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🌱 來自: bacterial arthritis

Additional diagnostic studies of bacterial arthritis

• Synovial fluid:
  • WBC usually >50k (Se 62%, Sp 92%) but can be <10k, >90% polys;
  • Gram stain ⊕ in ~75% of Staph, ~50% of GNR;
  • Cx ⊕ in >90%;
  • synovial bx most sens.
• Leukocytosis (Se 90%, Sp 36%);
• elevated ESR/CRP (Se >90%)
• Blood cultures ⊕ in >50% of cases, ~80% when more than 1 joint involved
• X-rays of joints should be obtained but usually normal until after ~2 wk of infection when may see bony erosions, joint space narrowing, osteomyelitis, and periostitis
• CT & MRI useful esp. for suspected hip infection or epidural abscess