Osteomyelitis

Question 1

What is Osteomyelitis?

Answer 1

Infection of the bone, either acute or chronic, and classified as either:
—Nonhematogenous
—Hematogenous

Question 2

What are the characteristics of chronic osteomyelitis?

Answer 2

Long standing infection for months to years and:
—Sequestra = pieces of necrotic bone that separate from viable bone
—Presence of a sinus tract

Question 3

What is Nonhematogenous Osteomyelitis?

Answer 3

The result of contiguous spread of infection to bone from adjacent soft tissues and joints via direct inoculation of infection into the bone (trauma/surgery)

Question 4

What is hematogenous osteomyelitis

Answer 4

Caused by microorganisms that seed the bone in the setting of bacteremia

Question 5

What are the complications of osteomyelitis?

Answer 5

—Sinus tract formation
—Contiguous soft tissue infection
—abscess
—septic arthritis
—systemic infection
—bony deformity 
—fracture
—malignancy

Question 6

What are the risk factors for Non Hematogenic osteomyelitis?

Answer 6

—Poor healing soft tissue wound (diabetic ulcer)
—Orthopedic hardware
—DM
—PVD
—Peripheral neuropathy

Question 7

What bacteria is suspected in NH osteomyelitis?

Answer 7

S. aureus, coagulase negative staph, and aerobic gram (-) bacilli

Question 8

What are the sx of NH osteomyelitis?

Answer 8

Acute:
—Gradual onset of dull pain, erythema, tenderness, warmth, and fever

Chronic:
—Same except no fever
—* + draining sinus tract*

Question 9

What labs do you see with NH osteomyelitis?

Answer 9

Leukocytosis in acute cases

Elevated CRP/ESR

Question 10

What do radiographs of NH osteomyelitis look like?

Answer 10

Mottled and moth eaten

Question 11

What Organisms cause Hematogenous Osteomyelitis?

Answer 11

Caused by microorganisms that seed the bone in the setting of bacteremia.

Typically monomicrobial:
—Staph aureus most common
—IVDU= P. Aeruginosa, Serratia marcescenes
—Immunosuppresssed =Aspergillus

Question 12

What area is Hematogenous Osteomyelitis commonly seen?

Answer 12

Children: common, primarily of the long bones

Adults: vertebral osteomyelitis is most common, least common is long bones of appendicular skeleton

Question 13

What age groups do you commonly see Hematogenic Osteomyelitis in?

Answer 13

Usually >50 yo unless IVDU you will see in <40 yo

M>F

Question 14

What are risk factors for Hematogenous osteomyelitis

Answer 14

—Endocarditis
—Oresence of indwelling intravascular devices or orthopedic hardware
—IVDU
—hemodialysis
—SSD

Question 15

What forms of Hematogenous Osteomyelitis are there?

Answer 15

Vertebral, sternoclavicular, long bone, and emphysematous

Question 16

What is a Brodie Abscess?

Answer 16

In Hematogenous Osteomyelitis: a region of suppuration and necrosis encapsulated by granulation tissue within a rim of sclerotic bone

Question 17

How is Osteomyelitis Diagnosed?

Answer 17

Clinical and radiographic findings + Culture

If a culture/biopsy is not feasible::: findings + persistently elevated inflammatory markers

Question 18

What is the test of choice when you suspect Osteomyelitis and the pt is diabetic and Sx referable to the foot?

Answer 18

MRI

If metal hardware precludes MRI or CT= Nuclear study

Question 19

How do you identify the causative pathogen in Osteomyelitis?

Answer 19

Best accomplished by bone biopsy.

Obtain at least 2 specimens

Question 20

What is on the differential for Osteomyelitis ?

Answer 20

—soft tissue infection
—Charcot arthropathy
—Osteonecrosis (avascular necrosis of bone)
—Gout
—Fracture
—Bone tumor
—Sickle cell crisis
—Complex Regional Pain Syndrome CRPS

Question 21

What is the treatment for NH Osteomyelitis?

Answer 21

Operative debridement for removal of necrotic material and culture of involved tissue/bone.
Followed by antimicrobial therapy for eradication of infection for at least 6 weeks following the last debridement

Cover against MRSA and gram (-) organisms:
—Vancomycin + 3rd or 4th gen cephalosporin

Question 22

What is the treatment for Hematogenous Osteomyelitis?

Answer 22

Parenteral antibiotic therapy and surgery if joint is infected.

Activity against MRSA and aerobic gram (-) bacilli