Prosthetic joint infection

Question 1

What is a PJI?

Answer 1

This is the infection of an artificial joint and adjacent tissue

Question 2

What is the maximum percentage of prosthetic joints that can get infected according to hospital standards?

Answer 2

1%

Question 3

What are some risk factors for PJI?

Answer 3

• Comorbidities
• Corticosteroids
• Prior infection in joint
• Prolonged duration of surgery
• Bacteraemia

Question 4

What are some comorbidities that increase risk of PJI?

Answer 4

Rheumatoid arthritis
Diabetes
Malignancy

Question 5

What are the 2 most common causative bugs in PJI?

Answer 5

• Staphylococcus aureus (1st)
• Staphylococcus epidermidis (2nd)

Question 6

What is a common bacteria found in upper limb prosthesis?

Answer 6

Cutibacterium acnes

Question 7

What are some gram -ve causes of PJI?

Answer 7

E.coli and pseudomonas aeruginosia

Question 8

What are some methods of contraction in PJI?

Answer 8

Direct involution in surgery
Seeding in bacteraemia

Question 9

What are the 3 classes of PJI?

Answer 9

Early (2-3 weeks)
Chronic (3+ weeks)
Hematogenous (Chronic)

Question 10

What are the most common organisms in early PJI?

Answer 10

staphylococcus aureus
staphylococcus epidermidis

Question 11

What are the most common organisms in chronic PJI?

Answer 11

staphylococcus epidermidis
cutibacterium
corynebacterium
staphylococcus aureus

Question 12

What is the most common organism in haematogenous PJI?

Answer 12

Staphylococcus aureus

Question 13

What types of bacteria are found in PJI?

Answer 13

In PJI, there is a mix of planktonic bacteria, responsible for most symptoms, and sessile bacteria, which adheres to the surface of the joint and forms a biofilm

Question 14

How will PJI usually present?

Answer 14

• Fever
• Joint pain of affected joint
• Minimal swelling
• Sinuses within the skin (Uncommon)

Question 15

What are some tests required in PJI?

Answer 15

• CRP
• Joint aspiration
• Bone scan (Technetium-99)
• X-ray

Question 16

How should early or haematogenous infection be treated?

Answer 16

DAIR:
- D - Debridement
- A - Antibiotics (12 weeks)
- IR - Implant Retention

Question 17

How will chronic PJI be treated in frail patients?

Answer 17

1 stage surgery:
This involves just removal of the joint and antibiotics, leaving the patient with no viable hip joint

Question 18

How will chronic PJI be treated in stronger patients?

Answer 18

2 stage surgery:
This requires removal of the joint and 6 weeks aggressive antibiotic therapy, leaving the patient without a joint for 6 weeks
Once the infection is under control, a revision joint replacement is then performed with more complex joint replacement components

Question 19

What are soem methods of prophylaxis to prevent PJI?

Answer 19

• Clean air theatres (Laminar flow)
• Local antibiotics
• Systemic antibiotics (In cement)
• Hand washing
• Theatre discipline