Pediatric Orthopaedic Emergencies in the ED

1. General approach: the limping / non-weight-bearing child

2. Septic arthritis - the orthopaedic emergency you cannot miss

• Epidemiology: twice as common as osteomyelitis in children; two-thirds occur under age 2; boys affected 2x more than girls. Hip and knee each account for about a third of cases.
• Organisms: S. aureus (MSSA > MRSA) predominates across ages; Kingella kingae is increasingly recognized in children under 2, often after an oropharyngeal infection; group B strep/gram-negative enterics in neonates.
• Kocher criteria (fever ≥38.5°C, non-weight-bearing, ESR >40 mm/hr, WBC >12,000/mm³) - probability of septic arthritis of the hip:

• Workup: CBC, ESR, CRP, blood cultures, and definitive joint aspiration for cell count, Gram stain, and culture (inoculate blood culture bottles with synovial fluid to improve yield). A negative Gram stain (occurs in up to 45-71%) should not delay empiric antibiotics.
• Treatment: empiric anti-staphylococcal coverage (e.g., oxacillin/nafcillin or vancomycin if MRSA is a concern) plus urgent orthopedic consultation for surgical drainage, especially of the hip.

3. Slipped capital femoral epiphysis (SCFE)

• Posterior/inferior slippage of the femoral epiphysis on the metaphysis through the growth plate; peak age 8-15 years (avg. 13.5 boys, 12 girls); bilateral in 18-50%.
• Risk factors: obesity (63% of patients ≥90th percentile weight), rapid growth, endocrinopathies (hypothyroidism, GH deficiency, renal osteodystrophy).
• Presents with limp and poorly localized hip, groin, thigh, or knee pain - knee pain referred from the hip is a classic pitfall. Look for limited internal rotation and obligatory external rotation on flexion (Drehmann sign).
• Classified by stability: stable (can ambulate, ~90% of slips) vs. unstable (cannot bear weight even with crutches, higher AVN risk).
• Imaging: AP + frog-leg lateral of both hips (stable) or AP + cross-table lateral (unstable, avoid frog-leg to prevent further displacement). Klein's line (drawn along the superior femoral neck) fails to intersect the epiphysis in SCFE.
• Unstable SCFE is a true orthopaedic emergency - non-weight-bearing, urgent orthopedic consult, and surgical fixation to reduce AVN risk (Rosen's Emergency Medicine, Ch. 170).

4. Supracondylar fracture of the humerus

• The most common pediatric elbow fracture; usually extension-type from a fall on an outstretched hand.
• Undisplaced fractures: collar-and-cuff or backslab, 3 weeks. Displaced fractures often need closed reduction ± percutaneous K-wire fixation if the periosteal hinge is broken.
• Feared complication: Volkmann's ischemic contracture from missed compartment syndrome of the forearm - avoid excessive elbow flexion when swelling is significant, and always document neurovascular status (radial, ulnar, median/AIN nerves; radial pulse) before and after any manipulation.

5. Nursemaid's elbow (radial head subluxation)

• Accounts for >20% of pediatric upper extremity injuries; peak age 1-4 years; classic mechanism is axial traction on a pronated, extended arm (e.g., a caregiver pulling the child's hand).
• Child holds the arm slightly flexed and pronated, refusing to use it, but with no swelling or deformity.
• Reduction by hyperpronation or supination-flexion; hyperpronation has a lower first-attempt failure rate per meta-analysis data. Child typically resumes normal use within 15 minutes.

6. Toddler's fracture

• Nondisplaced oblique fracture of the distal tibia from a minor fall/twist, peak age 1-4 years. History is often vague; child refuses to bear weight without obvious deformity.
• Often radiographically occult initially (thick pediatric periosteum limits displacement); if suspicion is high, immobilize and re-image in ~2 weeks for callus, or consider ultrasound.
• Managed with cast/splint/cast-boot for 3-4 weeks with weight-bearing as tolerated; outcomes are similar across immobilization methods.

7. Non-accidental trauma (NAT) - always keep on the differential

• Roughly 25% of children later diagnosed with NAT had a prior "sentinel injury" that was missed. High-risk group: children <3 years, those with disabilities, and families under socioeconomic stress.
• Skeletal survey (minimum 21 dedicated views, read by an experienced radiologist) is indicated for all suspected-abuse patients <24 months, and considered in the 24-60 month range; a single "babygram" is inadequate. A repeat survey after ≥14 days frequently reveals additional healing fractures missed on the initial study.
• Neuroimaging (CT/MRI) for suspected abusive head trauma, retinal exam + AST/ALT screening, abdominal CT if indicated, and skeletal surveys for siblings/contacts under 24 months are part of a standardized occult-injury workup (Rosen's Emergency Medicine, Ch. 172).
• Characteristic fracture patterns raising concern: classic metaphyseal lesions (corner/bucket-handle fractures), posterior rib fractures, fractures in a non-ambulatory infant, multiple fractures of different ages, and spiral/transverse femur fractures without a clear consistent mechanism.

8. Compartment syndrome

• Most often follows crush injury, long-bone fracture, or reperfusion of an ischemic limb; progressive edema raises tissue pressure above capillary pressure, halting perfusion.
• Frequent serial neurovascular exams are mandatory after any high-risk fracture (supracondylar humerus, tibial shaft) or vascular repair - pain out of proportion, pain with passive stretch, and paresthesias precede pulselessness. Do not wait for all "5 P's" to intervene; fasciotomy is time-critical.

9. Osteomyelitis (frequently co-exists with septic arthritis in children)

• Empiric coverage targets S. aureus (oxacillin/nafcillin or vancomycin if MRSA suspected); standard course is 4-6 weeks IV transitioning to oral. A recent systematic review/meta-analysis (PMID 40001163, 2025) quantifies how often concomitant osteomyelitis occurs in pediatric hip septic arthritis - relevant when deciding on imaging (MRI) and duration of antibiotics for hip infections.