Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Block 7 Week 5 > Bone and Joint Infections > Flashcards

Bone and Joint Infections Flashcards

1
Q

If you expect osteomyelitis, what tests should you order?

A

x-ray
CBC
blood culture
sedimentation rate/CRP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What does a sedimentation rate measure?

A

inflammation!

TMI: Sed rate, or erythrocyte sedimentation rate (ESR), is a blood test that can reveal inflammatory activity in your body.

When your blood is placed in a tall, thin tube, red blood cells gradually settle to the bottom. Inflammation can cause the cells to clump together. Because these clumps of cells are denser than individual cells, they settle to the bottom more quickly.

The sed rate test measures the distance red blood cells fall in a test tube in one hour. The farther the red blood cells have descended, the greater the inflammatory response of your immune system.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What tests are good early on for osteomyelitis?

A

bone scan

MRI

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What’s the most likely organism causing osteomyelitis?

A

S. Aureus

maybe Strep

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Do you need to perform a needle biopsy for osteomyelitis?

A

no

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

How to treat osteomyelitis?

A

oral antibiotics

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What organism is most likely to cause a pathologic fracture?

A

S. Aureus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

If you suspect a pathologic fracture, what specimens should you send to the lab? What culture would NOT be helpful?

A

send a bone culture; do not use a sinus tract culture, usu not helpful unless you can isolate a single organism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the gold standard for determining the cause diagnosis of a fracture?

A

open bone biopsy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

T/F: Sinus tract cultures are a great tool for determining the cause of a bone infection.

A

No, sinus tract cultures correlate poorly with bone cultures; don’t trust sinus cultures unless the results yield a single organism or S. aureus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

If there is “hardware” in the leg prior to a break and subsequent infection, what should be done?

A

hardware removal, antibiotics, new hardware later

**might be OK if you don’t remove the hardware if the infection is detected early

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is a good antibiotic to put a patient on while waiting for results of a culture for bone infection?

A

vancomycin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

So, prosthetic devices like those inserted in a hip replacement can become infected with MRSA and enterococcus. What should be done in this case?

A

2 stage replacement w 2-6 weeks b/w surgeries

give antibiotics

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Under what circumstances can a prosthesis be retained after debridement?

A

symptoms <3weeks
stable implant
easy to treat organism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

When would it be OK to use single stage replacement for a prosthetic infection?

A

symptoms <3weeks
soft tissue in good shape
no co-morbidities
easy to treat organism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

If an IV drug user comes in with infection, what bugs do you expect? What imaging study might be helpful? What drugs would you prescribe?

A

staph > strep > Gram negative bacteria > fungi;
MRI;
nafcillin + gentamycin or
vancomycin + gentamycin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Why might a patient with a vertebral osteomyelitis complain of mid-thoracic radicular pain?

A

spinal ache - first sign of epidural abscess

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

When might you use debridement for vertebral osteomyelitis?

A 
instability
abcess
cord compression
cervical infection
neuro signs and symptoms
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

For vertebral osteomyelitis, what antibiotics would you use and for how long?

A

quinolones for 4 weeks or longer if hardware in place or abscesses not drained

20
Q

Why might it be bad to order an MRI while a spinal osteomyelitis is healing?

A

MRI less than 4 weeks into Rx often look worse even in patients improving – don’t order! Follow clinically.
MRI later – don’t follow bone changes – often progress. Focus on epidural and soft tissue changes – if these are equivocal or progress suggests failure

21
Q

Gold standard for osteomyelitis?

A

histopathologic evidence with supporting microbial data

**usu the diagnosis rests on clinical, laboratory, and radiographic date

22
Q

In diabetic foot infections, what are some exam findings that predict bone involvement?

A

larger (>2cm) and deeper suggest osteomyelitis
ESR >70
probe to bone

23
Q

What are the best imaging modalities for diabetic foot infections?

A

plain film
CT
MRI
nuclear medicine studies

24
Q

When are plain films useful? Why are they not helpful in cases of acute osteomyelitis?

