Brainscape's Knowledge GenomeTM

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


See full index

3 > Bone health > Flashcards

Bone health Flashcards

1
Q

Bone distribution

A

cortical 80%

Trabecular 20%

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

Cortical bone function

A

biomechanical strength
attachment site for tendon and muscle
trauma protection

Low turnover rate - Haversian remodelling, periosteal appositional growth

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

Trabecular bone function

A

mineral metabolism
strength
elasticity

higher turnover rate
frequent remodelling

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

Bone matrix composition

A

90% collagen

10% proteins - osteocalcin, osteonectin, osteopontin

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

Bone mineral composition

A

hydroxyapatite - calcium and phosphate

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

bone mass imaging

A

X-ray - not good, need to lose 30% before it is evident
High resolution CT: can do finite element analysis
- allows prediction of force required to break structure

Dual-energy X-ray absorptiometry (DXA) - typically used

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

Fracture epidemilogy

A

bimodal distribution
adolescence - more males, due to trauma to long bones
elderly - more females, mostly low-trauma

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

Fracture risks

A

previous fractures - doesn’t matter which joint
Age

synergistic with bone density

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

DXA

A

low dose radiation

measures amount of calcium in hip/spine

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

BMD

A

relates patient’s bone mass density to normal distribution in population
standard deviations from normal

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

bone formation markers in blood

A

Bone-associated alkaline phosphatase
Collagen type I propeptidases
Osteocalcin

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

bone resorption markers in blood

A

calcium
hydroxyproline
hydroxylysine glycosides
pyridinium crosslinks

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

Bone biopsy

A

rarely used

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

Peak bone mass

A

different sites in the body reach peak at different times

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

WHO definition of osteoporosis

A

more than -2.5 SD below population average

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

WHO classification of osteoporosis for postmenopausal women

A

also used for men >50
stratify based on t scores

Normal >-1.0
Low bone mass/osteopenia -2.5 to -1.0
Osteoporosis <-2.5 with lower fracture

17
Q

FRAX score

A 
determines fracture risk within 10 years
useful for men and women >50, all ethnicities
Other risk factors:
- previous fracture
- parental hip fracture
- current smoking
- GC use
- RA or other secondary causes
- alcohol intake - >3 units/d
18
Q

Osteoporosis scoring in younger men/women

A

Use age-matched Z scores instead of t scores

Use clinical diagnostic features over bone mass

19
Q

Clinical diagnosis of osteoporosis

A

Presence of a fragility fracture

20
Q

Fragility fracture

A

Caused by an injury that would be insufficient to fracture normal bone
Could be due to minimal or no injury

21
Q

Calcium supplementation

A 
1000 mg/day 19-50, 1200 >50
do not prevent fractures
not enough to treat osteoporosis
only need to supplement to sufficiency
CV risk unclear
22
Q

vitamin D supplementation recommendation

A

infants - 400 IU
children/adults - 600
adults > 70 - 800

23
Q

Clinical manifestations of severe vit D deficiency

A

<25 nmol/L
osteomalacia
Ricketts
proximal myopathy, sway, falls

24
Q

Clinical manifestations of moderate vit D insufficiency

A

25-75 nmol/L
secondary hyperparathyroidism
muscle weakness, falls
increase fracture risk
potential for increased risk of cancers, inflammatory arthritis, MS, type I diabetes, TB, influenza
Prevalence of vitamin D deficiency is extremely high in the population

25
Q

Disuse osteoporosis

A

Reduce the stress on bone due to casting, reduced activity –> increased resorption/impaired bone formation

26
Q

Bone scan

A

bone scintigraphy
tracer most commonly used = Tc-99m MDP
MDP becomes incorporated in the mineral phase of bone and visualized via gammacamera
increased tracer uptake with increase in blood flow/osseous remodelling

Causes of increased uptake:

  • tumour (primary/metastatic)
  • infection
  • trauma (mechanical stress)
27
Q

Bone scintigraphy indication

A 
osteomyelitis
stress fractures
occult fractures
metastases
staging for tumours
AVN
28
Q

3-phase bone scans

A

Blood flow phase: arterial bloodflow - e.g. hypervascularity
Blood pool: equilibrium in the extracellular space - soft tissue
Delayed: 2-24 hours after injection of tracer

3 (9 decks)

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