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20 Cards in this Set
- Front
- Back
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what is osteomyelitis?
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infection of bone that is progressive and results in destruction of bone and new bone formation
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most common organism in osteomyelitis?
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staph aureus
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pathogenesis of osteomyelitis?
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inflammation cause ischemia, necrosis
penetrate cortex, strip periosteum, stimulates new bone formation sequestrum (dead bone) extruded, leads to fistula and sinus tract bacterial adhesin important biofilm important in infected prostheses |
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3 classes of osteomyelitis?
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hematogenous
contiguous vascular insufficiency, diabetes |
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main pt group in acute hematogenous osteomyelitis?
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children (affect long bones)
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what's peculiar about eonate's hematogenous osteomyelitis compared to adults?
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epiphysis open in neonate so infection spreads to joint
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what is brodie's abscess?
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complication of acute osteomyelitis
pus filled cavity surrounded by sclerotic bone |
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what's the manifestation of hemotagenous osteomyelitis in adults?
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vertebral osteomyelitis
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Tx of osteomyelitis?
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IV antibiotics for 4-6 weeks (high dose for bone penetration)
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contiguous osteomyelitis occurs by?
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trauma, surgery, joint replacement
S. aureus most frequent if foreign body infection, think coagulase negative staph |
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chatacteristics of osteomyelitis associated with prosthesis?
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low virulence organisms (coag neg staph)
biofilm formation poor penetration of antibiotics thus surgical remaoval required |
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characteristics of osteomyelitis due to vascular insufficiency?
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mostly in diabetes. - 15% develop foot ulcers.
polymicrobial - staph aur. gram negative, anaerobe |
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microbe/clinical associations
most frequent? foreign body? diabetic foot? sickle cell? sneakers? human/animal bites? nosocomial? endemic population? |
most frequent? staph aur
foreign body? coag neg staph, proprionibacter diabetic foot? s aureus, gram neg, anaerobe sickle cell? salmonella, s. pneumo sneakers? pseudomonas human/animal bites? pasturella, eikinella nosocomial? gram neg endemic population? TB, blasto, histo, cocci |
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Dx of osteomyelitis
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clinical suspicion, Hx, PE
acute - positive blood culture, ESR, CRP Xray bone scan labeled WBC scan (not specific) CT scan MRI **bone biopsy is gold standard |
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most important Dx method in osteomyelitis?
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bone biopsy
do cultures in indicated > 5 PMN per HPF indicate infection |
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Xray shows up in how many days in osteomyelitis?
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10-14 days
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what test needed before biopsy?
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CT scan
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MRI is very good at detecting?
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edema
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Tx of acute osteomyelitis?
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IV antibiotics often sufficient (4-6 wks)
surgery rarely needed - drain intramedullary abscess early switch to oral antibiotics in children switch to oral if poor compliance w/ IV |
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Tx of chronic osteomyelitis?
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bone biopsy to choose pathogen directed therapy
** surgery very important - remove sequestrum, debride high dose IV antibiotics for >6 wks home infusion requires monitoring |
