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Flashcards in Osteomyelitis Deck (28):
1

What are the two ways bone can be infected?

Contiguous osteomyelitis (direct extension)
Hematogenous osteomyelitis (seeded by a bacteremia)

2

What are the two clinical presentations of osteomyelitis?

Acute osteomyelitis (cure possible by antimicrobials alone)
Chronic osteomyelitis (refractory to cure by antimicrobials alone)

3

What are two distinct goals of therapy for osteomyelitis?

cure vs suppression

4

Contiguous osteomyelitis is often seen in the context of bone injury and _________

skin ulceration

5

How does diabetes predispose to osteomyelitis

peripheral neuropathy--> soft tissue and bone injury
venous insufficiency--> decreased healing, less able to get antibiotics to the site of wound

6

Differentiate the sites of involvement of hematogenous osteomyelitis in children vs adults

Pediatrics: long bones (different capillary structure around growth plates in children)

Adults: spine, sternoclavicular joint, pubis symphysis

7

What are the most common etiologic agents of osteomyelitis in neonates vs adults

 Neonates: streptococci, S. aureus
 Adults: S. aureus, Gram-negative rods

8

How does host response contribute to the pathology of osteomyelitis?

neutrophilic response--> tissue breakdown
pus in vascular channels--> impedence of bloodflow--> local ischemia--> bone necrosis

= dead bone with thrombosed blood supply

9

Diabetic foot infections that lead to osteomyelitis are often _____

polymicrobial- gram +, gram -, anaerobes

10

______ is the most frequently isolated organism in osteomyelitis

S. aureus

11

Orthopedic devices are associated with osteomyelitis caused by _________

Staph epidermidis, coagulase negative

12

Bites are associated with osteomyelitis caused by ______

streptococci or anaerobes, Pasteurella

13

Nosocomial infections are associated with osteomyelitis caused by ______

enterobacteriacaea

14

Inoculation through the sole of a tennis shoe is associated with osteomyelitis caused by _____

Pseudomonas

also IVDU, malignant otitis externa

15

Sickle cell disease is associated with osteomyelitis caused by _______

Salmonella

16

_______ formation is an external hallmark of osteomyelitis

sinus tract, can spontaneously come and go

17

Acute osteomyelitis is a ______ disease, chronic osteomyelitis is a ______ disease

antibiotic, surgical

18

What lab findings are supportive of a diagnosis of osteomyelitis?

anemia of chronic disease
ESR/ CRP elevated

19

What findings will be seen on plain radiographs in osteomyelitis?

Destruction, periosteal elevation, focal osteopenia

** X rays lag about 2 weeks behind infection, cannot always distinguish from trauma

20

_____ has excellent sensitivity but limited specificity in helping to support a diagnosis of osteomyelitis

MRI

21

CT scans are best for imaging ______ in osteomyelitis

bony sequestra, might need to be surgically removed

22

______ is the gold standard for making a diagnosis of osteomyelitis

bone biopsy

23

Bone biopsy should be done when a patient is off _________ for at least 72 hours

antibiotics

24

Describe the general approach to treating acute osteomyelitis

weeks of IV antibiotics with goal of cure, rarely need surgery

25

Describe the general approach to treating chronic osteomyelitis

surgical debridement is key, followed by mop up antibiotics
goal is suppression, meeting individualized patient needs but not cure

26

It is important to avoid ______ antibiotic therapy in managing osteomyelitis

empiric

27

List some parenteral agents commonly used to treat osteomyelitis

- Nafcillin by continuous infusion (S. aureus)
- Vancomycin (MRSA, coag-negative staph, enterococci)
- Penicillin G by continuous infusion (streptococci)
- Ceftriaxone (streptococci, GNR)
- Cefepime (P. aeruginosa, S. aureus (methicillin-susceptible), mixed)
- Piperacillin/tazobactam by continuous infusion (P. aeruginosa, mixed)

28

List some oral agents commonly used to treat osteomyelitis

- rifampin- never monotherapy
- clindamycin- staph, strep, mixed
- fluoroquinolones- staph, pseudomonas, gram negatives
- TMP/SMX- some MRSA
-minocycline- some MRSA