infectious arthritis in the elderly

Etiology

• most common causative organisms
  • Staphylococcus aureus
  • Streptococcus
  • gram negative bacilli increasing in frequency
• risk factors
  • cancer
  • immunosuppression
  • chronic illness
    • diabetes mellitus (24% of patients)
    • chronic renal failure
  • prosthetic joint surgeries
  • chronic arthritis
  • recent procedures

Pathology

• knee is most common joint

Clinical manifestations

• frequently afebrile
• joint out of sync
• (see infectious arthritis)

Laboratory

• complete blood count - WBC is often normal on presentation
• erythrocyte sedimentation rate (ESR)
  • usually elevated
  • average value 79 mm/hr

Radiology

• 71% have radiologic evidence of pre-existing joint disease

Complications

• 38% develop osteomyelitis
• 19% mortality due to sepsis

Differential diagnosis

• sexually transmitted disease
• cellulitis
• regional sympathetic dystrophy (RSD)
• bursitis
• osteomyelitis
• crystalline arthropathy (gout, pseudogout)

Management

see infectious arthritis

More general terms

• infections in the elderly
• infectious arthritis (septic arthritis)