Eduovisual
Pediatrics (System-Integrated)
Developmental dysplasia of the hip
— "Developmental" replaces older "congenital" term because some hips dislocate after birth and dysplasia evolves over months.
— Left hip more commonly affected (~60%) due to typical in-utero positioning against maternal lumbosacral spine.
— Clinical instability: ~1 in 100 newborns; frank dislocation ~1 in 1000.
— F:M ratio ~4–8:1 (estrogen + ligamentous laxity).
— Higher in firstborns, breech presentation, oligohydramnios, family history, and swaddling cultures that hold hips extended/adducted.
— Combination of ligamentous laxity, shallow acetabulum, and mechanical forces preventing concentric reduction of femoral head.
— Untreated → progressive acetabular dysplasia, delayed walking, Trendelenburg gait, and early-onset osteoarthritis by 3rd–5th decade.
— Newborn nursery: routine Barlow/Ortolani maneuvers.
— 2-week and 2-month visit: persistent positive maneuvers or asymmetric thigh/gluteal folds.
— 3–6 months: limited hip abduction is the most reliable sign (Ortolani/Barlow lose sensitivity as joint stiffens).
— Walking age: toe-walking, limb-length discrepancy, waddling Trendelenburg gait, or hyperlordosis.
Board pearl: Breech presentation at ≥34 weeks gestation, regardless of mode of delivery or current exam findings, mandates hip ultrasound at 6 weeks of age. Female + breech = highest-risk combination and is essentially always tested.
— Usually asymptomatic; detected only on screening exam.
— Parents may report a "click" with diaper changes — most clicks are benign ligamentous; a true "clunk" of relocation/dislocation is pathologic.
— Asymmetric thigh or gluteal skin folds noted at bath time.
— Decreased range of motion, especially abduction <60° with hip flexed.
— Apparent limb-length discrepancy — affected leg shorter.
— Delayed onset of crawling or pulling to stand on the affected side.
— Delayed walking, painless limp, Trendelenburg gait (pelvis tilts down on the swing-leg side because contralateral abductors are weak/displaced).
— Bilateral DDH → waddling gait, exaggerated lumbar lordosis, wide-based stance.
— Toe-walking on affected side to compensate for shortening.
— Pregnancy: breech presentation, oligohydramnios, multiple gestation.
— Birth: mode of delivery (external cephalic version doesn't eliminate risk), birth weight >4 kg.
— Family history: first-degree relative with DDH, hip replacement <50, or "hip problems as a baby."
— Swaddling practice: tight lower-extremity swaddling with hips extended/adducted increases risk; "hip-healthy" swaddling allows hip flexion/abduction.
— Associated conditions: congenital muscular torticollis (20% co-occur), metatarsus adductus, clubfoot, plagiocephaly.
— Painless limp in a toddler.
— Limb-length discrepancy noted at shoe fitting.
— "Late walker" with otherwise normal development.
Key distinction: A symmetric "click" without instability is usually benign soft-tissue snapping; an audible/palpable clunk with the Ortolani maneuver represents the femoral head relocating into the acetabulum and is diagnostic until proven otherwise. Always document which maneuver elicits the finding.
— Hip flexed 90°, adducted; gentle posterior pressure on the knee.
— Positive = palpable "clunk" as femoral head exits acetabulum posteriorly.
— Most useful in first 8–12 weeks.
— Hip flexed 90°, abducted while lifting the greater trochanter anteriorly with the examiner's fingers.
— Positive = palpable clunk as head re-enters acetabulum.
— Sensitivity declines after 3 months as soft tissues contract.
— Infant supine, hips and knees flexed, feet flat on table.
— Positive = knees at unequal heights → suggests unilateral hip dislocation or femoral shortening.
— Falsely negative in bilateral DDH (both sides shortened equally).
— With hips flexed, normal abduction is ~75°; <60° or asymmetry >10° is concerning.
— Becomes the most reliable sign after 3 months of age.
— Symmetry of thigh/gluteal/labial folds (nonspecific but a clue).
— Abduction angles bilaterally.
— Leg-length symmetry.
— Presence/absence of Ortolani/Barlow.
