Brainscape's Knowledge GenomeTM

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


See full index

MSK > Osteomyelitis > Flashcards

Osteomyelitis Flashcards

1
Q

What type of bone is most likely to get infected in adults?

A

Cancellous (spongy) bone

Any bone can be affected

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

Where is the most common site for osteomyelitis in children?

A

Distal femur and proximal tibia

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

Through what structures can infection spread from spongy bone to compact bone?

A

Via haversian canals

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

How is osteomyelitis classified?

A

Haematogenous

Contiguous (direct)

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

How does haematogenous osteomyelitis arise?

A

Bacteria spread to the bone via bloodstream from a distant source e.g. Infected urinary catheter

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

How does direct osteomyelitis arise?

A

Direct contact of infected tissue with bone e.g. Trauma, orthopaedic surgery

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

Define chronic osteomyelitis

A

Infection for >6 month

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

Briefly outline the pathophysiology of osteomyelitis

A

Local infection lead to:
Cortex erosions, leading to cloacae
Exudation of pus, causing separation of the periosteum from the underlying cortical bone, leading to sequestra and involcrum formation

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

What are cloacae?

A

Holes in the cortex due to erosion by the infection

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

What are sequestra and how to they form?

A

Necrotic fragments of bone

Forms due to loss of blood supply to the area of bone as the periosteum is lifted away due to pus exudation

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

What is an involcrum and how does it form?

A

Area of new bone formation

New bone is laid down when the periosteum is lifted

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

What does the presence of sequestra indicate?

A

Chronic osteomyelitis

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

What are the risk factors for osteomyelitis?

A 
Diabetes
Peripheral vascular disease
Immunosuppression e.g. HIV, long term steroid use
Sickle cell disease
Surgical prosthesis
Open fractures
Orthopaedic surgery
IVDU
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the most common organism that causes osteomyelitis?

A

Staph. aureus

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

How does acute osteomyelitis typically present?

A 
Pain
Tenderness
Warmth
Erythema
Immobile limb
Systemic symptoms - fever, malaise
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Briefly describe some atypical presentations of osteomyelitis

A

Mild symptoms with history of blunt trauma to the area e.g. bumping shin on hard surface

Non specific malaise

Vertebral infection - chronic back pain

17
Q

What investigations would you do if you suspected osteomyelitis?

A

Bloods: FBC, ESR/CRP, cultures
X-ray
MRI

18
Q

For acute osteomyelitis, would you do MRI or X-ray, and why?

A

MRI
Shows soft tissue changes better
more sensitive in acute infections because X-ray changes can take up to 14 days to become apparent

19
Q

What would you see on X-ray in a) acute and b) chronic osteomyelitis?

A

A) Haziness
Loss of bone density
Subperiosteal reaction

B) sequestra
Involcrum (deformed bone)

20
Q

Roughly what percentage of blood cultures come back positive?

A

60%

21
Q

What is the gold standard investigation for diagnosing osteomyelitis?

A

Bone biopsy and culture

Not usually required in acute cases

22
Q

How would you manage osteomyelitis?

A 
Drain any abscesses
Open surgery to remove sequestra (send for mc&s)
Empirical antibiotics
Analgesia
Limb splinting
23
Q

Which antibiotics would you give empirically?

A

Flucloxacillin + ciprofloxacin

If pen allergic: clindamycin + ciprofloxacin
If MRSA: vancomycin + ciprofloxacin

24
Q

How long should the antibiotic therapy last in a) acute and b) chronic cases?

A

A) 4-6 weeks

B) 12 weeks

25
Q

How would you treat chronic osteomyelitis?

A

Delay antibiotics until culture and sensitivities are back UNLESS the pt is very unwell, in which case start empirical therapy
Surgical debridement

26
Q

What must you be aware of in diabetic patients with foot ulcers?

A

Peripheral neuropathy means they may not feel pain in their foot so osteomyelitis may be missed

27
Q

What particular complication are diabetics more at risk of?

A

Amputation

28
Q

What are the complications of osteomyelitis?

A 
Progression to chronic osteomyelitis, leading to deformity
Abcess formation
Sinus formation (due to abcess rupture)
Septicaemia
Fractures
Septic arthritis
Nonunion of fractures
Loosening of prosthesis
29
Q

What is the staging system for osteomyelitis and what factors does it consider?

A

Cierny-Mader staging

Anatomical state of bone
General condition of the patient
Factors affecting immunity, metabolism and local vascularity

MSK (6 decks)

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