Septic arthritis

Question 1

Define septic arthritis

Answer 1

Infection of a joint

Question 2

What is presentation of SA?

Answer 2

Pain, redness, swelling, and loss of function in a joint occuring acutely

Fever

Affects knee in 50% cases

Question 3

What are risk factors for SA?

Answer 3

Pre-existing joint disease
Immunocompromised 
renal failure
diabetes
IVDU
recent joint surgery and prosthetic joints 
TB

Question 4

What are causative organisms in SA?

Answer 4

Staph aureus
N gonorrhoea
Haemophilus

Question 5

What are differentials in SA?

Answer 5

Gout or CPPD
Trauma e.g. haemarthrosis
Early presentation of OA, RA

Question 6

Ix for SA?

Answer 6

1. Joint aspirate: gram stain and sensitivities, culture, light microscopy, WCC
2. Blood cultures
3. Any other cultures

Bloods: FBC, WCC, CRP, uric acid to exclude gout .

Imaging likely to be normal, but can be done to exclude other.

Question 7

What are CI to joint aspiration?

Answer 7

Overlying cellulitis
Non-native joint
Open wound
Deranged coag

Question 8

What is treatment of SA?

Answer 8

GIVE ABX EMPIRICALLY once swabs and joint aspirate done. Then change once sensitivities known. IV for 2 weeks, orally for 4.

Native joint: daily aspiration on ward
Prosthetic joint: surgical washout and debridement in theatre

Question 9

What are complications of SA?

Answer 9

Sepsis
OA
Osteomyelitis