Step 3 management: Any positive Ortolani/Barlow in a newborn → refer to pediatric orthopedics; do not order an x-ray (femoral head is unossified). In the first 4–6 weeks, even ultrasound is often deferred because physiologic laxity causes false positives; ultrasound is the modality of choice from 4–6 weeks to 4–6 months.
— <4–6 months: Hip ultrasound — femoral head is cartilaginous and not visible on x-ray.
— >4–6 months: AP pelvis radiograph — ossification center of femoral head (appears 4–6 months) is now visible.
— Positive Ortolani or Barlow at any age → orthopedics referral first; imaging per orthopedist.
— Equivocal exam (soft click, mild asymmetry) at 2 weeks → repeat exam at 2 weeks; if persistent, ultrasound at 6 weeks.
— Breech presentation at ≥34 weeks (any sex) → ultrasound at 6 weeks of age.
— Female + family history of DDH → ultrasound at 6 weeks.
— Some experts add: female + breech → ultrasound and AP pelvis at 4 months.
— Alpha angle (bony acetabular roof): normal ≥60°.
▪ Type I (≥60°): normal.
▪ Type IIa (50–59°, <3 mo): physiologic immaturity — repeat at 6 weeks.
▪ Type IIc/D (43–49°): dysplastic.
▪ Type III/IV (<43°): subluxated/dislocated.
— Beta angle (cartilaginous roof): normal <55°.
— Dynamic component assesses stability with stress maneuvers.
— Hilgenreiner line (horizontal through triradiate cartilages) and Perkin line (vertical at lateral acetabulum) divide the hip into 4 quadrants — ossific nucleus should sit in the inferomedial quadrant.
— Acetabular index (angle between Hilgenreiner and acetabular roof): normal <30° at 6 months, <25° at 1 year.
— Shenton line (smooth arc from inferior femoral neck to superior obturator foramen) — broken in dislocation.
Board pearl: Universal ultrasound screening of all newborns is not recommended — it leads to overtreatment of physiologic laxity. Selective screening of risk-positive infants and serial clinical exams are the standard.
— Persistently abnormal exam with normal ultrasound → repeat ultrasound in 4–6 weeks (joint may evolve).
— Borderline radiographic findings → orthopedic measurement of acetabular index, center-edge angle (Wiberg) in older children.
— Used during closed or open reduction to confirm concentric reduction and identify obstacles (inverted limbus, hypertrophied ligamentum teres, transverse acetabular ligament, capsular constriction — the "hourglass" deformity).
— Provides dynamic assessment under anesthesia.
— Post-reduction confirmation of concentric reduction within the spica cast — limited-slice "low-dose CT" protocols minimize radiation.
— Pre-operative planning for complex acetabular reconstructions in older children.
— Radiation-free alternative for post-reduction confirmation, increasingly preferred over CT in young children.
— Excellent for visualizing cartilaginous structures, labrum, and blood supply.
— Detects avascular necrosis (AVN) of the femoral head — a feared complication of treatment.
— Performed when reduction is planned; allows definitive assessment of stability, "safe zone" of abduction (Ramsey safe zone — the arc between redislocation in adduction and AVN risk in extreme abduction).
— Isolated DDH does not require genetic testing.
— If associated with multiple joint contractures, arthrogryposis, Ehlers-Danlos, Larsen syndrome, or skeletal dysplasia features → genetics referral; these "teratologic" hip dislocations are present at birth, often irreducible, and behave differently.
— Age at diagnosis (directly determines treatment).
— Reducibility (Ortolani-positive = reducible; irreducible = older or teratologic).
— Bilateral vs unilateral.
— Associated anomalies.
Key distinction: Typical DDH is usually detectable in the perinatal period and reducible early; teratologic dislocation (with syndromes, neuromuscular disorders) is present in utero, often irreducible by Ortolani, and frequently requires open reduction. Both can coexist with other "packaging" deformities.
— Pavlik harness is first-line.
— Holds hips in flexion (~100°) and abduction, promoting concentric reduction and acetabular remodeling.
— Worn 23 hours/day initially; weaned over weeks to months based on ultrasound progress.
— Success rate ~85–95% if started <6 weeks; declines with age.
— Discontinue if no reduction by 3–4 weeks — risk of Pavlik disease (posterior acetabular wall erosion from persistent posterior dislocation).
