Week 4 - I - Osteoporosis and bone disorders

Question 1

Progressive systemic skeletal disease characterised by low bone mass and microarchitectural deterioration of bone tissue, with a consequent increase in bone fragility and susceptibility to fracture - hard brittle bones

What is this?

Answer 1

Osteoporosis

Question 2

What is the condition which refers to a softening of your bones, often caused by a vitamin D deficiency? Soft bones are more likely to bow and fracture

Answer 2

Osteomalacia

Question 3

Is osteoporosis more common in men or women?

Answer 3

Osteoporosis is more common in women

Question 4

What are the 4 common fracture sites for osteoporosis?

Answer 4

Neck of femur

Vertebral body

Hip

Humeral neck

Question 5

What percentage of people with hip fractures die within a year of the fracture?

Answer 5

20% of people with hip fracture die within a year of the fracture

Question 6

What age group do the majority of hip fractures of osteoporosis occur in?

Answer 6

The majority of hip fractures occur in women over 75

Question 7

About 10% of the adult skeleton is remodelled each year How does the remodelling process take place? (what materiel is mineralized)

Answer 7

Bone undergoes a cycle of remodelling in a programmed sequence at discrete foci called bone remodelling units

Osteoclasts appear and begin to resorb bone, the osteoclasts are then replace by osteoblasts that fill the cavity made by producing osteoid which is mineralised to form new bone

Question 8

In osteoporosis, how does the bone remodelling cycle differ which causes the brittle bone? (left pic is osteoporosis, right is normal)

Answer 8

In osteoporosis, the rate of osteoclasts activity is greater than osteoblast activity leading to the increased bone loss

Resorption greater than formation

Question 9

What factors lead to an increased bone loss? (eg drugs, gender, hormones, what type of breast cancer)

Answer 9

Drugs - glucocorticoids lead to increased bone loss

Gender - females

Hormones - sex hormone deficiency causes bone loss (aromatase inhibitors in hormone receptor-positive breast cancer)

Menopause in women - decreased androgen leads to decreased oestrogen leads to bone loss

Question 10

What hormone deficiency is the major determinant of bone loss after the menopause ?

Answer 10

Oestrogen deficiency

Question 11

What are usually the factors that cause a person to be assessed for bone fractures? (the two sites are frax and QFracture)

Answer 11

Anyone over the age of 50 years

Anyone under 50 years with very strong clinical risk factors - Early menopause, Glucocorticoids

Question 12

What is the most widely used method of measuring bone mineral density?

Answer 12

A DEXA scan

Question 13

What is the normal standard deviation for bone mineral density?

Answer 13

Normal : BMD within 1 SD of the young adult reference mean

Question 14

Osteopenia a medical condition in which the protein and mineral content of bone tissue is reduced, but less severely than in osteoporosis. What is the bone mineral density of bones with osteopenia? (standard deviation) What is osteoporosis BMD?

Answer 14

Greater than 1 but less than 2.5 standard deviations below the young adult mean

Osteoporosis is BMD greater than 2.5 SD below the young adult mean

Question 15

What are some secodnay causes of osteoporosis? (endocrine, GI and resp)

Answer 15

Endocrine eg hyperthyroidism, hyperparathyroidism, Cushing’s disease

Gastrointestinal eg coeliac disease, IBD, chronic liver disease, chronic pancreatitis

Respiratory eg CF, COPD

Question 16

How can hyperthyoridism cause osteoporosis?

Answer 16

Too much thyroxine can increase the rate of bone turnover and if the body cannot keep up the rate of new bone formation then this will decrease the bone mineral density

Question 17

What should be avoided to decrease risk of osteoporosis?

Answer 17

Avoid smoking and alcohol

And glucocorticoids if possible

Question 18

What is the recommended nutrient intake of calcium in the diet?

Answer 18

700mg calcium minimum

Question 19

In people who are at a deficiecny of sunlight exposure, and are therefore at a risk of fractures, what supplements can be given to help?

Answer 19

Give calcium and vit D supplements

Question 20

Your T-score is the number of units — called standard deviations — that your bone density is above or below the average. What does the T score have to be to give the first line treatment for osteoporosis? What is the first line treatment? (the drug type and example)

Answer 20

T score less than -2.5

First line treatment is oral biphophonates - alendronic acid (alendronate) or risendronic acid (risendronate)

Question 21

If the patient is not suitable for oral biphosphonates what is given? (this is also the second line treatment) How is it given?

Answer 21

Zolendronic acid - it is a once yearly IV infusion for 3 years

Question 22

fully human monoclonal antibody used in treatment of osteoporsis - high risk fracture patients Given as 6monthly SC injections WHat is this? (alternative second line)

Answer 22

Denosumab

Question 23

What is a rare side effect of long term biphosphonate treatment? (and two other side effects)

Answer 23

Damage to the jaw bone (osteonecrosis)

Oesophagitis

Hypocalcaemia / tired

Question 24

What are three side effects of denosumab?

Answer 24

Eczema Cellulits Hypocalcaemia

Question 25

If patient has severe spinal osteoporosis, what should be considered for bone treatment?

Answer 25

Teriparatide - recombinant parathyroid hormone

Question 26

What is final line treatment for osteoporosis if other treatments do not work or are contra-indicated?

Answer 26

Strontium ranelate

Contra-indicated in history of vascular disease

Question 27

When are the majority of treatments considered for treatment with an anti-resorptive agent?

Answer 27

When when T score = - 2.5

Question 28

What are the direct effects that glucocorticoids have on bone?

Answer 28

Decrease osteoblasts activity

Reduction in calcium absorption

Question 29

What is the disease of the bone characterized by abnormal osteoclasts activiity followed by increased osteoblastic activity?

Answer 29

Paget’s disease of the bone - causes abnormal bone structure with reduced strength and increased fracture risk

Question 30

How is paget’s diagnosed? (what scan and what is biochemistry findings)

Answer 30

diagnose on XR,

isotope bone scan shows distribution

raised alkaline phosphatase with normal LFTs (normal calcium, phosphorus and PTH)

Question 31

How is paget’s treated?

Answer 31

Give biphosphonates and analgesics for pain

Question 32

rare group of genetic disorders mainly affecting bone most secondary to mutations of type 1 collagen genes Causes blue sclera What is this?

Answer 32

Osteogenesis imperfecta or brittle bone disease