The case of the Crumbling Spine

Question 1

Fragility fracture?

Answer 1

Fragility fracture

fracture caused by fall from standing height or less or spontaneous

Question 2

Causes of Fragility Fractures (4)

Answer 2

reduced bone mineral density
altered bone architecture
changed bone material properties
treatment non-adherence

Question 3

how do we measure bone mineral density?

Answer 3

how do we measure bone mineral density?
bone densitometry (DEXA)

Question 4

how do we evaluate bone architecture?

Answer 4

how do we evaluate bone architecture?
trabecular bone score
high res peripheral CT

Question 5

what bone materials can change causing fragility fractures?

Answer 5

type 1 collagen

hydroxyapatite crystals

Question 6

what bone materials can change causing fragility fractures?

Answer 6

get advanced glycation end products which can damage collagen

Question 7

how can collagen be linked to fragility fractures?

Answer 7

mutations causing not enough or abnormal collagen

Question 8

Bone remodelling cycle

Answer 8

Quiescence, resorption, reversal, formation

Question 9

osteoclast action

Answer 9

resorption of bone

Question 10

How are osteoblasts activated?

Answer 10

growth factors are released by osteoclasts

Question 11

how do oestoblasts and osteoclasts change in menopause?

Answer 11

osteoclasts become more active than osteoblasts

Question 12

How are osteoclasts activated?

Answer 12

RANKL from osteoblasts binds and causes osteoclast precursors to mature

Question 13

Osteoprotegerin (OPG)

Answer 13

decoy receptor
blocks binding of RANK to RANK-L > reduces osteoclast differentiation
increases bone density

Question 14

How does menopause cause osteoporosis?

Answer 14

reduced oestrogen causes reduced Osteoprotegerin expression

osteoclasts more active

Question 15

mechanism of demosumab

Answer 15

decoy receptor for RANKL, mimics action of OPG

Question 16

how is demosumab administered?

Answer 16

6 monthly injection

Question 17

sclerostin

Answer 17

Made by osteocytes and suppresses bone formation

Question 18

Wnt pathway in osteoporosis

Answer 18

canonical wnt pathway enhances osteoblast differentiation, upregulates OPG and down regulates RANKL

Question 19

mechanism of romosozumab

Answer 19

antisclerostin antibody so enables Wnt system to remain active
get bone rebuilding

Question 20

2 monoclonal antibodies used in the treatment of osteoporosis

Answer 20

denosumab

romosozumab

Question 21

grancalcin

Answer 21

a protein that represses osteogenesis

Question 22

what secretes grancalcin?

Answer 22

senescent immune cells

Question 23

Osteoporosis

Answer 23

disorder of bone characterised by low bone mass and microarchitectural deterioration, increased fracture risk

Question 24

primary osteoporosis type 1

Answer 24

postmenopausal, accelerated decrease in bone mass that occurs when estrogen falls

Question 25

primary osteoporosis type 2

Answer 25

senile | affects men and women>70 yo

Question 26

Primary osteoporosis T1 vs T2

Answer 26

postmenopausal, accelerated decrease in bone mass that occurs when estrogen falls = t1 senile affects men and women>70 yo = t2

Question 27

which sex suffer from primary osteoporosis more?

Answer 27

females

Question 28

secondary osteoporosis

Answer 28

conditions in which bone is lost because of the presence of another disease, such as rheumatoid arthritis or certain drug use

Question 29

what drugs cause secondary osteoporosis?

Answer 29

``` steroids aromatase inhibitors anti-epileptics thyroxine proton pump inhibitors ```

Question 30

what determines bone mass?

Answer 30

- heredity - nutrition - exercise - hormone function

Question 31

DEXA

Answer 31

dual-energy x-ray absorptiometry

Question 32

which sites does DEXA image?

Answer 32

lumbar spine hip right forearm

Question 33

when do you DEXA scan right forearm?

Answer 33

in hyperparathyroidism or non-diagnostic spine/hip

Question 34

How does DEXA work?

Answer 34

measures bone density based on how easily low dose x-rays go through the bone

Question 35

T score

Answer 35

Standard deviation between BMD and that of a young healthy adult (30?)

Question 36

Z score

Answer 36

standard deviation between BMD and that of someone the same age

Question 37

what factors do the T and Z scores take into account?

Answer 37

gender and ethnicity

Question 38

normal T score for post menopausal women or men over 50

Answer 38

equal or greater than -1

Question 39

What T score shows osteoporosis?

Answer 39

equal or below -2.5

Question 40

what T score shows osteopenia?

Answer 40

what T score shows osteopenia? | between -1 and -2.5

Question 41

what does a Z score of below -2 mean?

Answer 41

BMD lower than it should be for someone age matched

Question 42

which score out of the sites imaged should you use for diagnostic purposes?

Answer 42

lowest score out of total spine, total hip, NOF or total forearm

Question 43

which DEXA score do you use for premenopausal women or men under 50?

Answer 43

Z score only

Question 44

FRAX

Answer 44

Fracture risk assessment tool developed by WHO

Question 45

what does FRAX use?

Answer 45

femoral neck BMD score | clinical risk factors e.g. age, steroid use, height

Question 46

what does FRAX calculate?

Answer 46

10yr risk of osteoporotic fracture

Question 47

do people under 50 need a low BMD for diagnosis of osteoporosis?

Answer 47

no, can give diagnosis if they have a fragility fracture regardless

Question 48

cortical bone

Answer 48

dense outer bone, strength determined by thickness and porosity

Question 49

trabecular bone

Answer 49

interior, spongy bone with a porous, honeycomb structure, strength determined by thickness, lattice number and porosity

Question 50

trabecular bone score

Answer 50

from textural analysis of DEXA | independent fracture risk assessment

Question 51

can the same BMD score have a different trabecular bone score?

Answer 51

yes

Question 52

HR-pQCT

Answer 52

research tool that does high res CT of wrist and ankles, looks at volume of bone

Question 53

what does osteoporosis look like on X-ray?

Answer 53

cortical thinning/increased radiolucency pencilling of vertebrae osteoporosis x-ray the time abnormalities defected by X-ray 25-30 % of bone tissue may have been lost

Question 54

interventional radiology - what is it?

Answer 54

image guided diagnostic or therapeutic procedures achieved through percutaneous puncture of a vessel or organ

Question 55

examples of IR

Answer 55

iliac angioplasty interventional oncology visceral embolisation stenting

Question 56

what are most preventable deaths from trauma caused by?

Answer 56

unrecognised haemorrhage, especially abdomen

Question 57

aortic transection

Answer 57

Injury to the aorta consisting of laceration of all 3 layers of the vessel wall

Question 58

Sign of aortic transection

Answer 58

aortic transection

Question 59

fatality rates in aortic transection

Answer 59

30% fatal within 6hrs, 40% in 24hrs

Question 60

what can you repair aortic transection with?

Answer 60

Dacron graft

Question 61

how can a fracture cause limb ischaemia?

Answer 61

how can a fracture cause limb ischaemia? | oedema or bone compresses artery causing ischaemia

Question 62

examples of embolic agents

Answer 62

coils cyanoacrylate glue temporary gelatin sponge

Question 63

Grades of renal trauma

Answer 63

Question 64

TACE interventional oncology

Answer 64

high dose chemo straight into tumour via arteries which feed them

Question 65

radiofrequency ablation

Answer 65

thin needle in core of tumor extends prongs, these are heated and cook tumour

Question 66

optimum tumour size for radio frequency ablation

Answer 66

2cm

Question 67

cryoablation

Answer 67

removing tumours with liquid nitrogen causing cell apoptosis