Pathophysiology
- Haematogenous spread of microorganism to joint space is more common than direct inoculation
- Microbiology:
- Staph Aureus is the most common causative organism overall
- In young, sexually active adults, non-traumatic septic arthritis is most commonly caused by Neisseria Gonorrhoea
- The most commonly joint is the knee
Clinical features
- A single red, hot, swollen joint
- Severe pain - very limited ROM, including any passive ROM
- Unable to weight bear if lower limbs
- Pyrexia and SIRS
Investigations
- Joint aspiration for MCS
- Blood cultures
Management
- 1st Line:
- Flucloxacillin – total course 4-6 weeks
- Penicillin allergy: Clindamycin
- Alternatives:
- If MSRA suspected - vancomycin (or teicoplanin)
- If gonococcal arthritis (or gram negative) suspected - cefotaxime
- Plus – needle decompression +/- lavage