Brainscape's Knowledge GenomeTM

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


See full index

Locomotor 2 > Ageing and Metabolic Bone Conditions > Flashcards

Ageing and Metabolic Bone Conditions Flashcards

1
Q

what does osteoporosis serum results look like

  • calcium
  • phosphate
  • alkaline phosphatase
  • PTH
  • 1,25(OH)2 Vitamin D
A
  • calcium = normal
  • phosphate = normal
  • alkaline phosphatase= normal
  • PTH = normal
  • 1,25(OH)2 Vitamin D = normal
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What does osteomalacia serum results look like

  • calcium
  • phosphate
  • alkaline phosphatase
  • PTH
  • 1,25(OH)2 Vitamin D
A
  • calcium = decrease
  • phosphate = decrease
  • alkaline phosphatase = increase
  • PTH = increase
  • 1,25(OH)2 Vitamin D = decrease
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What does paget’s serum results look like

  • calcium
  • phosphate
  • alkaline phosphatase
  • PTH
  • 1,25(OH)2 Vitamin D
A
  • calcium = normal
  • phosphate = normal
  • alkaline phosphatase = double increase
  • PTH = normal
  • 1,25(OH)2 Vitamin D = normal
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What does renal failure results look like

  • calcium
  • phosphate
  • alkaline phosphatase
  • PTH
  • 1,25(OH)2 Vitamin D
A
  • calcium = decrease
  • phosphate = increase
  • alkaline phosphatase = normal and increase
  • PTH = increase
  • 1,25(OH)2 Vitamin D = decrease
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What does primary hyperparathyroidism look like

  • calcium
  • phosphate
  • alkaline phosphatase
  • PTH
  • 1,25(OH)2 Vitamin D
A
  • calcium = increase
  • phosphate = decrease
  • alkaline phosphatase = normal and increase
  • PTH = increase
  • 1,25(OH)2 Vitamin D = normal
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what produces alkaline phosphatase

A

= produced by osteoblasts and liver

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

decrease what happens to the bone in osteoporosis

A
  • the ratio between unmineralised and mineralised bone remains the same
  • more bone is reabsorbed and less bone is made therefore there is less bone
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

describe what happens to the bone in osteomalacia

A
  • increase in the amount of unmineralised matrix
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

describe what happens to the bone in a mixture of osteoporosis and osteomalacia

A
  • have less overall amount of bone and more unmineralised bone
  • common to have a co-mordbity of them
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

who is osteoporosis more prevalent in

A

women

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

what age do both men and women lose bone mass from

A
  • both lose bone mass from age 40 onwards

- 0.7% a year

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

when does women bone loss speeds up

A

In women bone loss speeds up after menopause

2-9% a year

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

how do you measure bone mineral density

A

T or Z score from the DEXA scan

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

What is the T score

A

number of standard deviations from the mean young (30 yr) same gender and ethnicity

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

What is the Z score

A

number of standard deviations from mean aged, same gender and ethnicity

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

why do women get osteoporosis after menopause

A
  • loose oestrogen which is protective

- oestrogen inhibits osteoclasts and increases the amount of calcium that is absorbed across the gut

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

what does DEXA scan stand for

A

dual energy X ray absorptiometry

- results show as a T and Z score

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

What are DEXA scans used for

A
  • to look a bone mineral density

- when you have a fracture from a low force

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

what are the T scores of osteopenia between

A

1 and -2.4

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

what are the T scores for osteoporosis

A

Osteoporosis T scores below -2.5

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

what is the prevalence of osteoporosis in 50 and 80 years old

A

2% at 50 years

Greater than 25% at 80 years

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

what does osteoporotic bone looks like

A
  • Bones with a high proportion of trabecular bone more susceptible to osteoporotic bone loss
  • bigger gaps between
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What two bones are commonly affected by osteoporosis

A
  • vertebral bodies

- femoral neck

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

what is a compression fracture

A
  • this is when there is a completely collapsed vertebrae body
  • due to the weight of the body causing the thin network of fine trabecular to collapse and break
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

what is the underlying cause of osteoporosis

A

Relative increase in resorption not matched by formation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

In osteoporosis what bone is particularly at risk to loss

A

Trabecular bone

  • greater surface area (10x more surface area)
  • this type of bone is in locations that has to respond to new stresses
  • once you have thin trabecular you haven’t got the osteoblasts lined up to replace the damaged bone
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What does osteoporotic bone look like

A
  • Cortices and trabecular is thinned

- Osteoid seams are normal (approximately 20% of unmineralised osteoid)

28
Q

what part of the vertebrae is particularly affected by compression fractures

A

cervical

29
Q

how many people does compression fractures of the vertebrae affect

A

2 million postmenopausal women in England and Wales

180,000 fractures a year

30
Q

describe the osteoporosis treatment pathway

A
  • if they are over 75 and have a low trauma fracture then start the patient on bisphosphonate, calcium and vitamin d
  • if they are between the age of 50-75 and have had a low trauma fracture refer for a dexa scan

Dexa scan results

  • aged 50-65, and the T score is less than -3.2 then start on bisphosphonate, calcium and vitamin D
  • if aged 50-65 and the T score is between -2.5 and -3.2 and there is a clinical risk factor then start on bisphosphonate, calcium and vitamin d
  • if aged 50-75, and the T score is greater than -2.5, start on calcium and vitamin D
  • if age 65-75, and T score is less than -2.5 then start on bisphosphonate, calcium and vitamin D
31
Q

list some treatments that you can use to treat osteoporosis

A
  • calcium supplements in order to reduce negative calcium balance
  • vitamin D
  • HRT - oestrogen replacement in perimenopausal women - lasts for 5 years
  • selective oestrogen receptor modulator (raloxifene)
  • Bisphophonates
  • Teriparatide - rPTH
  • denosumab - monoclonal antibody binds to RANKL
32
Q

