Osteoporosis

Question 1

Risk factors for fragility fracture / osteoporosis?

Answer 1

1. Previous low trauma fracture (standing height or less)
2. Inflammatory disease (RA, IBD, connective tissue disease)
3. Endocrine disease (hypogonadism inc. early menopause, hyperparathyroidism, hyperthyroidism, Cushing’s)
4. Malabsorption (Coeliac)
5. Low BMI
6. Immobility (Spinal injury)
7. Medication (Corticosteroids, aromatase inhibitors, GnRH analogues, Depo-provera)
8. Family history (Hip fracture)
9. Lifestyle (Alcohol and Vit D Deficiency)

Question 2

How is a DXA score interpreted?

What scores are relevant?

Answer 2

T-score is key point
standard deviation
compared with gender-matched young adults average

< -1 - 0 = normal
- 2.5 - -1 = osteopenia
< - 2.5 = osteoporosis

Z-score shows how they compare to their age group

Question 3

Available drug mechanisms and names? (4)

Answer 3

Anti-resporptive (decrease osteoclast activity):
Bisphosphonates
HRT
Denosumab

Anabolic (increase osteoblast activity and bone formation)
Teriparatide

Question 4

What is the mechanism of action of bisphoshonates

Answer 4

Anti-resorptive - decrease osteoclast activity.

High affinity for hydroxyapatite, attaches to bone surface
Ingested by osteoclast, disables osteoclast, reduces bone resorption.

Question 5

Bisphosphonate dosing instructions?

Answer 5

Take first thing in morning on an empty stomach (absorption is poor, about 5%)
Take with a big glass of water
Nothing else to eat or drink for 30 minutes
Don’t lie down after taking

Question 6

Bisphosphonate side effects?

Answer 6

Can cause oesophagitis (reduce risk by dosing) 
IV can cause flu-like illness
Atrial fibrillation
Rare: 
Osteonecrosis of the jaw
Atypical femoral fractures

Question 7

What is osteoporosis?

Answer 7

A systemic skeletal disease characterised by low bone mass and microachitectural deterioration of bone tissue, with a consequent increase in bone fragility and susceptibility to fracture.

Question 8

What are the main locations for osteoporotic fracture?

Answer 8

Wrist (Colles fracture)
Proximal femur fracture
Vertebral fracture

Question 9

Prevalence?

Answer 9

1:2 women
1:5 men
over the age of 50

Question 10

By how much does osteoporosis medication reduce fracture risk?

Answer 10

50%

Question 11

What is the morbidity and mortality in the first year post hip fracture?

Answer 11

20% mortality
30% permanent disability
80% unable to carry out at least one ADL

Question 12

What is bone strength compromised of?

Answer 12

Bone mineral density
Bone size
Bone quality

Question 13

What is the effect of osteoporotic drugs?

Answer 13

Reduce bone turnover by decreasing osteoclast activity and increasing osteoblast activity.

Decreases resorption and increases formation.

Question 14

How can risk be quantified? (2)

Answer 14

Clinical risk calculators

Bone densitometry

Question 15

What are the clinical risk factor calculators?

Who are the used in?

Answer 15

Qrisk score
FRAX score

Women over 65, Men over 75, or those with risk factors.

Question 16

What are the bone densitometry scans?

Answer 16

Dual x-ray absorpitometry (DXA)

Vertebral fracture assessment (VFA)

Question 17

What is a vertebral fracture assessment?

Why are they useful?

Answer 17

Uses DXA machine and low dose x-ray to identify prevalence vertebral fractures (only 30% diagnosed at time)

Vertebral fractures indicate very high risk of future fracture.

Question 18

What further investigations might you perform if there is evidence of low BMD or vertebral fractures?

Answer 18

Calcium, PTH, vitamin D
Serum and urine electrophoresis (myeloma)
TSH
Coeliac antibody
FBC, ESR
Sex hormones

Question 19

What are the management categories/ options for osteoporosis?

Answer 19

Identify and treat underlying cause e.g. hypogonadism
Lifestyle modification e.g. smoking, alcohol, calcium and vitamin D
Drug therapy

Question 20

Why are bisposphonates first line?

Answer 20

Cheap
Effective - 50% fracture reduction
Many years experience

Question 21

Give some examples of bisphosphonate medications (5)?

Answer 21

Oral:
Alendronate (daily or weekly)
Risedronate (daily or weekly)
Ibandronate (monthly)

IV:
Ibandronate (3-monthly)
Zoledronate (once yearly)

Question 22

How can HRT be used for the prevention of osteoporosis?

Answer 22

Reduces risk by about 50%
Also prevents other menopausal symptoms
Okay if no contraindications

Question 23

What are some risks of HRT?

Answer 23

Breast cancer
Stroke
Cardiovascular disease
Venous thrombo-embolic disease

Question 24

What is Denosumab and how does it work?

Answer 24

Monoclonal antibody to RANK ligand

Prevents osteoclast differentiation and reduces activity

Question 25

What should you do as a junior doctor if you notice a vertebral fracture on any imaging?

Answer 25

Refer for a DXA scan
(or check previous one)
Check taking bisphosphonates correctly

Question 26

Why is it important to pick up?

Answer 26

Increases the risk of fragility fractures (low/no fracture factures)

Question 27

If Qrisk score or FRAX score are high, what would you do?

Answer 27

DXA scan or BMD scan

Lowest score used

Question 28

What risk reducing advice may you give?

Answer 28

Stop smoking
Reduce alcohol
Lose weight
Take vitamin D and C
Take bisphosphonates