Septic Arthritis

Question 1

What is septic arthriits?

Answer 1

Infection of the synovial joint –> Arthritis

Question 2

How does septic arthritis originate?

Answer 2

!Haematogenous spread!
Bone Abscess perforates into the joint
Direct via a penetrating wound, intra-articular injury or arthroscopy
!Infected Joint Replacement!

Question 3

What organisms cause Septic Arthritis?

Answer 3

Staph Aureus
H. Influenzae
Strep Pyogenes
E. Coli if under <1month old or UTI history

These are the same as Osteomyelitis so we can treat even if were not sure which or there’s overlap

Question 4

Describe the pathology of Septic Arthritis/

Answer 4

Acute Synovitis + Purulent joint effusion leads to destruction of the articular cartilage then it either:

• Completely recovers
• Develops Osteoarthritis from cartilage loss
• Joint fuses –> Fibrous or bony ankylosis

Question 5

How does Septic Arthritis present in neonates?

Answer 5

Septicaemia + resistance to movement

Question 6

How does septic arthritis present in children/adults?

Answer 6

Acute pain in a single large joint + tenderness, tachycardia, fever & reduced movement

Question 7

How do we test for septic arthritis?

Answer 7

FBC
WCC
ESR & CRP
Blood cultures
X-ray
US
Aspiration

Question 8

Whats the differential for Septic Arthritis?

Answer 8

Acute OM
TRauma
Irritable joint
Haemophilia
Rheumatic Fever
Gout
Gaucher's Disease

Question 9

How do we treat Septic Arthrits?

Answer 9

Supportive - fluids & Analgesia
3-4wks of Abx
Surgical drainage and lavage
Infected joint replacement