Ch.41 Osteoporosis

Question 1

What is the osteoporosis according to WHO?

Answer 1

BMD of 2.5 standard deviations below peak bone mass of young healthy adults

Question 2

What is a T score?

Answer 2

Amount of bone density compared to a 35 yo adult of same gender with peak bone mass

Question 3

What is a Z score?

Answer 3

Comparison of bone mass made with same age, sex, race, height and wt

Question 4

What is a normal BMD T score?

Answer 4

T score of -1 or >

Question 5

What is an osteopenic T score?

Answer 5

T score b/w -1 to -2.5

Question 6

What is an osteoporotic T score?

Answer 6

T score of

Question 7

What is severe osteoporosis?

Answer 7

T score of

Question 8

How much bone is replaced annually?

Answer 8

20%

Question 9

What are osteoclasts?

Answer 9

Bone cells that resorb calcified matrix

Question 10

What are osteoblasts?

Answer 10

Bone cells that synthesize new bone matrix

Question 11

Describe the activation phase of bone remodeling

Answer 11

Osteoclastic activity recruited

Question 12

Describe the resorption phase of bone remodeling

Answer 12

Osteoclasts erode bone and form a cavity

Question 13

Describe the Reversal phase of bone remodeling

Answer 13

Osteoblasts are recruited

Question 14

Describe the formation phase of bone remodeling

Answer 14

Osteoblasts replace cavity with new bone

Question 15

Describe the quiescence phase of bone remodeling

Answer 15

Bone tissue remains dormant until the next cycle starts

Question 16

What endocrine disorders can increase rate of bone remodeling?

Answer 16

Thyrotoxicosis

Hyperparathyroidism

Question 17

What is primary osteoporosis?

Answer 17

Rare idopathic juvenile d/o b/w 8-14 yo w/ inc osteoclastic activity for 2-4 years

Question 18

Which hormones inc bone remodeling?

Answer 18

PTH
Thyroxine
GH
Vitamin D

Question 19

Which hormones dec bone remodeling?

Answer 19

Calcitonin
Estrogen
Glucocorticoids

Question 20

What does PTH do in the presence of Vit D?

Answer 20

Stim bone resporption and release of Ca and P

Question 21

What does Calcitrol do?

Answer 21

Produced by kidneys and inc intestinal absorption of Ca and P

Question 22

What does Calcitonin do?

Answer 22

Prohibits Ca and P resorption by inhibiting osteoclastic activity

Question 23

What does active Vit D do?

Answer 23

Inc intestinal absorption of Ca and P

Question 24

How is Vit D synthesized?

Answer 24

Sun exposure and conversion in the liver

Question 25

How does age affect bone remodeling?

Answer 25

Osteoblast activity dec Active form of Vit D-1,25(OH)2 dec ~50% GH dec which stim renal prod of vit D

Question 26

What are the MC locations for osteoporotic fx?

Answer 26

Midthoracic and upper-lumbar spine Proximal femur Distal forearm (Colles fx)

Question 27

What is the risk of death with osteoporotic hip fx?

Answer 27

15% to 20%

Question 28

How does the risk of osteoporotic fx change with every SD of dec in BMD?

Answer 28

1. 5-2.0 fold inc in spine fx | 2. 6 fold inc in hip fx

Question 29

How is a typical limb with hip fx positioned?

Answer 29

Externally rotated and shortened

Question 30

Who is at inc risk of osteoporosis?

Answer 30

``` Estrogen def women Women >65 yo Type I DM Liver dz Kidney dz Thyroid dz FHx of osteoporosis Early menopause Cigarette smokers Alcohol abuse ```

Question 31

What can use of the spinal proprioceptive extension exercise dynamic (SPEED) program do?

Answer 31

``` Dec fall risk and falls at obstacles Dec step width Improve gait steadiness Inc velocity Inc Cadence Inc Stride length ```

Question 32

What is the recommendation for walking to dec osteoporosis risk?

Answer 32

45 min 3x/wk or 30 min daily

Question 33

What exercises should be avoided in osteoporosis?

Answer 33

Spinal flexion

Question 34

What are anti-resoprtive agents?

Answer 34

Estrogens Androgens Calcitonin Bisphosphonates

Question 35

What are osteoblast stimulator agents?

Answer 35

Fluoride (not approved in US d/t risk of appendicular fx) | PTH

Question 36

What is a contraindication of PTH therapy?

Answer 36

Hx of cancer

Question 37

What are the SE of PTH therapy?

Answer 37

``` Nausea Dizziness Leg cramps HA Hypercalcemia ```

Question 38

What is a SE of bisphosphonates?

Answer 38

Osteonecrosis of the jaw

Question 39

What are contraindications of estrogen therapy?

Answer 39

Hx of thromboembolism or thrombophlebitis Suspected breast or endometrial CA Liver or gallbladder dz CV dz

Question 40

What does use of progesterone with estrogen dec risk of?

Answer 40

Endometrial hpyerplasia and CA

Question 41

How should Alendronate be taken?

Answer 41

10 mg/day or 70 mg/wk W/ full glass of water on awakening No eating or reclining for 30-45 min after dose d/t esophageal irritation

Question 42

How should Risedronate be taken?

Answer 42

5 mg/day or 35 mg/wk

Question 43

What doe thiazide diuretics do?

Answer 43

Inhibit urinary excretion of Ca and slow bone loss dec rate of fx