elevate + abduct the flexed hip	Palpable clunk as dislocated head reduces back into acetabulum
Barlow	Adduct + depress the flexed hip	Palpable clunk as reduced head dislocates

Ortolani-positive = dislocated but reducible
Barlow-positive = reduced but dislocatable

Caution: bilateral dislocations may show symmetric abduction limitation, masking the finding.

Signs in Older Infants (>3 months)

Limited hip abduction (most reliable sign as laxity resolves)
Galeazzi sign: feet held together, knees flexed — apparent femoral shortening on the affected side
Trendelenburg gait (older children)
Asymmetric gluteal folds (less reliable)
Increased lumbar lordosis, pelvic obliquity

Asymmetric thigh creases and Barlow/Ortolani positioning in DDH screening

Imaging

Age	Modality	Notes
< 4–6 months	Ultrasound (dynamic)	Gold standard — bones not yet ossified; uses Graf angle classification
> 4–6 months	Plain X-ray (AP pelvis)	Femoral head ossifies; assess Hilgenreiner's line, Perkin's line, acetabular index, Shenton's line

Graf classification on ultrasound:

Type I: Normal (α angle >60°)
Type IIa: Physiologically immature (<3 months)
Type IIb: Delayed ossification (>3 months)
Type IIc/D: Critical zone — at risk for dislocation
Type III/IV: Dislocated

Selective ultrasound screening is recommended for high-risk infants (breech, family history).

DDH longitudinal ultrasound and X-ray management series

Treatment — Age-Based Algorithm

0–6 Months: Pavlik Harness

First-line treatment
Maintains hips in ~100° flexion and mild abduction (the "human position")
Worn 23 hours/day until exam and ultrasound normalize
Hip must stay within the safe zone of Ramsey (between maximum adduction before redislocation and excessive abduction causing AVN)
"Pavlik disease": if reduction not achieved in 3 weeks, discontinue → risk of erosion above acetabulum making future reduction harder
Contraindications: teratologic dislocation; narrow safe zone (<40°, consider adductor tenotomy)
Complications: femoral nerve palsy (excessive flexion), avascular necrosis (excessive abduction)

Pavlik harness vs Lorenz position for DDH conservative treatment

6–18 Months: Closed Reduction + Spica Cast

Hip arthrography + percutaneous adductor tenotomy + closed reduction + spica cast
Post-reduction CT or MRI confirms concentric reduction
If closed reduction fails → open reduction

18 Months–3 Years: Open Reduction

Open reduction with femoral shortening osteotomy ± acetabular osteotomy (capsulorrhaphy)

3–8 Years: Acetabular Osteotomy

Salter, Dega, Pemberton, or Staheli procedure

>8 Years: Osteotomy (growth-plate status dependent)

Growth plate open: triple (Steele), double pelvic (Southerland), or Staheli
Growth plate closed: Ganz or Chiari procedures

Adults: Total Hip Arthroplasty (THA)

Complications

Avascular necrosis (AVN) / osteonecrosis of the femoral head — most dreaded complication of both disease and treatment
Degenerative joint disease if untreated
Re-dislocation
Femoral nerve palsy (Pavlik harness)
Persistent acetabular dysplasia requiring further surgery

Key Points Summary

Feature	Detail
Commonest form	Left hip, female, firstborn, breech
Neonatal test	Ortolani (reduce) / Barlow (dislocate)
Best imaging <6 mo	Ultrasound (Graf classification)
Best imaging >6 mo	AP pelvis X-ray
Treatment <6 mo	Pavlik harness
Worst complication	AVN of femoral head
Untreated adult sequela	Severe OA requiring THA

Sources: Schwartz's Principles of Surgery, 11th ed.; Miller's Review of Orthopaedics, 9th ed.; recent evidence from PMID 39853978 (meta-analysis, JAMA Network Open 2025).

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