DDH - General - OrthoNet AI

Modern Study Review (AI-Generated)

High-Yield Summary

Developmental Dysplasia of the Hip (DDH) is a spectrum of hip joint abnormalities ranging from mild acetabular dysplasia to frank dislocation, primarily affecting infants and young children. Early diagnosis and treatment are critical to prevent long-term morbidity such as gait abnormalities, pain, and early osteoarthritis. DDH incidence is approximately 1 in 1000 live births, with a strong female predominance and multiple known risk factors including breech presentation and family history. Modern management emphasizes early clinical and ultrasound screening, with treatment tailored to the severity and age at diagnosis.

Key Diagnostic Findings

Anatomy

Hip joint stability depends on the congruence of the femoral head and acetabulum, supported by the capsule, labrum, ligamentum teres, and surrounding musculature.
Pathologic changes in DDH include a loose capsule, inverted or infolded labrum, hypertrophied pulvinar and ligamentum teres, and tight iliopsoas tendon contributing to mechanical obstruction.

Clinical Presentation

Risk factors: female sex (6-7x higher risk), breech presentation, positive family history (10% in sisters, 1% in brothers), ligamentous laxity.
Associated conditions: congenital muscular torticollis, metatarsus adductus.
Physical exam: Perform Ortolani and Barlow maneuvers, assess leg length discrepancy, asymmetrical thigh or gluteal folds, and evaluate neck, spine, knees, feet, and upper extremities for associated anomalies.

Imaging

Ultrasound: Gold standard for infants <6 months; dynamic and static assessment of hip stability and morphology.
X-rays: Used after 4-6 months when ossification centers appear; assess acetabular index, femoral head position, and Shenton’s line integrity.

Classification Systems

Classification	Description	Clinical Use
Graf Classification (Ultrasound)	Types I-IV based on alpha and beta angles assessing acetabular morphology and femoral head coverage	Guides treatment decisions in infants <6 months
Tönnis Classification (Radiograph)	Grades I-IV based on femoral head displacement and acetabular dysplasia	Used in older infants and children
International Hip Dysplasia Institute (IHDI)	Modern radiographic classification focusing on femoral head position relative to Hilgenreiner’s and Perkin’s lines	Increasingly preferred for standardization

Current Gold Standard Treatment

Non-operative

Pavlik Harness: First-line for infants <6 months with reducible hips; maintains hip in flexion and abduction to promote stable reduction and acetabular development.
Closed Reduction and Spica Casting: Indicated if Pavlik harness fails or in older infants (6-18 months) with reducible dislocations.
Observation: For mild dysplasia without instability in infants >6 months, with close radiographic follow-up.

Operative

Open Reduction: Required for irreducible hips or failed closed reduction, typically after 18 months of age.
Pelvic Osteotomies (e.g., Salter, Pemberton, Dega): Performed to improve acetabular coverage in older children or residual dysplasia.
Femoral Osteotomy: May be combined with pelvic osteotomy to correct femoral anteversion or shorten the femur for stable reduction.

Modern Complications & Outcomes

Complications

Complication	Description	Prevention/Management
Avascular Necrosis (AVN)	Most serious complication; caused by compromised blood supply during reduction	Gentle reduction techniques, avoid excessive abduction, monitor closely
Residual Dysplasia	Persistent acetabular insufficiency leading to instability or arthritis	Timely osteotomy, long-term follow-up
Re-dislocation	Failure of stable reduction	Adequate immobilization, surgical revision if needed
Nerve Injury	Rare; sciatic or femoral nerve injury during surgery	Careful surgical technique

Outcomes

Early diagnosis and treatment yield excellent functional outcomes with normal gait and hip function.
Late diagnosis increases risk of AVN, residual dysplasia, and early osteoarthritis.
Long-term follow-up into adolescence is essential to monitor hip development and intervene as needed.

Classic Clinical Notes

DDH – General

Developmental Dysplasia of the Hip – General

Incidence about 1/1000 (0.1%)
Etiologic associative factors:
ligamentous laxity
females about 6-7 times more likely to get it than males (?hormonal effect)
breech presentation (single or frank breech)
hereditary component – 10% chance in sisters, 1% chance in brothers

Anatomic Associations

congenital muscular torticollis – look at the neck!

metatarsus adductus

DO A CAREFUL PHYSICAL EXAMINATION – neck, spine, knees, feet, U/E

Pathoanatomy

loose capsule initially

The eventual pathology that blocks reduction:

hourglass constriction of capsule which is adherent to pelvic wall

inverted/infolded labrum

hypertrophied pulvinar

hypertrophied ligamentum teres

transverse acetabular ligament

tight iliopsoas (worsens the hourglass constriction of the capsule)

Last Updated on January 25, 2026 by orthonet