6- Bone Infections Flashcards Preview

MSS > 6- Bone Infections > Flashcards

Flashcards in 6- Bone Infections Deck (21)
1

Results from seeding of bone rleated to previous bacterimia

Hematogenous

2

Osteomyelitis From penetrating injury

Direct implanation

3

Osteomyletis from direct spread of bacteria overlying wound or ulcer

Contigous

4

osteomyelitis from prosthetic infection material implanted in bone, spread of organisms to adjacent bone

Infection of prosthetic device

5

More common osteomyletisi in children?

Hematogenous

6

MOre common osteomylitis in adults

contigous and prosthetic infection

7

Common pathogen involved in direct implantation osteomyletis

P. Aeroginosa

8

Key pathogens for Hematogenous osteomyletis

Staphylococcus aureus, Streptococcus sp., 
gram-negatives, Mycobacterium tuberculosis, Salmonella sp. 
(in sickle cell patients).

9

Pathogens for direct implant?

Pseudomonas aeruginosa in nail injuries 
with sneakers

10

Key pathogens for contiguous osteomyelitis

S. aureus, gram-negatives, Streptococcus sp., 
anaerobes, Candida sp. 

(often dt pressure ulcer)

11

Key pathogens for Prosthetic osteomyelitis

Coagulase negative staphylococci, 
S. aureus, gram-negatives, Streptococcus sp.

12

Some complications of osteomylitis

Often causes chronic infections that are difficult to eradicate.
Damage to the periosteum may result in pieces of dead bone 
(sequestrum) or new external bone formation (involucrum); 
localized abscesses may also occur (Brodie’s abscesses)

13

Whats the most effecting imaging to get for suspected osteomyelitis

X-rays may be negative in early infections and in fact are not 
very sensitive for osteomyelitis; Bone/WBC scans or MRI 
imaging are more effective

14

Where should we get the culture of bacteria for osteomyelitis to make Dx?

The bacteria causing osteomyelitis can be obtained from bone 
biopsies or sometimes from blood cultures

15

What can be tricky about obtaining a culture in someone with contigious osteomyelitis?

Cultures of open ulcers overlying contiguous osteomyelitis are 
notoriously unreliable; the bacteria in the bone underneath 
may be entirely different

16

Why are prosthetic osteomyelitis infections hard to tx

Biofilms can devo and they are resistant to lots of drugs. may need to remove the prosthesis

17

Describe biofilms

The adherent microorganisms are frequently embedded in a matrix that they produce – called slime or extracellular polymeric substance or glycocalyx.
The biochemistry and physiology of biofilm organisms are different from those of planktonic (suspended) organisms

18

What drug is a good tx for biofilms

Rituximab

19

Recommened tx for osteomyeltis infection?

Osteomyelitis treatment requires long courses of antibiotics; 
generally 6 weeks of intravenous therapy is used, but in some 
cases months of oral antibiotics may also be required 
(particularly for prosthetic joint infections)

20

If antibiotics fail to clear up osteomyelitis, what would be the next step?

 Surgery may be needed to remove sequestra or prostheses (in 
cases where antibiotics alone fail)

21

What must be present in order to tx an osteomyeltis and prevent reoccurance?

Antibiotic treatment is only useful if the bone is covered by 
tissue - otherwise, new organisms can continuously invade 
the bone.