— Closed reduction under general anesthesia + spica cast.
— Often preceded by ~2–3 weeks of traction (less commonly used now).
— Intraoperative arthrography confirms reduction.
— Spica cast 3–4 months total with cast changes; followed by abduction brace.
— Open reduction, often with adjunctive femoral shortening osteotomy (to decompress and reduce AVN risk) and/or pelvic osteotomy (Salter, Pemberton, Dega) to deepen acetabulum.
— Spica casting post-op.
— Salvage procedures (Chiari, shelf), periacetabular osteotomy (PAO, Ganz) for symptomatic dysplasia.
— Total hip arthroplasty in young adults with established arthritis — earlier than ideal due to delayed diagnosis.
— Rigid abduction orthoses (e.g., von Rosen, Ilfeld, Rhino) for older infants or as transition from Pavlik.
— Double diapering is not effective treatment.
Step 3 management: A 2-month-old with confirmed dysplastic hip on ultrasound (alpha 45°, Ortolani-positive) → Pavlik harness application by pediatric orthopedist with ultrasound follow-up at 1–2 weeks to confirm reduction. The right answer on a vignette is almost never "observe" once dysplasia is confirmed.
— Anterior straps maintain hip flexion 90–110°.
— Posterior straps limit adduction but do not force abduction — forced abduction increases AVN risk.
— Applied and adjusted by a trained orthopedist or specialty nurse; parents should not readjust straps.
— Worn over a thin shirt to prevent skin breakdown; diaper changed without removing harness.
— Follow-up ultrasound at 1–2 weeks to confirm reduction.
— If reduced: continue full-time wear ~6–12 weeks, then part-time/night wear with periodic imaging until alpha angle and acetabular index normalize.
— If not reduced by 3–4 weeks → abandon Pavlik and proceed to closed reduction.
— Femoral nerve palsy (excessive flexion) → loss of active knee extension; relieve flexion to <90°.
— Brachial plexus injury from shoulder straps.
— AVN of femoral head (1–10%) — minimized by allowing spontaneous abduction.
— Skin breakdown in groin/popliteal fossa.
— Pavlik disease: posterior acetabular wall flattening from prolonged use on an unreduced hip.
— Perioperative cefazolin for open reductions/osteotomies.
— Multimodal analgesia post-spica: acetaminophen, ibuprofen (when age-appropriate), short-course opioids, diazepam for muscle spasm in older children.
— DVT prophylaxis is not routine in young children but considered in postpubertal patients.
— Bathe with sponge baths; never remove harness for bathing without orthopedist guidance.
— Check feet daily for color/movement; report swelling, decreased kicking, knee not actively extending.
— Car seat use: hips remain flexed/abducted — most standard seats accommodate Pavlik; spica casts require special seats.
Board pearl: A 6-week-old in a Pavlik harness develops inability to actively extend the knee → suspect femoral nerve palsy from excessive hip flexion. Next step: reduce hip flexion or temporarily discontinue harness; palsy typically resolves within days.
— Performed under general anesthesia in OR.
— Adductor tenotomy often added to release contracture and widen "safe zone."
— Arthrogram confirms concentric reduction.
— Hip placed in human position: flexion ~100°, abduction ~45–55° (within safe zone).
— Avoid extreme abduction >60° → high AVN risk.
— Spica cast applied, changed at ~6 weeks, total casting 3–4 months, followed by abduction brace until acetabular index normalizes.
— Intraoperative arthrogram + MRI or limited-slice CT through the spica to verify concentric reduction.
— MRI preferred to avoid radiation; assesses femoral head perfusion.
— Anterior (Smith-Petersen) approach most common; medial (Ludloff) approach for younger infants.
— Obstacles addressed: inverted labrum/limbus, pulvinar, hypertrophied ligamentum teres, tight iliopsoas tendon, transverse acetabular ligament, capsular hourglass.
— Varus derotation shortening osteotomy — corrects excessive anteversion/valgus and decompresses the joint to reduce AVN risk in children >2–3 years.
— Salter innominate osteotomy: redirects acetabulum anterolaterally; for ages 1.5–6 years with mild dysplasia and concentric reduction.
