Metabolic Bone disease 2 (Osteoporosis)

Question 1

What is Osteoporosis:

Answer 1

A metabolic bone disease characterised by low bone mass and micro architectural deterioration of bone tissue, leading to enhanced bone fragility and a consequent increase in fracture risk

Question 2

What are risk factors for Osteoporosis

Answer 2

Older age

Female

Reduced mobility and activity

Low BMI (<18.5 kg/m2)

Rheumatoid arthritis

Alcohol and smoking

Long term corticosteroids.

Other medications such as SSRIs, PPIs, anti-epileptics and anti-oestrogens

Question 3

What is a key group where osteoporosis should be considered.

Answer 3

Post-menopausal women because Oestrogen is protective against osteoporosis.

Unless they are on HRT postmenopausal women have less oestrogen. They also tend to be are older and often have other risk factors for osteoporosis.

Question 4

What can you use to calculate the fracture risk of bones

Answer 4

FRAX tool

Question 5

What is the FRAX tool

Answer 5

The FRAX tool gives a prediction of the risk of a fragility fracture over the next 10 years. This is usually the first step in assessing someone’s risk of osteoporosis.

Question 6

How do you measure bone mineral density

Answer 6

Dual energy xray absorptiometry (DEXA)

Question 7

What are Dual energy xray absorptiometry (DEXA)

Answer 7

DEXA scans are brief xray scans that measure how much radiation is absorbed by the bones, indicating how dense the bone is

Question 8

Where do you scan with a DEXA

Answer 8

The bone mineral density (BMD) can be measured at any location on the skeleton, but the reading at the hip is key for the classification and management of osteoporosis.

Question 9

How is Bone density can be represented in a DEXA

Answer 9

Z score

T score

Question 10

What is a Z score

Answer 10

Z scores represent the number of standard deviations the patients bone density falls below the mean for their age.

Question 11

What is a T score

Answer 11

T scores represent the number of standard deviations below the mean for a healthy young adult their bone density is.

Question 12

What DEXA score forms the basis for the WHO classification of a level of osteoporosis

Answer 12

T score at the persons hip

Question 13

What is the Epidemiology of Osteoporosis

Answer 13

I in 2 women over 50 will have an osteoporotic fracture before they die

I in 5 men over 50 will suffer and osteoporotic fracture

A 50 year old woman has a lifetime risk of 17% of a hip fracture

Question 14

What can be done prophylactically to prevent fractures

Answer 14

Minimise risk factors

Ensure good calcium and

Vitamin D/calcium status

Falls prevention strategies

Medications

Question 15

What is the first step in assessment of risk of osteoporosis

Answer 15

The first step is to perform a FRAX assessment on patients at risk of osteoporosis:

Question 16

Who do you perform FRAX on

Answer 16

Women aged > 65

Men > 75

Younger patients with risk factors such as a previous fragility fracture, history of falls, low BMI, long term steroids, endocrine disorders and rheumatoid arthritis.

Question 17

What is first line medication used in osteoporosis

Answer 17

Oral Bisphosphonates generally the first line of treatment

Question 18

How do Bisphosphonates work?

Answer 18

They work by interfering with osteoclasts and reducing their activity, preventing the reabsorption of bone. There are a few key side effects to remember:

Question 19

What are the side effects of Bisphosphonates

Answer 19

Reflux and oesophageal erosions.

Atypical fractures (e.g. atypical femoral fractures)

Osteonecrosis of the jaw

Osteonecrosis of the external auditory canal

Question 20

How are Bisphosphonates taken?

Answer 20

Oral bisphosphonates are taken on an empty stomach sitting upright for 30 minutes before moving or eating to prevent this.

Question 21

What are 3 bisphosphonate medications

Answer 21

Alendronate 70mg once weekly (oral)

Risedronate 35 mg once weekly (oral)

Zoledronic acid 5 mg once yearly (intravenous)

Question 22

Apart from bisphosphonates what other medications can be used in osteoporosis

Answer 22

Denosumab

Strontium ranelate

Raloxifene

Hormone replacement therapy (HRT)

Question 23

What is Denosumab

Answer 23

Denosumab is a monoclonal antibody that works by blocking the activity of osteoclasts.

Question 24

What is Strontium ranelate

Answer 24

Strontium ranelate is a similar element to calcium that stimulates osteoblasts and blocks osteoclasts but increases the risk of DVT, PE and myocardial infarction.

Question 25

What is Raloxifene

Answer 25

Raloxifene is used as secondary prevention only. It is a selective oestrogen receptor modulator that stimulates oestrogen receptors on bone but blocks them in the breasts and uterus.

Question 26

What is Hormone replacement therapy

Answer 26

Hormone replacement therapy should be considered in women that go through menopause early.