Osteomyelitis Flashcards
What are the four main causes of osteomyelitis?
- Surgery
- Diabetes
- Peripheral vascular dz
- Trauma
What would clue you into an osteomyelitis with a hematogenous spread?
- single bone
- metaphysis
- no single obvious site
- single pathogen isolate
- Usually in the tibia or femur
What is the clinical presentation of someone with osteomyelitis?
- fever/chills/malaise
2. restricted movement, pain/tenderness in neck/back (90%)
What are common pathogens in vertebral osteomyelitis?
- Staph aureus
- Viridans strep
- enterococci
- E. Coli
- Salmonella in a SICKLE CELL pt
What are risk factors for vertebral osteomyelitis?
- Age>50
- Sickle cell dz
- diabetes
- hemodialysis
- trauma
- UTI
How do you diagnose vertebral osteomyelitis?
- positive cultures
- X Rays (erosion of end plates)
- CT/MRI scan for abscesses
What are the two types of contiguous focus osteomyelitis?
with and without vascular insufficiency. If vascular insufficiency is present, SMALL BONES OF FEET involved.
What pathogen is common in contiguous focus osteomyelitis?
Staph aureus! Often polymicrobial or gram - aerobic (pseudomonas)
What bug affects prostheses?
coagulase negative staph
What labs are relevant in osteomyelitis?
- blood culture
- ESR
- CRP (acute phase protein)
How long do you treat osteomyelitis for?
Either 4-6 weeks or until CRP is normal or ESR < 2/3 of entering value.
–always culture before starting antimicrobial therapy!
When will you see X ray changes in cases of osteomyelitis?
After 10 days of infection, usually in periosteum. If you see lytic changes, it’s been 2-6 weeks
What other imaging could you use?
- Radionuclide scan has high sensitivity. All 3 phases positive
- Scintigraphy: Labeled WBC study. See if SBC goes to bone. More specific for osteomyelitis
- MRI is most sensitive AND specific. Detects changes early.
- ->All of these help with differentiating between soft tissue versus bone involvement.
Should you treat empirically in osteomyelitis?
YES=can gram stain for treatment. Usually include S aureus coverage
Cultures of a patient with osteomyelitis show Staph aureus. What would you use to treat if the patient is allergic to penicillins?
Cefazolin, ceftriaxone, or clindamycin