Septic Arthritis

Question 1

ESSENCE

Answer 1

Infection of 1 or more joints caused by pathogenic microbes, occurs by inoculation or haematogenous spread

Question 2

AETIOLOGY

Risk factors

Answer 2

• Pre-existing joint disease
• Joint prosthesis
• IV drug misuse
• HIV infection
• Immunosuppresive medication
• Alcohol use disorder
• Diabetes
• Recent joint surgery

Question 3

CLINICAL FEATURES

Presentation

Answer 3

• Hot, swollen, painful, restricted joints
  
  • If weight bearing most cannot walk
• Acute presentation (symptoms <2 weeks)
• Fever (60% cases)

Question 4

INVESTIGATIONS

First choice

Answer 4

• Synovial fluid microscopy, gram stain and polarising microscopy
• Synovial fluid culture
• Synovial fluid WCC
• Bloods
  
  • Culture
  • WCC
  • ESR
  • CRP
  • U&E
  • LFT
• X-ray
• US - effusion

Question 5

MANAGEMENT

General principles

Answer 5

• If systemic involvement start sepsis protocol and inform seniors
• If no systemic involvement and prosthetic joint refer to ortho for surgery
• If no systemic involvement and native joint
  
  • Inaccessable joint - refer to ortho for US guided aspiration
  • Accessible - empirical antibiotics, joint aspiration and analgesia

Question 6

COMPLICATIONS

Answer 6

• Antibiotic associated allergic reaction
• Osteomylitis
• Joint destruction