— Pemberton / Dega (incomplete): reshape acetabular volume; useful in larger acetabulum.
— Triple/Ganz periacetabular (PAO): adolescents and skeletally mature patients with symptomatic residual dysplasia.
— Salvage (Chiari, shelf): non-concentric hips, older patients.
CCS pearl: For a 14-month-old with persistent dislocation after failed Pavlik, your ordered sequence on CCS: NPO → pediatric anesthesia consult → orthopedic surgery consult → OR for examination under anesthesia, closed vs open reduction with arthrography → post-reduction MRI through spica → orthopedics follow-up in 6 weeks for cast change.
— Present in 3rd–5th decade with early-onset hip osteoarthritis — groin pain, decreased internal rotation, antalgic gait.
— Radiographs: shallow acetabulum, decreased center-edge angle (<20°), femoral head uncoverage, secondary osteoarthritic changes.
— Workup: AP pelvis, false-profile view, MRI for labral tears (very common in dysplastic hips).
— Periacetabular osteotomy (PAO) for symptomatic dysplasia with preserved joint space (Tönnis grade 0–1) in patients <40–45 years.
— Total hip arthroplasty for established arthritis — technically demanding due to small acetabulum, excessive anteversion, leg-length discrepancy, abductor insufficiency; higher revision rates than primary OA THA.
— Adjust perioperative analgesia: avoid NSAIDs in significant renal impairment; weight-based opioid dosing with hepatic adjustment.
— Cefazolin renally cleared — adjust for impaired clearance.
— Counsel about earlier osteoarthritis risk; weight management; low-impact exercise; avoid prolonged high-impact sports.
— Screen and treat osteoporosis aggressively if planning future THA.
— Spastic hip displacement in CP, especially GMFCS levels IV–V, is mechanistically different (muscle imbalance) and screened with serial AP pelvis x-rays.
— Surveillance: annual radiographs; migration percentage >30% triggers intervention (adductor release, varus derotation osteotomy, pelvic reconstruction).
Key distinction: Classic DDH = acetabular dysplasia primary, treated mechanically. CP hip dysplasia = muscle imbalance primary, requires soft-tissue + bony surgery and ongoing surveillance. Step 3 vignettes occasionally test the CP surveillance algorithm — migration percentage is the key number.
— Barlow/Ortolani in the nursery, 2-week, 1-month, 2-month visits.
— Hip abduction and Galeazzi at every visit through 12 months.
— Gait assessment through 24 months.
— ≥34 weeks gestation, any presentation at delivery (i.e., even if successfully turned by ECV or delivered by C-section) → DDH risk persists.
— AAP recommends hip ultrasound at 6 weeks of age regardless of exam findings.
— Some institutions also obtain AP pelvis at 4–6 months.
— First-degree relative with DDH → ultrasound at 6 weeks.
— Female + breech is the highest-risk combination.
— Native American (especially in cradleboard cultures), some Eastern European populations historically show higher rates linked to tight extended-leg swaddling.
— Counsel "hip-healthy swaddling": arms swaddled, but lower extremities free to flex and abduct ("frog leg" position).
— Baby carriers/wraps: choose designs that support thighs to the knee with hips flexed and abducted ("M position"); avoid narrow-base carriers that dangle the legs.
— Defer screening until corrected age allows valid exam.
— Acetabular maturation slower; physiologic immaturity (Graf IIa) more common — repeat ultrasound rather than treat immediately.
— Down syndrome, Ehlers-Danlos, arthrogryposis, Larsen syndrome — different natural history, surveillance imaging often needed beyond infancy.
— Consider residual acetabular dysplasia even with "normal" childhood exam — order AP pelvis + false-profile view; measure center-edge angle.
Board pearl: A neonate delivered by C-section for frank breech, with a completely normal hip exam at discharge and 2-week visit → still requires hip ultrasound at 6 weeks. Normal exam does not override the breech risk factor. This is a classic Step 3 distractor where "reassure" is the wrong answer.
— Persistent dislocation → Trendelenburg gait, leg-length discrepancy, lumbar hyperlordosis, low back pain.
— Early-onset osteoarthritis — most patients with untreated dysplasia develop disabling arthritis by 30s–50s.
