Osteomyelitis

Question 1

What are the four main causes of osteomyelitis?

Answer 1

1. Surgery
2. Diabetes
3. Peripheral vascular dz
4. Trauma

Question 2

What would clue you into an osteomyelitis with a hematogenous spread?

Answer 2

• single bone
• metaphysis
• no single obvious site
• single pathogen isolate
• Usually in the tibia or femur

Question 3

What is the clinical presentation of someone with osteomyelitis?

Answer 3

1. fever/chills/malaise

2. restricted movement, pain/tenderness in neck/back (90%)

Question 4

What are common pathogens in vertebral osteomyelitis?

Answer 4

1. Staph aureus
2. Viridans strep
3. enterococci
4. E. Coli
5. Salmonella in a SICKLE CELL pt

Question 5

What are risk factors for vertebral osteomyelitis?

Answer 5

1. Age>50
2. Sickle cell dz
3. diabetes
4. hemodialysis
5. trauma
6. UTI

Question 6

How do you diagnose vertebral osteomyelitis?

Answer 6

1. positive cultures
2. X Rays (erosion of end plates)
3. CT/MRI scan for abscesses

Question 7

What are the two types of contiguous focus osteomyelitis?

Answer 7

with and without vascular insufficiency. If vascular insufficiency is present, SMALL BONES OF FEET involved.

Question 8

What pathogen is common in contiguous focus osteomyelitis?

Answer 8

Staph aureus! Often polymicrobial or gram - aerobic (pseudomonas)

Question 9

What bug affects prostheses?

Answer 9

coagulase negative staph

Question 10

What labs are relevant in osteomyelitis?

Answer 10

1. blood culture
2. ESR
3. CRP (acute phase protein)

Question 11

How long do you treat osteomyelitis for?

Answer 11

Either 4-6 weeks or until CRP is normal or ESR < 2/3 of entering value.

–always culture before starting antimicrobial therapy!

Question 12

When will you see X ray changes in cases of osteomyelitis?

Answer 12

After 10 days of infection, usually in periosteum. If you see lytic changes, it’s been 2-6 weeks

Question 13

What other imaging could you use?

Answer 13

1. Radionuclide scan has high sensitivity. All 3 phases positive
2. Scintigraphy: Labeled WBC study. See if SBC goes to bone. More specific for osteomyelitis
3. MRI is most sensitive AND specific. Detects changes early.
   - ->All of these help with differentiating between soft tissue versus bone involvement.

Question 14

Should you treat empirically in osteomyelitis?

Answer 14

YES=can gram stain for treatment. Usually include S aureus coverage

Question 15

Cultures of a patient with osteomyelitis show Staph aureus. What would you use to treat if the patient is allergic to penicillins?

Answer 15

Cefazolin, ceftriaxone, or clindamycin

Question 16

What would you use to cover osteomyelitis with GNR on gram stain?

Answer 16

Ampicillin/Ceftriaxone/Cipro depending on sensitivity

Question 17

What would you use if the pt had pseudomonas osteomyelitis?

Answer 17

Aminoglycosides or quinolones

Question 18

How do you treat chronic osteomyelitis?

Answer 18

1. MRI/CT
2. Debridement of bone/soft tissue
3. 4-6 weeks of Abx

Question 19

How do you treat osteomyelitis in a pt with vascular insufficiency?

Answer 19

Make sure to revascularie limbs and provide surgical debridement

Question 20

What other unusual organism do you have to worry about in a pt with osteomyelitis and a cough?

Answer 20

TB–Pott’s disease with granulomas forming in the bone