Osteonecrosis & Infection Flashcards

1
Q

What term describes the calcification of normal tissue due to increased serum calcium or phosphorus?

A

Metastatic calcification

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

What term describes the calcification of damaged/diseased tissues in a localized fashion?

A

Dystrophic calcification

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

What term describes the intramembranous bone formed in response to stress on bone or soft tissue?

A

Reactive bone formation (periosteal reaction)

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

Name 4 types of periosteal reaction

A

solid
laminated
spiculated
Codman’s triangle

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

What occurs in a solid periosteal reaction?

A
  • slow growing, non-aggressive
  • as periosteum is lifted slowly, it fills in completely
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What occurs in a laminated periosteal reaction?

A
  • aggressive process
  • lifts periosteum, stops, lifts again, etc., (allows layering/onion effect)
  • lays down bone during rest phase
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What occurs in a spiculated periosteal reaction?

A
  • aggressive process
  • periosteum lifted rapidly
  • bone growth along Sharpey fibers creates hair-on-end (parallel) or sunburst (outward) appearance
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What occurs in a Codman’s triangle periosteal reaction?

A
  • aggressive pattern
  • strips periosteum away from adjacent uninvolved bone
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What term describes the death of bone and bone marrow in the absence of infection?

A

Osteonecrosis

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

What is the most common cause of osteonecrosis?

A

Infarction (loss of blood supply)

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

Osteonecrosis of the epiphyseal region is called ____

A

avascular necrosis (AVN)

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

Osteonecrosis in the metaphyseal/diaphyseal region is called ____

A

bone infarct

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

The inflammation of bone due to a bacterial infection is called?

A

Osteomyelitis

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

What is the most common etiology of osteomyelitis?

A

Staphylococcus aureus

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

What are the 3 routes of spread for osteomyelitis? Which is most common?

A
  1. Hematogenous spread (MC)
  2. Lymphatic
  3. Contiguous (direct/implantation)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

In the case of hematogenous osteomyelitis, bacteria spread from inside the bone to the subperiosteal space using the ____ and ____ canal systems

A

Haversian
Volkmann’s

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

What factors play a role in the severity of a bacterial infection?

A
  1. Virulence of the bacteria
  2. Pre-existing health complications
  3. Patient’s age
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is the most common form of osteomyelitis that comes from skin pustules or infected teeth or gums?

A

Hematogenous osteomyelitis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What areas does osteomyelitis most commonly affect?

A
  • metaphyseal regions (most metabolically active)
  • lower extremity and hands (blood pooling)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

When using the term “osteomyelitis” on its own, the implication is…

A

acute pyogenic osteomyelitis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What pattern of necrosis is found in tissues undergoing osteomyelitis?

A

Liquefactive necrosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What type of edema is produced by the tissue necrosis in osteomyelitis?

A

Purulent exudate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Describe the pathogenesis of osteomyelitis

A
  • bacteria escape vasculature & proliferate -> local necrosis
  • edema results in ^medullary pressure
  • ^osteoclast activity in infected area
  • necrotic debris lifts periosteum -> reactive bone formation
  • periostitis -> loss of blood supply -> necrosis of cortical bone
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What term describes an inflammation of the periosteum?

A

Periostitis

25
Q

During a bacterial infection, increased edema fluid may put pressure on surrounding capillaries and result in what?

A

Osteolysis

26
Q

How long does it take for osteomyelitis to appear on x-ray in the extremities versus the spine?

A
  • extremities: 7-10 days
  • spine: 21 days
27
Q

On a radiograph, what is the area of reactive bone formation when them periosteum is lifted called?

A

Codman’s Triangle

28
Q

What is a cloaca?

A

an opening in the cortex of bone that allows bacteria to spread to other tissues

29
Q

What is a sequestrum?

A

a piece of necrotic bone tissue

30
Q

What is an involucrum?

A

an area of reactive bone formation that forms a sheath around a sequestrum

31
Q

What is a sinus?

A

where pus drains from bone into the outside environment

32
Q

What are some of the cardinal signs of an acute pyogenic osteomyelitis infection?

A
  • Rapid onset, high fever
  • Severe throbbing pain that worsens rapidly
  • Swelling and redness
  • Sharp cortical line may be lost
33
Q

How is chronic osteomyelitis characterized?