— Labral tears (extremely common in dysplastic hips, often missed source of groin pain in young adults).
— Secondary scoliosis from pelvic obliquity.
— Functional impairment, decreased athletic participation, psychosocial impact in adolescents.
— Femoral nerve palsy (excessive flexion) — loss of active knee extension; reversible with strap adjustment.
— Brachial plexus injury from shoulder strap pressure.
— AVN of femoral head (1–10%) — most feared.
— Skin breakdown in groin and popliteal creases.
— Pavlik disease — posterior acetabular erosion when harness is continued on an unreduced hip beyond 3–4 weeks.
— AVN of the femoral head — overall risk 5–25% depending on age, surgery type, and force of reduction; minimized by gentle reduction within the safe zone.
— Redislocation/subluxation.
— Residual acetabular dysplasia requiring later osteotomy.
— Cast complications: pressure sores, compartment syndrome (especially after osteotomy with swelling), neurovascular injury, "cast syndrome" (SMA syndrome) in older children — abdominal distension and bilious emesis after spica.
— Infection at surgical sites.
— Leg-length discrepancy requiring shoe lift or epiphysiodesis.
— Limited hip ROM, especially internal rotation and abduction.
— Femoral head deformity (coxa magna, coxa plana) from AVN.
— Early THA — technically more difficult, earlier revision.
CCS pearl: A 2-year-old in spica cast post-closed reduction presents with bilious vomiting and abdominal distension → suspect superior mesenteric artery (cast) syndrome. Orders: NG decompression, IV fluids, NPO, urgent orthopedics consult to bivalve/window the cast, surgery consult if persistent.
— Any positive Ortolani or Barlow on neonatal exam.
— Persistent equivocal exam at 2-week follow-up.
— Limited hip abduction or Galeazzi sign at any age.
— Confirmed dysplasia/dislocation on ultrasound or radiograph.
— Toddler with painless limp, Trendelenburg gait, or limb-length discrepancy.
— Irreducible dislocation in a newborn (suggests teratologic — workup for syndromic causes).
— Acute neurologic deficit (femoral nerve palsy) in an infant in a Pavlik harness.
— Operative cases: closed/open reduction, osteotomies (typically 1–3 day admission for pain control, spica cast application, neurovascular checks).
— Post-spica complications: SMA syndrome, suspected compartment syndrome, severe pressure sores, infection.
— Failure to tolerate oral intake after surgery.
— Inadequate pain control or family unable to manage spica care at home.
— Rare in isolated DDH surgery; consider for children with significant comorbidities (severe CP, cardiac disease) undergoing extensive osteotomies.
— Massive blood loss from pelvic osteotomy in adolescents/PAO.
— Pediatric orthopedics — primary.
— Genetics — when associated with multiple anomalies (Larsen, arthrogryposis, skeletal dysplasia).
— Physical therapy — post-cast removal for range-of-motion recovery and gait training.
— Social work / case management — spica cast home setup, car seat, equipment, school accommodations.
— Child life — older children undergoing spica casting.
— Adolescents with residual dysplasia → transition to adult hip-preservation/arthroplasty surgeon.
— Communicate prior surgical history, AVN status, and remaining acetabular dysplasia clearly.
Step 3 management: Outpatient referral is the rule. The only "emergency" scenarios are operative complications (compartment syndrome, SMA syndrome, infection) or neurovascular compromise in a harness/cast. A newborn with positive Ortolani goes to the pediatric orthopedist's office, not the ED.
— DDH — painless, progressive, exam-driven diagnosis.
— Septic arthritis of the hip — febrile, refusal to bear weight, pseudoparalysis; surgical emergency. Kocher criteria: fever >38.5, WBC >12k, ESR >40, refusal to bear weight.
— Transient synovitis — postviral, low-grade or no fever, improves over days; diagnosis of exclusion vs septic arthritis.
— Osteomyelitis (proximal femur) — focal tenderness, elevated inflammatory markers, MRI confirms.
— Toddler's fracture of tibia — limp without obvious trauma, point tenderness; not hip but commonly confused.
— Legg-Calvé-Perthes disease — idiopathic avascular necrosis of the femoral head, ages 4–8, boys, painless or activity-related limp, decreased abduction/internal rotation. AP/frog-leg pelvis shows sclerosis, fragmentation.
