A 4-month-old male infant from rural India is brought to the clinic with a history of asymmetric skin folds and limited hip abduction on the right side. On examination, Barlow and Ortolani tests are negative, but Galeazzi sign is positive. Pelvic X-ray shows a dislocated right hip with a shallow acetabulum (acetabular index 35°). What is the most appropriate next step in management?

Explanation

## Clinical Context This is a case of **DDH with fixed dislocation** diagnosed at 4 months of age. The **negative Barlow/Ortolani tests** indicate the hip is **not reducible by dynamic maneuvers** (fixed/irreducible dislocation), while the **positive Galeazzi sign** (asymmetric knee height when hips/knees are flexed) confirms the dislocation. The **pelvic X-ray explicitly confirms a dislocated right hip** with a shallow acetabulum (acetabular index 35°, normal < 25° at this age). ## Why Closed Reduction Under GA + Spica Cast is Correct **Key Point:** At 4 months of age with a **confirmed fixed dislocation on X-ray**, the standard of care per Campbell's Operative Orthopaedics and Tuli's Orthopedics is **closed reduction under general anesthesia followed by spica cast immobilization**. The negative Barlow/Ortolani tests confirm the hip cannot be reduced by bedside maneuvers, necessitating a formal closed reduction in the operating room. **High-Yield:** The management algorithm for DDH by age: - **< 3 months, reducible (Barlow/Ortolani +ve):** Pavlik harness - **3–6 months, fixed dislocation (Barlow/Ortolani −ve, X-ray confirmed):** Closed reduction under GA + spica cast - **6–18 months:** Traction → closed reduction → spica cast (or open reduction if closed fails) - **> 18 months:** Open reduction + pelvic/femoral osteotomy ## Why Other Options Are Incorrect | Option | Reason Incorrect | |--------|-----------------| | **A) Pavlik harness** | Effective only for **reducible** hips (positive Barlow/Ortolani) in infants < 3–4 months. With a fixed dislocation confirmed on X-ray, the harness cannot achieve or maintain reduction and risks avascular necrosis if forced. | | **B) Spica cast after preliminary traction** | Preliminary traction before closed reduction is used in **older infants (6–18 months)** to relax soft tissues prior to reduction. At 4 months with a fixed dislocation, proceeding directly to closed reduction under GA is appropriate and avoids unnecessary delay. | | **D) Open reduction and internal fixation** | Reserved for **failed closed reduction** or children > 18 months. Premature open surgery at 4 months is not indicated as closed reduction has a high success rate at this age. | ## Procedure: Closed Reduction Under GA 1. **General anesthesia** — allows complete muscle relaxation, facilitating reduction 2. **Arthrogram** — confirms concentric reduction and assesses soft tissue interposition 3. **Gentle reduction maneuver** — Ortolani-type reduction under fluoroscopic guidance 4. **Safe zone assessment** — hip positioned in flexion 100–110°, abduction 45–60° (within safe zone to avoid AVN) 5. **Spica cast application** — maintains reduction for 12 weeks 6. **Follow-up X-ray at 6 weeks** — confirms maintained reduction and acetabular remodeling **Clinical Pearl:** The **acetabular index of 35°** (normal < 25° at 4 months) confirms significant dysplasia, but acetabular remodeling is still robust at this age. Successful closed reduction with spica casting allows the femoral head to act as a mold, stimulating acetabular development. **Tip:** The key differentiator in this question is the **X-ray-confirmed dislocation with negative Barlow/Ortolani** = fixed dislocation at 4 months → closed reduction under GA is the next step, not Pavlik harness (which requires a reducible hip) and not preliminary traction (which is for older infants ≥ 6 months). [cite: Campbell's Operative Orthopaedics 13e Ch 33; Tuli's Orthopedics 6e Ch 4; Staheli's Fundamentals of Pediatric Orthopedics 5e]