6- Bone Infections

Question 1

Results from seeding of bone rleated to previous bacterimia

Answer 1

Hematogenous

Question 2

Osteomyelitis From penetrating injury

Answer 2

Direct implanation

Question 3

Osteomyletis from direct spread of bacteria overlying wound or ulcer

Answer 3

Contigous

Question 4

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

Answer 4

Infection of prosthetic device

Question 5

More common osteomyletisi in children?

Answer 5

Hematogenous

Question 6

MOre common osteomylitis in adults

Answer 6

contigous and prosthetic infection

Question 7

Common pathogen involved in direct implantation osteomyletis

Answer 7

P. Aeroginosa

Question 8

Key pathogens for Hematogenous osteomyletis

Answer 8

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

Question 9

Pathogens for direct implant?

Answer 9

Pseudomonas aeruginosa in nail injuries
with sneakers

Question 10

Key pathogens for contiguous osteomyelitis

Answer 10

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

(often dt pressure ulcer)

Question 11

Key pathogens for Prosthetic osteomyelitis

Answer 11

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

Question 12

Some complications of osteomylitis

Answer 12

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)

Question 13

Whats the most effecting imaging to get for suspected osteomyelitis

Answer 13

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

Question 14

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

Answer 14

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

Question 15

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

Answer 15

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

Question 16

Why are prosthetic osteomyelitis infections hard to tx

Answer 16

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

Question 17

Describe biofilms

Answer 17

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

Question 18

What drug is a good tx for biofilms

Answer 18

Rituximab

Question 19

Recommened tx for osteomyeltis infection?

Answer 19

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)

Question 20

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

Answer 20

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

Question 21

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

Answer 21

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