Septic arthritis

Question 1

What is septic arthritis?

Answer 1

Infection of a joint

Question 2

What organisms commonly cause septic arthritis?

Answer 2

Staphylococcus aureus (most common)
Staphylococcus epidermidis
Streptococcus pyogenes
Neisseria gonorrhoeae
Pseudomonas aeruginosa

Question 3

Which groups of people does pseudomonas septic arthritis occur in?

Answer 3

Immunosuppressed
Elderly
IVDU

Question 4

Which group of patients does staphylococcus epidermidis septic arthritis commonly occur in?

Answer 4

Patients with prosthetic joints

Question 5

Which group of patients does gonococcal septic arthritis commonly occur in?

Answer 5

Young, sexually active people

Question 6

What are the differentials of a single warm swollen joint?

Answer 6

Gout
Pseudogout
Reactive arthritis
Haemarthrosis

Question 7

What is the clinical presentation of septic arthritis?

Answer 7

Hot, tender, erythematous, swollen joint
Difficulty weight bearing
Fever
Limited range of movement

Question 8

What is the definitive investigation in the diagnosis of septic arthritis?

Answer 8

Joint aspiration (with synovial fluid microscopy and culture)

Question 9

What other investigations are useful in the diagnosis of septic arthritis?

Answer 9

Blood cultures - should be performed in all patients before commencing antibiotics
FBC
CRP and ESR
Plain XR

Question 10

What is the initial management of septic arthritis?

Answer 10

Empirical IV antibiotics should be given until sensitivities are known:
- Flucloxacillin - first line
- Clindamycin - penicillin allergy
- Vancomycin - MRSA suspected

Question 11

What is the management of gonococcal arthritis?

Answer 11

Cefotaxime or ceftriaxone