— Transient synovitis still common.
— Juvenile idiopathic arthritis — morning stiffness, multiple joints.
— Slipped capital femoral epiphysis (SCFE) — overweight adolescent, hip/knee/thigh pain, obligate external rotation with hip flexion (Drehmann sign). Frog-leg lateral confirms slip. Non-weight-bearing immediately; surgical pinning urgent.
— Sports-related apophyseal avulsions, labral tears (often on residual dysplasia background), femoroacetabular impingement.
— Neuromuscular hip dysplasia (CP) — separate surveillance pathway.
— Trauma, child abuse — always consider when injury inconsistent with history.
Key distinction: Painless limp with normal labs in a young child → think DDH (if young) or Perthes (if 4–8 years old). Painful limp + fever + refusal to bear weight → septic arthritis until proven otherwise. Adolescent + hip/knee pain + externally rotated leg → SCFE — get a frog-leg lateral.
— Soft "ligamentous" clicks without instability — very common, especially in first weeks; no clunk of relocation. Reassurance only.
— Graf type IIa hips (alpha 50–59°) in infants <3 months — represent slow-maturing but normal hips.
— Repeat ultrasound at 6 weeks; most normalize without treatment.
— Nonspecific; ~20% of normal infants have asymmetric folds. Sensitive but not specific for DDH.
— Hemihypertrophy (consider Beckwith-Wiedemann, Russell-Silver — separate workup for Wilms tumor surveillance).
— Posttraumatic growth arrest.
— Congenital short femur, proximal focal femoral deficiency.
— Cerebral palsy with spastic hip displacement.
— Spinal dysraphism (myelomeningocele) — hip dysplasia common; check back for sacral dimple, hairy patch, tuft.
— Muscular dystrophy in older boys — Gowers sign, hip-girdle weakness.
— Ehlers-Danlos — generalized ligamentous laxity, recurrent dislocations of multiple joints.
— Larsen syndrome — multiple congenital dislocations, flattened facies.
— Arthrogryposis — multiple joint contractures, teratologic hip dislocations often irreducible.
— Skeletal dysplasias — achondroplasia, MED, SED.
— Neonatal septic arthritis of the hip — rare but devastating; can destroy femoral head and produce a dislocation that looks like DDH on later imaging. Suspect with sepsis history, NICU stay, prior hip aspiration.
Board pearl: A 9-month-old with bilateral irreducible hip dislocations, flat facies, and multiple joint dislocations — think Larsen syndrome, not classic DDH. Management requires multidisciplinary care including airway evaluation (cervical spine instability) before any orthopedic surgery under anesthesia.
— Wean to nighttime/nap wear for additional weeks once ultrasound normalizes.
— Serial AP pelvis radiographs at ~6 months, 1 year, 2 years to monitor acetabular index and ossific nucleus development.
— Continue radiographic surveillance until skeletal maturity — residual dysplasia in 10–30% may need later osteotomy.
— Spica cast 3–4 months, transition to abduction brace for additional months.
— Radiographs at cast removal, then every 6–12 months.
— Monitor for AVN (most evident 12–18 months post-reduction): coxa magna, lateral subluxation, growth disturbance.
— Watch acetabular index — failure to remodel to <25° by age 4–5 suggests need for pelvic osteotomy.
— Annual AP pelvis through age 8.
— Less frequent thereafter unless symptomatic or abnormal.
— Re-image at adolescence with measurement of center-edge angle, acetabular index, Tönnis angle.
— Symptomatic dysplasia → consider PAO before joint degeneration sets in.
— Asymptomatic mild dysplasia → counsel on activity, weight maintenance, monitor.
— Low-impact aerobic exercise (swimming, cycling) preferred over high-impact running/jumping in patients with residual dysplasia or post-AVN.
— Weight management — every kilogram amplifies hip load.
— No specific contraindication to most childhood sports after successful treatment, but communicate long-term risk.
— Risk of DDH in future siblings 6%; in offspring 12%; in offspring if parent also affected ~36%. Recommend screening ultrasound in newborn siblings.
