Brainscape's Knowledge GenomeTM

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


See full index

Y2 MSK > MSK infections > Flashcards

MSK infections Flashcards

1
Q

what are streptococcus coagulase -ve beta haemolytic

A
  • Group A strep (throat, skin infections)
  • Group B strep (neonatal meningitis)
  • Group C, G etc
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what are streptococcus catalase -ve, gamma-haemolytic (non haemolytic)

A
  • enterococcus (gut commensals, UTI)
  • e.faecalis
  • e.faecium
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what are streptococcus catalase -ve alpha haemolytic

A
  • strep pneumoniae (pneumonia)

- strep viridins ( commensals, endocarditis)

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

what are staphylococcus coagulase +ve

A

staph.aureus (wound, skin infections)

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

what are staphylococcus coagulates negative

A

staph.epidermidis

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

what is the only coagulase positive staph

A

s.aureus

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

what enzyme does staph aureus produce

A

produces enzymes including coagulase, an enzyme that clots plasma. This distinguishes it from other staph species

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

what antibiotics are active in staph aureus

A 
Flucloxacillin 
Cefazoline 
Vancomycin 
Teicoplanin 
Daptomycin
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what is osteomyelitis

A

Osteomyelitis is an infection that usually causes pain in the long bones in the legs.

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

what is the pathogenesis of osteomyelitis

A
  • Blood flow slowed and turbulent predisposing to bacterial seeding
  • Area is a catch basin for bacteria and abscess may form
  • Abscess spreads transversely along Volkmann canals and elevates periosteum
  • Segment of devitalised bone remains within it.
  • Occasionally abscess is walled off by fibrosis and bone sclerosis to form Brodie abscess
  • Infectious process may erode periosteum and form sinus through soft tissues and skin to drain externally
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what is the route of bacteria of osteomyelitis

A

HEMATOGENOUS - through blood. Monobacterial

  • Children = long bones
  • Adults = vertebrae

CONTIGUOUS - polimicrobial

  • Young = injuries and surgery
  • Elderly = pressure sore, vascular insufficiency
  • DM = soft tissue infections, neuropathy, vascular insufficiency
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what is the bacteria that causes osteomyelitis in children, adults and elderly

A 
children = s.aureus, Group B strep 
adults = staphylococcus aureus 
elderly = frequency of gram negative bacteria increased
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what are the principles of diagnoses for osteomyelitis

A

SUSPECT

  • Patient medical history and epidemiology
  • Examination (probe to bone/visible bone, non healing ulcer, sinus)

SAMPLE (gold standard is a biopsy)

  • wound swabs/blood cultures not always diagnostic
  • histology

TREAT (await microbial diagnoses)
- unless sepsis

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

when is the only time you should do antimicrobials before culturing

A

sepsis or soft tissue infection

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

what ways can osteomyelitis come about

A
  • open fractures
  • diabetes/ vascular insufficiency/ neuropathy
  • haemoatogeneous osteomyelitis
  • vertebral osteomyelitis
  • specific hosts and pathogens
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

how can osteomyelitis come about from open fractures

A
  • Contiguous infection/ direct spread
  • Polymicrobial
  • Early management is key (aggressive debridement, fixation and soft tissue cover)
  • Clinical cue: non-union and poor wound healing
  • Staphylococcus aureus and aerobic gram negative bacteria
17
Q

how can osteomyelitis come about in diabetes/venous insufficiency

A
  • contiguous infection
  • polymicrobial
  • investigations: probe to bone, plain radiograph, MRI
  • treatment: debridement and antimicrobials
18
Q

what would be the treatment taken for a antibiotic nave (no previous antibiotics for DFU in previous month) patient with diabetic foot ulcer osteomyelitis

A

6 weeks therapy initially
For acute presentation usually 2 weeks of IV therapy initially

ACUTE

  • flucloxacillin 2g qds (IV)
  • consider additional gram negative and anaerobic cover as per severe regime if patient not improving

CHRONIC
- avoid empirical treatment and use pathogen directed therapy from biopsy results

19
Q

what would be the treatment for a non antibiotic naive patient with osteomyelitis diabetic foot ulcer

A

ACUTE:

  • Vancomycin (IV) aim for prepose level 15-20mg/l
  • consider additional gram negative anaerobic cover as per severe regime if patient not improving

CHRONIC

  • avoid empirical treatment and use pathogen directed therapy from biopsy results
  • if empirical treatment requires to be initiated recommend doxycycline 100mg bd (oral) +/- metronidazole 400mg tds (oral)
20
Q

what antimicrobial is used for gram positive cover

A
  • flucloxacillin (IV) for staph
  • vancomycin instead of flucloxacillin for penicillin allergy
  • oral switch for gram positive is doxycycline (bone penetration excellent)
21
Q

what antimicrobial is used for gram negative over

A
  • Gentamicin/Aztreonam IV if severe

- Oral cotrimoxazole/doxycycline if suitable for oral treatments

22
Q

who is at risk for getting haematogeneous osteomyelitis

A 
Prepubertal children 
People who inject drugs 
Central lines/dialysis 
Elderly 
Special conditions (ie sickle cell)
23
Q

what is Gauchers disease

A

rare genetic disorder passed down from parents to children (inherited). When you have Gaucher disease, you are missing an enzyme that breaks down fatty substances called lipid

24
Q

what are features of vertebral osteomyelitis

A
  • mostly haematogenous

- may be associated with: epidural abscess, psoas abscess

25
Q

what are clinical features of vertebral osteomyelitis

A
  • fever
  • insidious pain and tenderness
  • neurological signs/symptoms
  • raised inflammatory markers
  • raised white cell count
26
Q

how do you treat vertebral osteomyelitis

A
  • drainage of large paravertebral/epidural abscess
  • antimicrobials for 6 weeks minimum
  • Expect 50% decrease in ESR/CRP
  • duration extended in complicated cases
  • MRI repeated only if unexplained increase in inflammatory markers, increasing pain, new anatomically related signs/symptoms

Y2 MSK (13 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions