MSK infections

Question 1

What is osteomyelitis

Answer 1

infection of the bone

Question 2

what is the most common cause of osteomyolitis

Answer 2

bacteria and also can be associated with fungi, parasites and viruses

Question 3

what are the mechanisms of spread for osteomyelitis

Answer 3

Hematogenous spread and contiguous spread

Question 4

what patient population is hematogenous spread of osteomyelitis seen in

Answer 4

children and IVDU

Question 5

what comorbidities increases the risk of infection of osteomyelitis

Answer 5

IVDU, peripheral vascular disease, DM and ETOH abuse

Question 6

How does osteomyelitis spread within the bone

Answer 6

spreads through cortex openings

Question 7

what are the two types of osteomyelitis

Answer 7

acute and chronic

Question 8

what is acute osteomyelitis

Answer 8

diagnosed within 2 weeks of symptom onset and typically has abrupt onset of symptoms

Question 9

what is chronic osteomyelitis

Answer 9

present for many months
typically more of a smoldering presentation and less dramatic
may have flares of pain with periods of patient being asymptomatic

Question 10

what is the most common organism in pediatric osteomyelitis

Answer 10

S. Aureus

Question 11

what is the presentation of osteomyelitis

Answer 11

depends on acute or chronic presentation
fever, redness, swelling, warmth, limited mobility, pain, lymphadenopathy

may be more vague with malaise, fevers/chills, weight loss and discomfort

Question 12

what is important about animal bites

Answer 12

consider potential for direct inoculation at the time of bite or if symptoms of infection persist despite treatment for soft tissue infection

Question 13

what is the most common organism in human bites

Answer 13

S. aureus

Question 14

what is the most common organisms in animal bites

Answer 14

pasteurella multocida

Question 15

how is vertebral osteomyelitis usually spread

Answer 15

hematogenously unless from hardware

Question 16

what is the most common location of vertebral osteomyelitis

Answer 16

lumbar spine
presents with spinal process pain vs muscular pain

Question 17

what is the best test for osteomyelitis

Answer 17

MRI

Question 18

what is septic arthritis

Answer 18

infection within the joint space

Question 19

what is the presentation of septic arthritis

Answer 19

severe joint pain, fever, actuely ill, pain, swelling, effusion

Question 20

what is the most common joint affected in septic arthritis

Answer 20

knee

Question 21

what increases likely risk of septic arthritis

Answer 21

Rheumatoid arthritis

Question 22

what are the most common pathogens in septic arthritis

Answer 22

S. aureous is the most common
pseudomonas aeruginosa in IVDU
Neisseria gonorrheoae in health sexually active adults

Question 23

what is released with inflammation in septic arthritis

Answer 23

PMNs will release proteolytic enzymes which can cause destruction of the joint

Question 24

What is lyme arthritis

Answer 24

tickborn illness that are spead via deer tick due to borrelia burgdorferi

Question 25

when does lyme arthritis present

Answer 25

can occur weeks to years after the initial infection

Question 26

what is borrielia burgdorferi

Answer 26

gram negative spirochete flagella difficult to culture prefer collagen rich tissues

Question 27

what are the stages of lyme disease

Answer 27

early localized, early disseminated, late stage

Question 28

what is the early stage of lyme disease

Answer 28

erythema migrans flulike illness local lymphadenopathy

Question 29

what is the early disseminated stage of lyme disease

Answer 29

skin nervous system: CNS infection, VN palsies Cardiac: transient involvement with AV block, myocarditis Joints: migratory pain, myalgias

Question 30

what is the late stage of lyme disease

Answer 30

marked by lyme arthritis - most commonly involves 1-2 large joints (knee is the most common) can have chronic neurologic damage with memory impairment, irritability, somnolence

Question 31

what are the different types of periprosthetic joint infections

Answer 31

acute and late

Question 32

when do acute periprosthetic joint infections occur

Answer 32

first 3 months after surgery and classified as superficial or deep

Question 33

When do late periprosthetic joint infections occur

Answer 33

one year after surgery typically associated with hematogenous spread

Question 34

what forms with chronic periprosthetic joint infections

Answer 34

biofilm - infection often spread into the bone or interface of bone and implant

Question 35

what is the most common acute periprosthetic joint infection organism

Answer 35

s.aureus usually without biofilm