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Zorluk: OrtaOrthopedic Surgery

A mother brings her 3-year-old son to an urgent care clinic because he has been crying inconsolably whenever she tries to change his diaper or move his right leg. Since yesterday morning, the child has refused to stand or walk. He had a runny nose and low-grade fever two weeks ago, which resolved without medication. Today, his temperature is 38.8∘C38.8^\circ\text{C} (101.8∘F101.8^\circ\text{F}), pulse is 110/min110/\text{min}, and blood pressure is 90/60 mmHg90/60\text{ mmHg}. Physical examination reveals a distressed child who holds his right leg flexed, abducted, and externally rotated at the hip joint. Any attempt to internally rotate the right leg causes severe guarding and screaming. Laboratory analysis reveals a leukocyte count of 17,500/mm317,500/\text{mm}^3 and an erythrocyte sedimentation rate of 52 mm/h52\text{ mm/h}. Plain radiographs of the pelvis and bilateral lower extremities demonstrate no fracture, dislocation, or evidence of avascular necrosis. Which of the following is the most appropriate next step in the evaluation and management of this patient?

  1. Ultrasound-guided aspiration of the right hip jointCevap
  2. B
    Immediate administration of intravenous cefazolin and vancomycin
  3. C
    Magnetic resonance imaging of the right hip and pelvis
  4. D
    Reassurance, oral ibuprofen, and discharge home with close follow-up
  5. E
    Application of a spica cast and strict bed rest

Cevap

The correct answer is ultrasound-guided aspiration of the right hip joint.
The correct answer is ultrasound-guided aspiration because the patient meets all four Kocher criteria for septic arthritis: fever greater than 38.5∘C38.5^\circ\text{C}, inability to bear weight, ESR greater than 40 mm/hr40\text{ mm/hr}, and a serum WBC count greater than 12,000/mm312,000/\text{mm}^3. This constellation of findings carries a greater than 99% probability of septic arthritis. Immediate aspiration of the synovial fluid is the critical next step to obtain a cell count, Gram stain, and culture to definitively diagnose the infection and guide targeted antimicrobial therapy.

Adım Adım Çözüm

1
Analyze the patient's clinical presentation.
The patient is a child presenting with acute-onset inability to bear weight, high fever, and a hip held in flexion, abduction, and external rotation (the position of maximum joint volume).
These findings are highly suspicious for an acute inflammatory or infectious process in the hip joint.
2
Evaluate the laboratory findings using the Kocher criteria.
The patient meets all four criteria: non-weight-bearing, temperature > 38.5 C, ESR > 40 mm/hr (patient has 52), and WBC count > 12,000/mm3 (patient has 17,500).
The Kocher criteria differentiate septic arthritis from transient synovitis. Meeting 4 out of 4 criteria yields a >99% probability of septic arthritis.
3
Determine the definitive diagnostic and initial management step.
The most appropriate next step is an ultrasound to confirm a joint effusion, immediately followed by arthrocentesis (aspiration).
Synovial fluid must be obtained for cell count, Gram stain, and culture prior to initiating any antibiotic therapy to ensure the correct pathogen is targeted.

Anahtar Kavram

Pediatric septic arthritis management and Kocher criteria
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Orthopedic Surgery

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