Septic Arthritis

Question 1

It is an inflammatory condition of the joint caused by bacterial infection, What is the incidence of septic arthritis?

1 - 1.3 : 100,000
2 - 13 : 100,000
3 - 130 : 100,000
4 - 1300 : 100,000

Answer 1

2 - 13 : 100,000

Question 2

It is an inflammatory condition of the joint caused by bacterial infection, What does septic arthritis typically peak at?

1 - 35
2 - 50
3 - 60
4 - >70

Answer 2

4 - >70
- same rates in men and women

Question 3

The most common cause of septic arthritis is a bacterial infection. Which of the following sources can this come from?

1 - blood born from other tissue (lung infection)
2 - osteomyelitis where infection spreads to the joint
3 - open fracture
4 - broken skin
5 - all of the above

Answer 3

5 - all of the above

Question 4

The most common cause of septic arthritis is a bacterial infection. Which bacteria accounts for >90% of septic arthritis cases?

1 - Staphylococcus aureus
2 - Neisseria gonorrhoeae
3 - Candida albicand
4 - Escherichia coli

Answer 4

1 - Staphylococcus aureus

Neisseria gonorrhoeae is most common in young sexually active individuals

Question 5

The most common cause of septic arthritis is a bacterial infection. Which of the following is NOT a typical risk factor for septic arthritis?

1 - Prosthetic joints
2 - RA
3 - SLE
4 - IV drug use
5 - Diabetes mellitus / Immunosuppression
6 - Gender
7 - Chronic skin infections

Answer 5

6 - Gender

Previous inflammation can disrupt the normal joint space, resulting in neovascularisation and increased expression of adhesion factors which facilitates bacterial invasion.

Question 6

Once bacteria get into a joint and lead to septic arthritis, which part of the joint do they target?

1 - meniscus
2 - growth plates
3 - ligaments
4 - articular cartilage

Answer 6

4 - articular cartilage

Question 7

Once bacteria get into a joint and lead to septic arthritis, they begin attacking the articular cartilage. Which cell within the synovial joint then begins to target and destroy the pathogens through recognition of the pathogen associated molecular patterns (PAMPs)?

1 - cytotoxic T cells (CD8)
2 - macrophages
3 - mast cells
4 - neutrophils

Answer 7

2 - macrophages
- inflammatory cytokines are then released

Question 8

Once bacteria get into a joint and lead to septic arthritis, they begin attacking the articular cartilage. Macrophages engulf and phagocytose pathogens and release cytokines that attract immune cells to the site. Which immune cell is also able to recognise pathogen associated molecular patterns (PAMPs) and cause vasodilation and increased vascular permeability?

1 - neutrophils
2 - mast cells
3 - eosinophils
4 - killer cells

Answer 8

2 - mast cells
- release histamines
- increased permeability leads to swollen, red and warm joint

Question 9

Which of the following is NOT a typical sign of a septic arthritis joint?

1 - hot joint
2 - swollen joint
3 - red joint
4 - gangrene joint

Answer 9

4 - gangrene joint

Question 10

Once a joint is infected in septic arthritis, which of the following can occur if the joint is not treated promptly?

1 - increased intra-articular pressure
2 - compression of blood vessels supplying the joint
3 - necrosis of the joint
4 - damaged bones and cartilage, leading to joint destruction
5 - all of the above

Answer 10

5 - all of the above

Question 11

In septic arthritis is it always a singular joint that is affected?

Answer 11

• no
• non-gonococcal arthritis = 1 joint
• gonorrhoeae caused arthritis by Neisseria gonorrhoeae can affect multiple joints

Question 12

Neisseria gonorrhoeae causes septic arthritis in sexually active individuals and can spread hematogenously from the pharynx, cervix or urethra. Which of the following is a clinical sign that the septic arthritis is caused by Neisseria gonorrhoeae?

1 - flu like symptoms
2 - pain and reduced range of movement in multiple joints
3 - multiple skin lesions
4 - tendosynivitis (tendon inflammation)
5 - all of the above

Answer 12

5 - all of the above

This type of septic arthritis only occurs in a small proportion of septic arthritis

Question 13

The most common form of septic arthritis is non-gonococcal septic arthritis, with staphylococcus aureas accounting for >90% of vases. Which if the following is NOT a clinical sign of non-gonococcal septic arthritis?

1 - flu like symptoms
2 - pain and reduced range of movement in both active and passive movement
3 - multiple joints affected
4 - unable to weigh bear
5 - erythematous, hot, swollen and painful joint

Answer 13

3 - multiple joints affected
- only one joint is affected

Question 14

All of the following joints can be affected in septic arthritis, but which joint accounts for aprox 53% of spetic arthritis cases?

1 - hips
2 - knees
3 - shoulders
4 - ankles

Answer 14

2 - knees

Question 15

All of the following are used to diagnose a patient with septic arthritis, but what should be the 1st line for confirming a diagnosis of septic arthritis?

1 - ultrasound of the joint
2 - joint arthrocentesis (sample of joint fluid)
3 - FBC
4 - blood culture (pathogens)
5 - inflammatory markers (CRP/ESR)

Answer 15

2 - joint arthrocentesis (sample of joint fluid)
- also therapeutic by reducing fluid in the joint

Question 16

Joint arthrocentesis (aspiration) is the main method used to confirm a diagnosis, there are occasions when an aspiration should not be performed (relative contraindication). Which of the following is NOT a relative contraindication?

1 - overlying cellulitis
2 - coagulopathy/bleeding disorders
3 - joint affected
4 - joint prosthesis
5 - acute fracture
6 - adjacent osteomyelitis
7 - uncooperative patient.

Answer 16

3 - joint affected

Prosthestic joint aspirations should be done in surgery

Question 17

if the clinician has a high suspicion of septic arthritis, should they delay treating the patient?

Answer 17

• no
• treat as though diagnosis has been made

Question 18

The Kocher criteria can be used to diagnose a patient with septic arthritis. Which of the following is NOT one of these criteria?

1 - fever >38.5 degrees C
2 - raised U&Es
3 - non-weight bearing
4 - raised ESR
5 - raised WCC

Answer 18

2 - raised U&Es

Question 19

Which of the following are likely differentials for septic arthritis?

1 - gout
2 - pseudogout
3 - reactive arthritis
4 - osteoarthritis
5 - psoriatic arthritis

Question 20

When diagnosing and treating septic arthritis, we must rule out bacteraemia or start the septic 6. If there is no prosthetic joint, the patient should be admitted to hospital, the joint should be aspirated and the IV antibiotics should be given. Although it varies between trusts, which is typically the 1st line antibiotic given?

1 - flucloxacillin 2g QDS IV
2 - ceftriaxone 2g QDS IV
3 - vancomyocin 2g QDS IV
4 - gentomyocin 2g QDS IV

Answer 20

1 - flucloxacillin 2g QDS IV
- can change based on culture that comes back

Ceftriaxone should be given if patient is confirmed Neisseria gonorrhoeae

Question 21

Which of the following are complications of spetic arthritis?

1 - joint destruction
2 - sepsis
3 - osteomyelitis
4 - all of the above

Answer 21

4 - all of the above