Bone and Joint infection 18/10/18

Question 1

What are the five principles of inflammation?

Answer 1

Tumour
Rubor
Dolor 
Calor
Functiono Laesa

Question 2

What blood tests are useful?

Answer 2

CRP

Plasma Viscosity

Question 3

What imaging is useful to diagnose infection?

Answer 3

X-ray
MRI
Technetium scan

Question 4

What is the only thing that can properly diagnose the infection?

Answer 4

Surgically getting a specimen of the organism

Question 5

What does a bone scan show?

Answer 5

Increased osteoblast activity

Question 6

What can an MRI show in bone infection?

Answer 6

Fluid

Abscess

Question 7

What is more useful MRI or X-ray?

Answer 7

MRI

Question 8

What is the most common cause of osteomyelitis?

Answer 8

Post traumatic/Open fracture

Innoculation

Question 9

What kind of osteomyelitis may occur in children and the immunosuppressed?

Answer 9

Haematogenous

Question 10

What are some infecting organisms causing osteomyelitis?

Answer 10

Staph aureus

Haemophilus in children

Question 11

What imaging is better for osteomyelitis?

Answer 11

MRI

Can show changes before x-ray

Question 12

What must happen when pus is present?

Answer 12

Let it out

Question 13

How does osteomyelitis occur?

Answer 13

Damage to endothelial vessels in bone - thrombus forms - bacteria settles

Question 14

What are the two paths of chronic osteomyelitis?

Answer 14

Sclerotic reaction
Pus goes in different directions
-Into joint = septic arthritis
-Into periosteum = bone death over a wider area, new bone begins to form under pereosteum

Question 15

What is useful for treating and diagnosing chronic osteomyelitis?

Answer 15

Blood tests are unhelpful

Plain X-ray and MRI

Question 16

Do patients with chronic osteomyelitis require surgery?

Answer 16

Not always

Only if curative

Question 17

What is involucrum?

Answer 17

Bone forming under periosteum?

Question 18

How can septic arthritis begin?

Answer 18

From inoculation
From metaphyseal spread
Direct haematogenous

Question 19

What is the patchy appearance (mottled) on x-ray?

Answer 19

Gas

Question 20

What does gas on x-ray suggest?

Answer 20

Necrotising fascitis

Question 21

How is cellulitis diagnosed and treated?

Answer 21

Can’t get a sample as no pus

Guess antibiotics to cover staph and strep

Question 22

What 2 antibiotics can be used for cellulitis?

Answer 22

Flucloxacillin

Benzylpenicillin

Question 23

How is necrotising fascitis treated?

Answer 23

SURGERY

Antibiotics to follow but will not cure

Question 24

What is discitis?

Answer 24

Septic arthritis within the disc space

Question 25

When are best guess antibiotics okay to use?

Answer 25

When obtaining a sample would be too difficult

When there is a large chance of a certain organism (staph) being the cause

Question 26

How common is infected arthroplasty?

Answer 26

Should be no more than 1%`

Question 27

What are two questions for infected arthroplasty?

Answer 27

Was there ever a wound problem

Has it ever been pain free

Question 28

What are tests for infected arthroplasty?

Answer 28

CRP
Joint aspiration
Bone scan
X-ray

Question 29

What is the presentation of an infected joint replacement?

Answer 29

Low grade
Slightly hot
Slight niggling pain

Question 30

How successful are the one and two stage revsion surgeries for infected joint replacement?

Answer 30

1 stage - 70-80%

2 stage - 80-90%

Question 31

What is prophylaxis for surgery to prevent infection?

Answer 31

Clean air theatres
Laminar flow
Local antibiotics - 24 hours before
Systemic antibiotics - in cement
Duration of surgery

Question 32

What antibiotics may be used as prophylaxis?

Answer 32

Co-amoxiclav
Flucloxacillin + Gentamicin
Clindamycin
Co-Trimoxazole