Bone & Joint infections

Question 1

How can septic arthritis occur?

Answer 1

direct inoculation (trauma)
haematogenous spread

Question 2

How does septic arthritis present?

Answer 2

Hot, red, swollen monoarthritis

systemic signs of infection

Question 3

if multiple joints are affected at the same time in septic arthritis, what should you investigate for?

Answer 3

Endocarditis

Question 4

What investigations should be done for septic arthritis?

Answer 4

Full bloods
CRP
Blood culture

Question 5

Management of septic arthritis?

Answer 5

Antibiotics +/- surgical washout

Question 6

What is osteomyelitis?

Answer 6

infection of bone

Question 7

give 2 organisms that can cause acute osteomyelitis?

Answer 7

Staph aureus

Streptococci

Question 8

Give 2 organisms that can cause chronic osteomyelitis?

Answer 8

TB (in the spine)

E. coli

Question 9

How do the organisms manage to infect the bone in osteomyelitis?

Answer 9

Haematogenous spread
Prosthesis
Peripheral vascular disease (slowing of blood flow helps bacterial growth)

Question 10

How does osteomyelitis typically present?

Answer 10

Pain, swelling and erythema over the affected area
Low grade fever
Fatigue and malaise

Question 11

What is the gold standard investigation for osteomyelitis?

Answer 11

Bone biopsy

Question 12

management of osteomyelitis?

Answer 12

IV antibiotics - vancomycin until cultures come back to make it more specific

Question 13

When is a prosthetic joint infection most likely to present?

Answer 13

late (>1 month after operation)

Question 14

How does an early prosthetic joint infection present?

Answer 14

sepsis + warm joint with effusion

Question 15

Causative organisms for early-presenting prosthetic joint infection?

Answer 15

Staph aureus

Question 16

Causative organisms for late-presenting prosthetic joint infection?

Answer 16

Staph. epidermis

Question 17

What helps staph. epidermis be more pathogenic in prosthetic joint infections?

Answer 17

the presence of the prosthesis

Question 18

How do late-presenting prosthetic joint infections typically present?

Answer 18

persistent pain at the joint with prosthesis loosening

Question 19

Management of prosthetic joint infections?

Answer 19

Debridement + antibiotics

Question 20

What causes tetanus and how does it present?

Answer 20

Clostridium tetani - releases toxins

Toxin mediated illness that causes spastic paralysis

Question 21

How do the toxins from clostridium tetani cause symptoms in tetanus?

Answer 21

Toxins prevent neurotransmitter release so muscles are “locked” - can’t relax so progresses to inability to breathe, swallow etc because diaphragm and other muscles cant move

Question 22

Management of tetanus?

Answer 22

Vaccination

Surgical debridement + antitoxin

Question 23

is osteomyelitis more common in adults or children in the absence of previous surgery?

Answer 23

More common in children