Flashcards in Osteomyelitis Deck (13):
1
What must occur to create osteomyelitis
Negative event like trauma or foreign body or inoculation with biofilm producing or implant adhering infectious agent
2
How is osteomyelitis classified in vet med
Route of infection (hematogenous or post traumatic)
Time of disease onset (acute, subacute, chronic)
3
osteomyelitis time line
1) Acute
2) Subacute
3) Chronic
1) develops within two week
2) develops within several months
3) develops after a few months
4
What is a major predisposing factor in the development of osteomyelitis and how does it occur
Ischemia. Loss of vascular channels (Haversian and Volkmanns canals and canniliculi) secondary to necrosis and resorption during acute inflammatory phase
5
Radiographic evidence suggestive of the aggressiveness of the infection
Less aggressive appears as thickening of the bone
More aggressive shows a lamellated (onion skin) layering
Aggressive calcified streaks perpendicular to the bone
6
What influences the damage from and response to treatment of osteomyelitis
Viability of the bone
Virulence of the infectious orgs
Condition of the soft tissue envelope
7
Where does hematogenous osteomyelitis usually occur
3 reasons why
Metaphysis
sinusoidal capillaries (no basement membrane (BM), discontinuous endothelium/capillary)
Sluggish circulation
No leukocytes in developing spongiosa
8
Most common cause of osteomyelitis and organism
Trauma and Staphylococcal 60% (particularly Staph intermedius
9
4 stages of a biofilm
Reversible attachement, irreversible attachment, growth and differentiation, dissemination or detachment
10
Why are biofilms resistant to antimicrobials
Acts as a filter and barrier
Quiescent growth (If MOA impedes growth and repro its ineffective)
Harsh environment (acidic, increased PCO2 and low PO2)
11
Diagnosis
Biopsy and culture
12
Tx
Drain, debridement (explant), lavage
IV abs (5-7 days) then oral for at least 4 weeks
13