How does raloxifene work

A
  • Selective oestrogen receptor modulator that has estrogenic actions on bones and anti-estrogenic actions on the uterus and breast
  • prevents osteoporosis in post menopausal women
  • not recommended as a primary treatment to prevent OP
33
Q

How does bisphophonates work

A
  • inhibit bone reabsorption
  • they inhibit osteoclast activity and promote osteoclast apoptosis
  • increases OPG production
  • decreased RANKL expression
34
Q

By how much does bisphophonates reduce fracture risk by

A
  • reduces fracture risk by 50%
35
Q

What are the complications of bisphosphonates

A
  • Giant osteoclasts
  • osteonecrosis of the jaw - dead bone is not removed and replaced with new bone

Atypical fractures

  • subtrochanteric and femoral shaft
  • old osteocytes signal for remodelling but fewer good osteoclasts
36
Q

how does teriparatide work

A

Intermittent exposure to PTH will activate osteoblasts more than osteoclasts therefore causing more bone production then reabsorption

37
Q

How does denosumab work

A

FDA approval June 2010, NICE October 2010

Subcutaneous injection every 6 months

binds to RANKL and inhibits it therefore Inhibits formation of osteoclasts

38
Q

What is osteomalacia due to

A

Usually result of vitamin D deficiency either in diet or production

39
Q

what happens in osteomalacia

A
  • insufficient calcium and phosphate to mineralise new bone osteoid
40
Q

who is osteomalacia more deforming in and why

A

In children the epiphyseal growth plate still open
= more deforming

In adults epiphyseal growth plate closed
= less deforming

41
Q

what are the lab results for osteomalacia

A

Low serum calcium and phosphorus

High alkaline phosphatase

42
Q

what is osteomalacia called in childhood

A

rickets

43
Q

what is a sign of rickets and why does this occur

A
  • bowed legs

- children have open epiphyseal growth plates, these widen and spread out

44
Q

what are pseudo fractures

A
  • these look like fractures but they are not
  • they can progress to insufficiency fractures
  • areas of unmineralised bone
  • form at areas of higher bone turnover
45
Q

what is the percentage of normal unmineralised osteoid

A

Normal bone unmineralised osteoid is around <20%

46
Q

describe what osteomalacia looks like

A
  • wide seems of unmineralised osteoid
  • in severe cases up to 100% of bone is covered by unmineralised osteoid
  • active osteoclasts increased
47
Q

describe unmineralised osteoid

A

Must be greater than 80% of the total bone surface covered by osteoid

Osteoid thickness must be greater than 14μm

48
Q

What happens in osteomalacia

A
  • low bone turnover state
49
Q

What does tetracycline look like in osteomalacia

A

Some areas have no tetracycline labelling

Some areas diffuse labelling suggestive of the altered mineralization

Some have a single line

50
Q

What are the treatments of osteomalacia

A
  • Vitamin D supplements - may need to take these for the rest of your life if you have liver or kidney failure
  • increase calcium
  • sun and UV exposure
51
Q

what foods have calcium in them

A 
Milk
bread
beans and pulses
dried fruit
 green leafy vegetables!
52
Q

how much sun or UV exposure should you have

A

15 mins of sun on hands and face 2-3 times a week in spring and summer is sufficient

53
Q

What is the prevalence of Paget’s disease

A

Rare <40 years

3% of population >50 years

10% of population >80 years

54
Q

How many phases of Paget’s disease are there

A

3

55
Q

What are the three phases of Paget’s disease

A

phase 1

  • initial increase rate of bone reabsorption and there is a large number of giant osteoclasts
  • they remove a lot of bone this leads to osteoblast becoming more active

phase 2

  • compensatory phase/proliferative
  • increase bone formation
  • acclearated deposition in disorganised manner
  • lots of woven bone being laid down

phase 3

  • burnout phase/sclerotic
  • bone hypercellularity may diminish leaving paretic bone
  • hypervascular bone marrow
56
Q

what does Paget’s disease look like

A

Irregular thickened trabeculae

Prominent cement lines

Bone marrow replaced by fibrovascular connective tissue

trabecular is filled in so looks like cement

57
Q

what does Paget’s disease look like physically

A
  • bells palsy

- causes hearing problems

58
Q

what are bones are commonly affected in Paget’s disease

A 
pelvis
	femur
	vertebrae
	skull
	tibia
59
Q

what is a rare complication of Paget’s disease

A

Osteosarcoma - 1% of cases

60
Q

who does osteosarcoma usually occur in

A

the young

61
Q

describe osteosarcoma

A
  • among the most malignant of cancers
  • usually in the long bone and often near the knee
  • spread rapidly to the lungs
62
Q

How do you prevent spread of osteosarcoma

A
  • removal of part of the affected bone

- limb amputation

63
Q

How do you treat Paget’s disease

A

bisphosphonates
- works directly on osteoclasts to slow bone reabsorption

  • oral 2-6 months
  • IV single infusion to 3 infusions
  • calcium and vitamin D supplements
  • pain surgery
  • surgery
  • calcitonin used less than bisphopshonates
64
Q

what is scerltosis (van buchen syndrome)

A

Associated with absence or reduced production of sclerostin

65
Q

what does sclerotin do

A

Secreted by healthy osteocytes

Normally inhibits osteoblasts to prevent excessive bone formation

66
Q

Describe what sclerostosis do

A

Autosomal recessive

Endosteal hyperostosis

Resistance to fracture

Excessive height

67
Q

what could blocking sclerotin do

A

used for osteoporosis

Locomotor 2 (30 decks)

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