osteoporosis

Question 1

What is the definition of osteoporosis?

Answer 1

Osteoporosis is a quantitive bone defect where the bone mineral density is more than 2.5 standard deviations below the mean value for someone of the same age and sex

Reduced bone mineral density leads to increased bone fragility which carries the risk of fractures in response to minor trauma

Question 2

What is the definition of osteopenia?

Answer 2

Osteopenia is a bone mineral density which is between 1-2.5 standard deviations below the mean value for someone of the same age and sex

Question 3

Explain the pathophysiology of osteoporosis?

Answer 3

Throughout our lives our bones continually undergo remodelling in order to repair damage

Osteoblasts are responsible for the laying down of bone

Osteoclasts are responsible for the resorption of bone

The process of laying down and resorbing bone is normally a balanced process but in osteoporosis the activity of the osteoclasts exceeds the activity of osteoblasts and more bone is broken down than can be formed which results in a reduction in bone mineral density

Question 4

At what age do we physiologically start to loose bone mineral density?

Answer 4

When we reach around 30 years old there is a gradual reduction in osteoblast activity which causes a physiological reduction in bone mineral density

Question 5

At what point in a female’s life does bone mi mineral density fall by the greatest amount?

Answer 5

After the menopause females experience the greatest reduction in bone mineral density

This is because there is increased osteoclast activity because of the absence of the protective effect of oestrogen due to the cessation of ovarian function

Question 6

How many types of osteoporosis are there?

Answer 6

Type 1 is osteoporosis associated with the menopause

Type 2 osteoporosis is associated with advanced age

Question 7

List some of the risk factors for developing post-menopausal osteoporosis?

Answer 7

Smoking

Poor diet

Alcoholism

Lack of exercise

Being caucasian

Question 8

Which specific fractures usually occur in post-menopausal osteoporosis?

Answer 8

Colles fractures

Vertebral insufficiency fractures

Question 9

Which specific fractures usually occur in old-age osteoporosis?

Answer 9

Femoral neck fractures

Vertebral fractures

Question 10

What are causes of osteoporosis other than the menopause and ageing?

Answer 10

Steroids

Chronic Kidney Disease

Cushing’s syndrome

Alcoholism

Malnutrition

Hypothyroidism

Question 11

How do you diagnose osteoporosis?

Answer 11

DEXA bone scan

Serum calcium, phosphate and ALP are all IMPORTANTLY NORMAL

Question 12

pharmacological management

Answer 12

Vitamin D supplements, biphosphonates, denosumab, strontium ranelate

Question 13

names of biphosphonates

Answer 13

alodrenate and risedronate

Question 14

action of biphosphonates

Answer 14

reduce osteoclastic activity

Question 15

side effects of biphosphonates

Answer 15

may cause oesophageal irritation and dysphagia

Question 16

action of desunomab

Answer 16

monoclonal antibody which reduces osteoclastic activity

Question 17

action of strontium ranelate

Answer 17

increases osteoblastic activity and reduces osteoclastic activity

Question 18

zoledronic acid

Answer 18

once yearly IV biphosphonate but is extremely expensive

Question 19

use of hormone replacement therapy

Answer 19

not routinely recommended for post menopausal osteoporosis due to risk of DVT but can be used if other medications cannot be tolerated