Step 3 management: A 5-year-old with treated DDH at age 3 months returns with acetabular index of 28° on routine surveillance — refer to pediatric orthopedics for consideration of pelvic osteotomy to correct residual dysplasia before joint degeneration. "Continue observation" is wrong once acetabular remodeling has failed.
— Orthopedic visit at 1–2 weeks with ultrasound to confirm reduction.
— Weekly to biweekly visits for strap adjustment as infant grows.
— Total harness duration typically 2–4 months.
— Ultrasound to confirm acetabular maturation before discontinuation.
— Cast change at ~6 weeks under anesthesia.
— Total cast duration ~3–4 months.
— Transition to abduction brace 8–12 hours/day or nighttime for additional months.
— AP pelvis radiograph at cast removal and every 3–6 months for the first year, then annually.
— Acetabular index — should decrease with growth: <30° at 6 months, <25° at 1 year, <22° at 4 years.
— Center-edge angle of Wiberg (in older children) — normal >25° in adolescents.
— Ossific nucleus appearance and growth — delayed or asymmetric appearance can signal AVN.
— Shenton line continuity.
— Post-spica: gradual reintroduction of weight-bearing; PT focused on hip ROM, especially abduction and internal rotation; gait training.
— Older children post-osteotomy: protected weight-bearing per surgeon, progression over weeks; quadriceps and abductor strengthening.
— Gross motor milestones (sitting, crawling, walking) may be transiently delayed during/after spica casting but typically catch up within months.
— Reassure parents — language, fine motor, social development are unaffected.
— Specialized car seats for spica casts (many regions have loaner programs).
— Spica chairs, modified strollers, waterproof cast liners.
— School/daycare accommodations if applicable.
— Caregiver burden is significant during prolonged casting; screen for parental stress, postpartum depression in mothers of affected infants.
CCS pearl: When closing a DDH case in CCS, ensure the order set includes: pediatric orthopedics follow-up in 1–2 weeks, repeat hip ultrasound, parental education on harness/cast care, developmental surveillance, and counseling on hip-healthy swaddling for future siblings.
— Parents provide consent for screening, imaging, and treatment.
— Discuss treatment options (Pavlik vs observation in borderline cases, surgical alternatives), risks of treatment (AVN, nerve palsy, redislocation), and risks of non-treatment (early osteoarthritis, gait disorder).
— Document understanding in age-appropriate language; use professional medical interpreters when needed — not family members, particularly not older siblings or the patient's own children later in life.
— DDH is one of the most frequently litigated pediatric orthopedic conditions.
— Failure to perform/document hip exams, failure to screen high-risk infants (breech, family history), failure to image when indicated, or failure to refer positive exam findings are recurring themes.
— Document the exam at every well-child visit — Ortolani/Barlow status, abduction angles, Galeazzi, symmetry of folds. "Hips normal" alone is inadequate.
— Newborn discharged from nursery with positive Ortolani must have documented orthopedic follow-up arranged before discharge — closed-loop communication.
— Premature infants in NICU often miss routine hip exams; ensure follow-up plan at NICU discharge.
— Adolescents with childhood DDH transitioning to adult care need explicit handoff of imaging history and AVN status.
— Not DDH-specific, but suspected non-accidental trauma (NAT) presenting as "limp" in a young child must be reported; metaphyseal corner fractures, posterior rib fractures, and inconsistent history are red flags.
— Counsel against tight extended-leg swaddling and cradleboard practices respectfully; offer hip-healthy alternatives.
— Prefer ultrasound and MRI in young children; use low-dose CT protocols only when necessary; track cumulative radiation exposure.
— Disparities exist in DDH detection — non-English-speaking families, rural patients, and Medicaid beneficiaries are at higher risk for late diagnosis. Build systems (callback for missed ultrasounds, interpreter services) to close gaps.
Board pearl: A 14-month-old with a previously documented "click" at the newborn nursery, no follow-up arranged, now presents with painless limp and limited abduction — this scenario triggers both a clinical workup and a quality/safety event review for closed-loop referral failure. Document, disclose, and report through institutional safety systems.
— 0–6 months: Pavlik harness.
— 6–18 months: closed reduction + spica.
— 18 months–8 years: open reduction ± femoral/pelvic osteotomy.