A
  • reactive bone formation -> enlargement, involucrum, sequestrum
  • cloaca & possibly sinus
  • multiple lytic lesions (porous appearance)
  • can destroy multiple bones and tissues over time
34
Q

What are some of the possible radiographic characteristics seen with osteomyelitis?

A
  • Lytic areas in cortex and medullary cavity
  • Decreased disc space and loss of vertebral endplates
  • Decreases vertebral height due to pathologic fracture
35
Q

What are some of possible radiographic characteristics seen with vertebral osteomyelitis?

A
  • decreased/obliterated disc space
  • loss of vertebral endplates
  • pathological fracture if vertebra
  • Favors thoraco-lumbar region, but can be anywhere
  • in kids: disc -> vertebrae
  • adults: vertebrae -> disc
36
Q

If multiple bones and tissues are involved, ____ MUST be on your DDX until proven otherwise

A

infection

37
Q

What are some of the possible laboratory findings that can help diagnose vertebral osteomyelitis?`

A
  • Leukocytosis
  • Elevated ESR and C-reactive protein
38
Q

What are the possible clinical characteristics of osteomyelitis?

A
  • possible cardinal signs
  • pathological fracture
  • bone enlargement over time
  • squamous cell carcinoma (Marjolin Ulcer) along draining sinus or cloaca
  • bone sarcoma
39
Q

What are the risk factors for spondylodiscitis/vertebral osteomyelitis?

A
  • hematogenous spread from other sites
  • intravenous drug use
  • upper urinary tract infections
  • urological procedures
  • diskitis
40
Q

What is a Brodie’s Abscess?

A
  • subacute metaphysical infection of bone
  • reactive bone that surrounds & contains infection
41
Q

A Brodie’s abscess may result in ____ of the lesion

A

sterilization

42
Q

What Hematogenous route does tuberculosis infections utilize to spread to bone? Why?

A
  • Batson’s venous plexus
  • basivertebral vv don’t have valves -> blood can flow backwards)
43
Q

What pattern of inflammation is associated with tuberculosis infections?

A

Chronic inflammation

44
Q

What morphological pattern of inflammation is associated with tuberculosis infections?

A

Granulomatous inflammation

45
Q

What pattern of necrosis is associated with tuberculosis infections?

A

Caseous necrosis

46
Q

What parts of the spine are affected by a tuberculosis infection?

A

destruction of vertebral body with sparing of discs

47
Q

What parts of the spine are affected by vertebral osteomyelitis?

A

destruction of vertebral body and discs

48
Q

If tuberculosis infection ruptures into soft tissue, this can cause ____

A

Cold abscesses

49
Q

What are cold abscesses and how do they appear on x-ray?

A
  • abscesses lacking acute inflammation (subligamentous extension = skip lesions)
  • snowflake sign: white dots along psoas muscle
50
Q

What term describes a sharply angled kyphosis in the thoracic spine often seen in Tuberculosis infections?

A

Gibbous deformity
(vertebral collapse and destruction of vertebral bodies)

51
Q

What are the clinical manifestations of Tuberculosis?

A
  • insidious onset (mild -> severe), stiffness
  • focal tenderness, decreased ROM in spine
  • spinal pain w/ or w/out neuro involvement
  • cold (psoas) abscesses
  • Gibbous deformity
  • paraplegia from vascular insufficiency of spinal nn
52
Q

A patient walks into your clinic complaint of pain and stiffness in the spine. They have decreased ROM and notice a hyperkyphosis of the spine as they walk in. What is a possible condition you suspect is wrong with the patient?

A

Tuberculosis infection

53
Q

What is the etiology of Syphilis?

A

Treponema pallidum

54
Q

What are some of the clinical manifestations of an acquired syphilis infection?

A
  • Saddle nose
  • Sabre shin
  • Gummas
  • bone erosion
  • neurological symptoms
55
Q

What term descirbes a granulomatous lesion with a central area of coagulative necrosis, epithelioid macrophages, and giant cells surrounded by fibrous tissue?

A

Gummas

56
Q

What condition is the sign Sabre shin most commonly associated with?

A

Syphilis

57
Q

What prominent signs are specific to congenital syphilis infection?

A
  • Hutchinson’s teeth
  • neurological symptoms -> milestone delays
58
Q

What is the result of a dislocated epiphysis caused by a treponema pallidum growth plate infection that leads to a functionless limb?

A

Pseudoparalysis of Parrot