A

in chronic infection, like sclerosis or periosteal elevation and sequesta; you need like 30-50% mineral loss for anything to be notable of x-ray

25
Q

Best method for detecting small areas of necrosis, gas, foreign bodies; metallic foreign bodies compromise the image

A

CT

26
Q

Best single test for diabetic foot infections; great sensitivity

A

MRI

27
Q

Will be positive on bone scan immediately and in 15 minute phase

A

soft tissue infection

28
Q

Will be positive on bone scan immediately, 15 minute phase, and in delayed (>4hour) images

A

osteomyelitis

29
Q

What organisms are likely involved in diabetic foot ulcers that are chronically infected or necrotic and malodorous?

A

S. aureus, B strep, enterococci, enterobacteriaceae, pseudomonas species
other anaerobic species

30
Q

How to treat nasty diabetic foot and bone ulcers?

A

surgical debridement
re-vascularization if needed
long-term antibiotics

**AB alone probably insufficient

31
Q

What antibiotics should you use for diabetic foot infections?

A
  1. always cover gram +, esp staph
  2. add gram - coverage for chronic wounds or if pt previously treated with anbx for moderate/severe wounds
  3. anaerobic coverage if necrotic wound or feculent odor
32
Q

Is anbx coverage for enterococci and pseudomonas usually necessary in diabetic foot infections?

A

not usually; if enterococci is the only organism, OK; if pseudomonas is present and the pt is not improving, OK

33
Q

Duration of anbx therapy for diabetic foot infections?

A

4-6 weeks or longer

34
Q

MRI of his spine reveals complete destruction of T6, a 20 anterior acute angle deformity and a large para-spinal fluid collection. Biopsy reveals granulomas, no AFB. What is going on??

A

TB - patient needs anti-TB therapy and surgery

35
Q

Responsible for 1/3 of cases of skeletal TB.
Infection begins in the anterior aspect of the vertebral body leading to anterior collapse and spread of the infection along the anterior ligament
Most cases involve the lumber and lower thoracic spine
50% of cases have associated abscesses (if calcified is diagnostic for TB)

A

Pott’s disease

36
Q

Indications for surgery in Pott’s disease?

A

neuro deficits
instability
cervical spine disease
medical therapy failure

37
Q

In developed countries (blank) is a disease of adults and represents reactivation of an old focus of infection.
In the developing world most cases occur in patients who recently acquired TB. Therefore, most cases occur in childhood. Many patients give a history of recent trauma to the involved area.

A

skeletal tuberculosis

38
Q

Accounts for 35% of cases of extra-pulmonary TB and 2% of all cases of TB
Indolent course, average duration of symptoms prior to diagnosis: 16 to 19 months.
Local swelling, pain, fluctuance; systemic symptoms (fever, sweats, etc) often absent.
Pulmonary disease present in 30%. PPD+ in > 85%

A

skeletal TB

39
Q

How can you differentiate infected vs non-infected joint fluid?

A

aspiration –> gram stain –> culture

40
Q

In 80% of cases of RA, what bug can cause infection of joints? Does the joint need to be drained?

A

S. aureus; serial aspiration or open procedure

41
Q

A 23 year old female reports to the ER with 2 days of diffuse arthralgias, low grade fever and then the development of swelling and increased pain in her right knee and wrist. She has a new boyfriend. Diagnosis?

A

gonorrhea

42
Q

What are some risks for gonorrhea infection?

A

female
menstruating
complement deficinecy

43
Q

Gout has (blank) birifringent crystals, while pseudogout has (blank) birifringent crystals

A

negative; positive

44
Q

When would glucose be low in a synovial fluid analysis?

A

inflammatory arthritis

septic arthritis

45
Q

Should joints be drained if gonorrhea suspected?

A

yes

46
Q

What anbx should ya give for gonorrhea?

A

ceftriazone for 7-10 days

**treat partner, too

Block 7 Week 5 (8 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions