Bone Disease

Question 1

what is osteoporosis

Answer 1

decreased mass of structurally normal bone - trabecular bone loss - cortical thinning

Question 2

risk factors for osteoporosis

SHATTERED pneumonic

Answer 2

Steroids

Hyperthyroidism

Alcohol + smoking

Thin (BMI <22)

Testosterone low

Early menopause

Renal / liver failure

Erosive / inflammatory bone disease (e.g. RA)

Dietary Ca deficient

Question 3

relationship between osteoporosis and OA

Answer 3

osteoporosis reduces OA risk

Question 4

presentation of osteoporosis

Answer 4

fragility fractures from low impact trauma that would not cause fracture in healthy bone e.g. NOF

vertebral fractures - vertebral collapse. Leads to back pain + height reduction – thoracic kyphosis

Question 5

what scan is used to diagnose osteoporosis

Answer 5

DEXA scan

Question 6

What is a T score

What is a Z score

on DEXA scan

Answer 6

T = no. of standard deviations away from youthful average

Z = no. of standard deviations away from age matched average (used in pre-menopausal women)

Question 7

what T score is normal?

Answer 7

> -1

Question 8

what T score indicates osteomalacia

Answer 8

-1 - -2.5

Question 9

what T score indicates osteoporosis

Answer 9

< -2.5

Question 10

what is FRAX score

Answer 10

gives 10 year fracture risk in patients aged 40-90

Question 11

1st line fracture prevention in osteoporosis

Answer 11

bisphosphonates (alendronate)

+ calcium + vit D supplements

Question 12

mechanism of action bisphosphonates

Answer 12

increase osteoclast apoptosis – reducing bone breakdown

Question 13

side effects of bisphosphonates

Answer 13

GI inflammation - pain, dyspepsia

osteonecrosis of jaw

photosensitivity

Question 14

how must bisphosphonates be taken to reduce GI side effects

Answer 14

take on empty stomach with lots of water

stay upright for 30 mins after taking

Question 15

2nd line therapy for fracture prevention in osteoporosis

Answer 15

strontium ranelate - bisphosphonate alternative

Denosumab - anti-RANKL, decreases osteoclast activation

Teriparetide - PTH analogue, new bone formation

Question 16

what is osteomalacia

Answer 16

decreased bone mineral content

Question 17

biochemistry in osteomalacia

Answer 17

low calcium

low PO4

high ALP

high PTH

Question 18

symptoms of osteomalacia

Answer 18

bone pain + tenderness

fractures

proximal myopahty due to decrease PO4

Question 19

What is osteomalacia called in children?

How does it present?

Answer 19

Rickets

Knock kneed/ bow legged

Bone pain

Question 20

what is seen on xray in rickets

Answer 20

cupped metaphyses

Question 21

treatment of osteomalacia

Answer 21

calcium + vit D supplementation

Question 22

what are Looser’s zones

Answer 22

pseudofractures seen on XRAY osteomalacia

Question 23

symptoms of hypocalcaemia

SPASMODIC pneumonic

Answer 23

Spasms: +ve Trousseau’s sign

Perioral Parasthesia

Anxious

Seizures

Muscle tone increase

Orientation impaired (confusion)

Dry skin/dermatitis

Impetigo herpetiformis

Chovsteks- facial twitch on parotid tap

Question 24

aldendronate can increase risk of what type of fracture

Answer 24

aytypical stress fracture of femoral shaft

Question 25

how can:

phenytoin

atorvastatin

affect vitamin D

Answer 25

phenytoin - lower vitamin D levels

Atorvastatin - increase vitamin D levels

Question 26

what is Pagets Disease

Answer 26

increased bone turnover

• bone resorption by osteoclasts followed by chaotic bone deposition by osteoblasts
• most commonly affects skull, spine, pelvis, long bones
• thickened + sclerotic bone on XRAY

Question 27

typical presentation of Pagets

Answer 27

elderly man with bone pain with raised ALP

Question 28

biochemistry results in pagets

Answer 28

Raised ALP

calcium + phosphate normal

Question 29

treatment of Pagets

Answer 29

Bisphosphonates

Question 30

differentials of a raised ALP + raised calcium

Answer 30

bone metastasis

hyperparathyroidism

Question 31

differentials of a raised ALP + low calcium

Answer 31

osteomalacia

renal failure