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Flashcards in Bone disorders Deck (34):
1

What are common fractures?

neck of femur; vertebral body; distal radius; humeral neck

2

What is the name for the discrete foci where bone undergoes a cycle of remodelling?

bone remodelling units

3

What happens during a normal bone cycle?

osteoclasts appear on a previously inactive surface and begin to resorb the bone; osteoclasts are then replaced by osteoblasts that fill the cavity by putting down osteoid that is mineralised to form new bone and then after a full cycle the resoption cavity is completely refilled with new bone

4

What happens in osteoporosis in compared to a normal cycle?

thre is a relative or absolute increase in resrption over formation that leads to increased bone loss

5

What is the major determinant of bone loss for women after menopause?

oestrogen deficiency

6

What are the modifiable risk factors for fragility fracture?

BMD; alcohol; weight; smoking; physical inactivity

7

What are non-modifiable risk factors for fragility fractures?

age; gender; ethnicitiy; previous fractures; family history; early menopause < 45 yo

8

Who should have theirr OP risk factors asses?

anyone over age 50 with risk factors; anyone under 50 with very strong risk factors eg early menpause or glucocorticoids

9

Who sohuld be referred for a DXA?

anyone with a 10 year risk assessment for any OP fracture of at last 10%

10

What is osteopaenia defined as?

BMD >1SD below the young adult mean but <2.5 SD below this value

11

What is osteoporosis?

BMD greater than or equal to 2.5 SD below the young adult mean

12

What is severe osteoporosis defined as?

osteoporosis with a fragility fracture

13

What are the secondary cuases of osteoporosis?

endocrine- hyperthyroidism; hyperparathyroidism; Cushings; GI- coeliac; IBD; chronic liver disease; chronic pancreatitis; resp- CF; COPD; chronic kidney disease

14

What is the lifestyle advice for management of osteoporosis?

high intensity stergth training; low impact weight bearing exerccise; avoidance of excess alcohol; avoidance of amoking; fall prevention

15

Who should calcium and vitamin D supplements be considered in?

pts who are at risk of deficieny due to insufficent dietary or limited sunlight exposure

16

When should calcium supplements be taken in relation to bisphosphonates?

should not be taken within 2 hours

17

Name 2 bisphosphonates

alendronate; risedronate

18

What is the action of bisphosphonates?

anti-resorptive agents- analogues of pyrophosphate that adsorb onto bone within the matrix and are ingested by osteoclasts leading to cell death thereby inhibiting bone resorption

19

What ar ethe benefits of bisphosphonates

which prevent bone loss at all sites vulnerable to osteoporosis and reduce risk of hip and spine fracture

20

What ar ethe long term risks of bisphosphonates?

osteonecrosis of the jaw; oseophhageal Ca; atypicla fractures

21

How is zoledronic acid administered?

once yearly IV infusion for 3 years

22

What is the action of denosumab?

fully human monoclonal Ab that targets and binds with high affinity and specificity to RANKL which prevents activation of its receptor RANK, inhibiting development and activity of osteoclasts, decreasing bone resoprtion and increasing bone density

23

How is denusomab give?

aubcut injection every 6 months

24

What are the adverse effects of denusomab?

hypocalcaemia; eczema; cellulitis

25

Who is strontium ranelate CI in?

if Hx of thromboembolic disease; IHD; periphera; arterial disease; uncontrolled HT

26

What is teriparatide?

recombinant parathyroid hormone that stimulates bone growth rather than reducing bone loss-anabolic agent

27

What are the effects of steroids on bone?

reduction of osteoblast activity and lifespan; suppression of replication of osteobalst precursors; reduction in calcium absorption; increase PTH

28

How much BMD is lost in 1st 6 months of steroid use?

30%

29

What happens during Paget's disease?

abnormal osteoclastic activity followed by increased osteoblastic activity; abnormal bone structure with reduced strength and increased fracture risk

30

What bones does Paget's affect?

long bones; pelvis; lumbar spine and skull

31

How does Paget's present?

in older populations; with bone pain; deformity, deafness or compression neuropathies

32

How is Paget's treated?

bisphosphonates if pain not responding to analgesi

33

What is the mutation foudn in osteogenesis imperfecta?

in type 1 collagen genes

34

What is osteogenesis imperfecta associated with?

blue sclera and dentiogensis imperfecta