Infectious Arthritis: Septic

Question 1

Causative organism
-overall
-sexually active
-sickle cell
Most common location

Presentation

Answer 1

Overall - S aureus
Sexually active - N Gonorrhoea
Sickle cell - salmonella
Hematogenous spread => knee

Acute swollen red hot painful single joint
Fever, systemically unwell

Question 2

Investigations

Answer 2

DEFINITIVE - synovial fluid sampling
Blood culture - due to hematogenous spread
Joint imaging

Question 3

Management

Answer 3

IV ABx - flucloxacillin

• needle aspiration - decompress joint
• arthroscopic lavage if needed

Question 4

Other differentials that are considered after septic arthritis is ruled out

Answer 4

Gout
Pseudogout
Reactive