Septic Arthritis

Question 1

Septic Arthritis Epidemiology

Answer 1

• S. areus is most frequent pathogen responsible

- Mainly methicillin-sensitive strains

Question 2

Septic Arthritis RFs

Answer 2

• Increasing age
• DM
• Prior joint damage
• Joint surgery
• Skin infection and prosthesis
• Immunodeficiency

Question 3

Septic Arthritis Presentation

Answer 3

• Single swollen joint with pain on active or passive movement
• Can be polyarticular
• Fevers and rigors in majority
• Join swollen, warm, tender and very painful to move
• Chest wall pain if e.g. sternoclavicular
• Buttock, hip or anterior thigh pain if sacroiliac infection
• Easily missed in children, localising signs may be absent and confused with more common conditions

Question 4

Septic Arthritis Differentials

Answer 4

• Gout and pseudo gout
• Arthritis, vasculitis
• Drug induced arthritis
• Reactive arthritis
• Lyme disease

Question 5

Septic Arthritis GBS

Answer 5

-Infection of sternoclavicular and sacroiliac joints

Question 6

Septic Arthritis Gonococcal

Answer 6

• Fever
• Arthralgia
• Skin lesions
• Tenosynovitis

Question 7

Septic Arthritis Lyme Disease

Answer 7

• Swelling disproportionate to pain

- Suspect in those with tic bites or travel to recent endemic area

Question 8

Septic Arthritis Investigations

Answer 8

• FBC (infective markers)
• Synovial fluid examination (ortho)
• At least two blood cultures to exclude bacteraemia
• Gonococcal cultures (rectal, cervical, urethral, pharyngeal)
• X ray joint (as a baseline)
• CT/MRI if diagnostic difficulty

Question 9

Septic Arthritis Management

Answer 9

• Immediately after aspiration and blood cultures
• Empirical antibiotics (consult micro) IV for first 2-3 weeks then oral
• Repeat aspirations