Septic Arthritis M00

Post op infection image

synonyms: septic joint, joint injection, septic arthritis

Septic Arthritis ICD-10

Septic Arthritis ICD-9

  • 711.__(pyogenic arthritis)

Septic Arthritis Etiology / Epidemiology / Natural History

  • Etiology: hematogenous, IV drug use, trauma, joint aspiration, contigous spread(cellulitis), osteomyelitis
  • Risk Factors: diabetes, rheumatoid arthritis, lupus, HIV, steroid use, malignancy, IV drug use, elderly.
  • Most common organism=S aureus > MRSA. Other causes: Neisseria gonorrhoeae, streptoccoci, E Coli, Pseudomonas, Clostridium. Fungal in HIV patients.
  • Knee (50%), hip (20%), shoulder (10%), ankle (10%), Elbow(5%), Wrist (5%)
  • Glycosaminoglycan degradtion begins within 5 days of infection, cartilage destruction by 7 days, Pannus overgowth @11days, joint capsule erosion @17days, fibrous ankylosis @5weeks.

Septic Arthritis Anatomy

Septic Arthritis Clinical Evaluation

  • Warm, swollen, painful joint
  • Limited ROM
  • May have fever, chills

Septic Arthritis Xray / Diagnositc Tests

  • Labs: ESR, CRP, blood cultures, CBC with differential
  • Best diagnoses with joint aspiration with gram stain, examination for cyrstals, cell count, anaerobic culture, aerobic culture, acid-fast staining.
    -WBC < 2,000mm3: non-inflammatory (SLE, systemic sclerosis, osteoarthritis, Gout.
    -WBC <50,000mm3: infection unlikely
    -WBC 50,000-100,000: concerning; may be seen with TB, gonococcal, immune compromise, partially treated infection, Gout, RA, Reiter's syndrome.
    -WBC >100,000, 75% polymorphonuclear leukocytes: septic knee. (Schmerling RH, JAMA 1990;264:1009).

Septic Arthritis Classification / Treatment

  • Thorough irrigation and debridement either by arthrotomy, or arthroscopy followed by antibiotics for 2-6 weeks determined by culture and sensitivities.
  • Obtain 5 samples and culture for 2 weeks. 
  • Consider Naproxen / NSAID treatment to decrease cartilage loss.
  • Septic Arthritis after knee ligament surgery.

Septic Arthritis Associated Injuries / Differential Diagnosis

Septic Arthritis Complications

Septic Arthritis Follow-up Care

  • Consider referral to infectious disease for antibiotic management in complicated cases or those with drug resistant organisms.
  • Follow responce to treatment with serial ESR and CRP. CRP returns to normal in 1 week, ESR in 3 weeks with adequate treatment.

Septic Arthritis Review References

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