Diagnosing and Managing Developmental Dysplasia of the Hip

High-Yield Executive Summary

• Early diagnosis of Developmental Dysplasia of the Hip (DDH) is critical; ultrasound screening before 6 months of age is the gold standard for infants at risk.
• The Graf classification system guides non-operative management, while the presence of irreducible dislocation or failed closed reduction mandates surgical intervention.
• Closed reduction with spica casting remains first-line for infants under 18 months; open reduction and pelvic osteotomy are reserved for older children or failed closed reductions.
• Surgical approach selection (anterior vs. medial) depends on patient age and hip anatomy; acetabular remodeling potential decreases after 18 months, influencing osteotomy timing.
• Intraoperative fluoroscopy and arthrography optimize reduction quality and minimize iatrogenic injury; vigilance for avascular necrosis (AVN) risk factors is essential.

Clinical Fundamentals

Relevant Anatomy and Biomechanics

The hip joint is a ball-and-socket synovial joint formed by the femoral head and the acetabulum of the pelvis. The acetabulum is a concave structure composed of the ilium, ischium, and pubis, covered by a fibrocartilaginous labrum that deepens the socket. Stability depends on congruent articulation, capsuloligamentous support (iliofemoral, pubofemoral, and ischiofemoral ligaments), and dynamic muscular control.

In DDH, abnormal acetabular development and capsular laxity lead to subluxation or dislocation of the femoral head. The biomechanics of the hip are altered, resulting in abnormal load distribution, which impairs acetabular ossification and femoral head development. Early reduction restores normal joint mechanics, promoting acetabular remodeling.

Epidemiology

DDH incidence varies globally, approximately 1-2 per 1000 live births for dislocation, with higher rates of subluxation and dysplasia. Female infants are affected 4-5 times more frequently, likely due to ligamentous laxity influenced by maternal hormones. Breech presentation, family history, and first-born status increase risk. Left hip involvement is more common, and bilateral cases occur in 20-30%.

Classification & Diagnosis

Classification Systems Guiding Management

Diagnostic Pearls and Pitfalls

• Ultrasound is the preferred modality before 6 months; static and dynamic views assess acetabular morphology and femoral head stability.
• Radiographs become reliable after 4-6 months when ossification centers appear; use anteroposterior pelvis views with the infant in a neutral position.
• Pitfall: Misinterpretation of physiologic hip laxity in neonates can lead to overtreatment; dynamic ultrasound helps differentiate.
• Pitfall: Failure to obtain true AP pelvis radiographs can obscure subluxation or dislocation.
• Clinical pearl: Galeazzi sign and asymmetric thigh/gluteal folds are sensitive physical exam findings but require confirmation with imaging.

The Decision-Making Algorithm

Non-Operative vs. Operative Management Criteria

Surgical Approach and Implant Selection

• Anterior (Smith-Petersen) approach is preferred for open reduction in children >12 months; allows capsulotomy, iliopsoas release, and acetabular procedures.
• Medial (Ludloff) approach is reserved for infants <12 months; less invasive but limited acetabular access.
• Pelvic osteotomies (Salter, Pemberton, Dega) are selected based on acetabular morphology and patient age; rigid fixation with screws or K-wires is standard.
• Femoral osteotomy (varus derotation) is indicated for excessive femoral anteversion or to improve joint stability.

Surgical Mastery & Pearls

Step-by-Step Conceptual Overview of Open Reduction via Anterior Approach

1. Patient positioning: Supine on radiolucent table with fluoroscopy available.
2. Incision and exposure: Curvilinear Smith-Petersen incision; identify and protect lateral femoral cutaneous nerve.
3. Capsulotomy: T-shaped or inverted T capsulotomy to expose the hip joint.
4. Soft tissue releases: Iliopsoas tendon release and transverse ligament excision to facilitate reduction.
5. Removal of obstacles: Excise pulvinar tissue and hypertrophic ligamentum teres.
6. Reduction: Gentle manipulation under fluoroscopy; confirm concentric reduction.
7. Capsular repair: Tighten capsule to maintain reduction.
8. Pelvic osteotomy: Perform if acetabular dysplasia is severe; fixate with screws.
9. Spica casting: Hip positioned in 90-100° flexion and 45° abduction.

Intraoperative Red Flags and Technical Tips

• Red flag: Excessive force during reduction risks femoral head osteonecrosis.
• Tip: Use arthrography intraoperatively to confirm reduction and identify soft tissue interposition.
• Red flag: Overabduction in spica cast increases AVN risk; maintain safe abduction angles.
• Tip: Preserve blood supply by careful dissection around the medial femoral circumflex artery.
• Tip: Avoid excessive femoral shortening osteotomy unless hip cannot be reduced without undue tension.

Evidence-Based Synthesis

Landmark studies have established the efficacy of early ultrasound screening and Pavlik harness treatment in reducing late presentations and surgical interventions. The multicenter studies by the International Hip Dysplasia Institute have validated the IHDI classification as a reliable predictor of surgical outcomes.

Recent randomized controlled trials comparing open reduction alone versus open reduction with pelvic osteotomy demonstrate improved acetabular coverage and reduced re-dislocation rates with combined procedures in children older than 18 months. However, controversy remains regarding the optimal timing of osteotomy and the choice between Salter versus Pemberton techniques, with surgeon experience and patient-specific anatomy guiding decisions.

Meta-analyses highlight that AVN remains the most significant complication, with risk factors including age >18 months at reduction, forceful closed reduction, and excessive abduction. Emerging evidence supports the use of intraoperative arthrography and fluoroscopy to minimize this risk.

Pro-Tip: Surgical Excellence in DDH Management

Mastery in DDH surgery hinges on nuanced patient selection and meticulous technique. Prioritize gentle, atraumatic reduction maneuvers and intraoperative imaging to confirm concentric reduction. Tailor pelvic osteotomy choice to acetabular morphology rather than surgeon preference alone. Vigilantly monitor abduction angles in casting to prevent AVN. Finally, cultivate a multidisciplinary approach involving radiologists and pediatricians to optimize early diagnosis and follow-up, ensuring durable, functional hip joints into adulthood.

Last Updated on January 26, 2026 by OrthoNet AI