— Adolescent/adult: PAO or THA.
Step 3 management: When in doubt on a Step 3 vignette — match age to treatment modality and check whether the answer addresses the next best step (often "refer to pediatric orthopedics" or "obtain hip ultrasound") rather than the definitive procedure.
— Female newborn, frank breech at 36 weeks, delivered by C-section. Exam normal. Next step?
— Answer: Hip ultrasound at 6 weeks of age. Distractors: reassure, AP pelvis x-ray now, repeat exam only.
— 2-day-old with palpable clunk on abduction of the right hip. Best next step?
— Answer: Refer to pediatric orthopedics. Distractors: x-ray (too young, femoral head not ossified), MRI, double diapering.
— 6-week-old in Pavlik for 1 week; mother notes the baby is not kicking the right knee. Diagnosis?
— Answer: Femoral nerve palsy from excessive hip flexion. Management: relax flexion or temporarily discontinue harness; expect resolution.
— 14-month-old new to your practice; born by breech, no record of hip screening. Walks with a limp, decreased right hip abduction, Galeazzi positive. Next step?
— Answer: AP pelvis radiograph (now >6 months, ossific nucleus visible) and urgent ortho referral.
— 2-year-old POD #3 from closed reduction and spica casting presents with bilious vomiting, abdominal distension. Diagnosis?
— Answer: SMA (cast) syndrome. Management: NG decompression, IV fluids, bivalve cast.
— 4-month-old with persistent dislocation on ultrasound after 4 weeks of Pavlik. Next step?
— Answer: Discontinue Pavlik; closed reduction under general anesthesia with arthrography and spica casting.
— 16-year-old female with childhood "hip problem"; intermittent groin pain with activity. AP pelvis shows shallow acetabula bilaterally, center-edge angle 18°. Best management?
— Answer: Periacetabular osteotomy (PAO) consultation — joint preservation before arthritic change.
— 7-year-old boy with several weeks of painless limp, decreased internal rotation; afebrile, normal labs. AP pelvis: fragmentation of right femoral head. Diagnosis?
— Answer: Legg-Calvé-Perthes disease, not DDH.
Board pearl: Recurring trap — answering "reassure and follow up" when a clear risk factor (breech, family history, asymmetric abduction, Galeazzi) mandates imaging or referral. When the stem includes a risk factor, the correct answer almost never involves passive observation alone.
Developmental dysplasia of the hip is a spectrum of acetabular underdevelopment and femoral head instability that demands age-stratified detection (Ortolani/Barlow → limited abduction), age-stratified imaging (ultrasound <4–6 months, x-ray >4–6 months), and age-stratified treatment (Pavlik <6 months → closed reduction 6–18 months → open reduction + osteotomies >18 months), with lifelong surveillance to prevent early hip osteoarthritis.
— Screen every well-baby visit through walking age; mandatory ultrasound at 6 weeks for breech ≥34 weeks gestation, female + family history, or any persistent abnormal exam — a normal exam does not override risk factors.
— Match age to treatment: Pavlik harness 0–6 months (abandon if no reduction by 3–4 weeks; watch for femoral nerve palsy), closed reduction + spica 6–18 months, open reduction with femoral/pelvic osteotomy >18 months, PAO or THA in adolescents/adults — and the safe zone of abduction protects against AVN, the most feared complication.
— Know the imaging numbers: Graf alpha ≥60° normal, acetabular index <30° at 6 months and <25° at 1 year, center-edge angle >25° in adolescents; broken Shenton line and Galeazzi sign indicate dislocation (Galeazzi is falsely negative in bilateral disease).
— Differentials by age for the limping child: DDH and septic arthritis in infants/toddlers, Legg-Calvé-Perthes 4–8 years, SCFE in overweight adolescents — and on Step 3, the right answer is usually "refer" or "image" when a risk factor is present, never passive reassurance.
Step 3 management: Treat DDH as a longitudinal, exam-and-imaging-driven diagnosis: document hip exam at every visit, image high-risk infants regardless of exam findings, refer early, surveil radiographically until skeletal maturity, and counsel families on sibling risk, hip-healthy swaddling, and the lifelong importance of monitoring for residual dysplasia and early osteoarthritis.