Disorders of bone health including osteoporosis

Question 1

What is osteoporosis?

Answer 1

Progressive skeletal disease characterised by low bone mass and microarchitectual deterioration of bone structure

Question 2

Which sex gets osteoporosis more commonly?

Answer 2

Women

Question 3

How does osteoporosis present?

Answer 3

Asymptomatic until fractures

Question 4

Over which age is osteoporosis frequent?

Answer 4

50

Question 5

What are the common osteoporotic fracture sites?

Answer 5

Neck of femur
Vertebral body
Distal radius
Humeral neck

Question 6

What is the domino effect in relation to osteoporosis?

Answer 6

An increasing number of vertebral fractures due to osteoporosis causing progressive curvature of the spine

Question 7

Where does bone remodelling occur?

Answer 7

Bone remodelling units

Question 8

Describe bone remodelling

Answer 8

Osteoclasts begin to reabsorb bone at specific sites >
Osteoclasts replaced by osteoblasts which lay down osteoid >
Osteoid undergoes mineralisation to bone >
Resorptive cavity completely filled with new bone

Question 9

How is bone remodelling altered in osteoporosis?

Answer 9

Reabsorption of bone occurs more than formation

Question 10

How is osteoporotic bone architecture different from normal bone?

Answer 10

Large spaces and breaks

Weakened

Question 11

Which factors are important in bone density?

Answer 11

Body weight
Genetics
Sex hormones 
Diet 
Exercise

Question 12

Which factors contribute to bone density loss?

Answer 12

Lowered sex hormones (menopause)
Low body weight
Poor genetics
Calcium deficient diet 
Immobility 
Disease affecting bones
Drugs (e.g steroids)

Question 13

How does bone density change with age?

Answer 13

Bone density increases until around 30
After 40 it begins to decline slowly
During and after menopause bone density loss is rapid and oestrogen deficiency can further perpetuate this

Question 14

What are the non-modifiable risk factors for fragility fractures?

Answer 14

Age 
Gender
Ethnicity 
Previous fracture
Family history 
Early menopause (

Question 15

What are the modifiable risk factors for fragility fractures?

Answer 15

Bone mineral density 
Alcohol
Low weight
Inactivity 
Diet 
Smoking 
Pharmacological (steroids)

Question 16

Which diseases increase the risk factor for an osteoporotic fragility fracture?

Answer 16

Rheumatoid arthritis
Hyperthyroidism
Chronic liver disease
Hypogonadism
Diabetes
Dementia

Question 17

Who should be risk assessed?

Answer 17

Patients over 50 with risk factors

Patients under 50 with serious risk factors (steroids, early menopause)

Question 18

Who should be referred for a dexa bone scan?

Answer 18

High risk patients

Question 19

How is bone mineral density measured?

Answer 19

DEXA bone scan

Question 20

Is bone mineral density a dependent or independent risk factor for fragility fractures?

Answer 20

Independent

Question 21

What is osteopenia?

Answer 21

Low bone density above 1 standard deviation below expected

Question 22

What is osteoporosis?

Answer 22

Low bone density over 2 and a half standard deviations below expected

Question 23

What is severe osteoporosis?

Answer 23

Low bone density over 2 and a half standard deviations below expected + fragility fracture

Question 24

How can osteoporosis be classified in patients younger than 20?

Answer 24

Using the z score

Question 25

As bone mineral density increases what happens to the risk of fracture?

Answer 25

Decreases

Question 26

How should suspected osteoporosis be investigated?

Answer 26

``` U&E LFT Bone biochemistry FBC PV TSH Protein electrophoresis/bence jones proteins (myeloma) Coeliac antibodies Testosterone levels Vitamin D Parathyroid hormone ```

Question 27

List some secondary causes of osteoporosis

Answer 27

``` Hyperthyroidism Hyperparathyroidism Cushing's disease Coeliac IBD Chronic liver disease Chronic pancreatitis Cystic fibrosis COPD Chronic kidney disease ```

Question 28

What lifestyle changes can be helpful in the management of osteoporosis (not diet)?

Answer 28

``` Risk assessment for falls and prevention High intensity strength training Low intensity weight bearing Smoking cessation Avoidance of alcohol excess ```

Question 29

What diet changes can be helpful in the management of osteoporosis?

Answer 29

2-3 portions of milk/dairy per day (700g) 3-4 portions of milk/dairy per day (1000g) post menopausal Non dairy sources (bread, fortified cereal, fish w/ bones, green veg, beans)

Question 30

When are calcium and/or vitamin D supplements indicated?

Answer 30

Considered as risk reduction of non-vertebral fracture in patients at risk of deficiency due to diet or limited sunlight (housebound, cultural garb)

Question 31

When should calcium not be taken?

Answer 31

Within two hours of oral biphosphonates

Question 32

When would vitamin D alone be indicated?

Answer 32

When oral calcium intake is adequate

Question 33

How do biphosphonates work?

Answer 33

Anti-resorptive agents - analogues of pyrophosphate that get absorbed onto bone and eaten by osteoclasts causing cell death and less reabsorption

Question 34

Give two examples of biphosphonates

Answer 34

Alendronate | Risedronate

Question 35

What do biphosphonates reduce the risk of?

Answer 35

Spine and hip fractures

Question 36

When are biphosphonates indicated?

Answer 36

T score less than -2.5 | Existing fragility fracture

Question 37

How long should biphosphonates be given for?

Answer 37

5 yr + | 10 yr + if vertebral fracture

Question 38

What are the risks of long term biphosphonate use?

Answer 38

Osteonecrosis of the jaw Oesophageal carcinoma Atypical fractures

Question 39

How is zoledronic acid given?

Answer 39

Once yearly IV infusion (5mg in 100ml NaCl) for 5 years

Question 40

What is a common side effect of zoledronic acid and how can this be treated?

Answer 40

Influenza like symptoms (acute phase reaction) | Paracetamol

Question 41

How does denosumab work?

Answer 41

Human monoclonal antibody targeting RANKL - inhibiting activation, development of osteoclasts and decreased reabsorption so increased density

Question 42

How is denosumab administered?

Answer 42

Subcutaneous injections 6 monthly

Question 43

Which osteoporosis drug can be administered in severe renal failure?

Answer 43

Denosumab

Question 44

What are the side effects of denosumab?

Answer 44

Hypocalcaemia Eczema Cellulitis

Question 45

What is strontium ranelate?

Answer 45

Antireabsorptive agent

Question 46

When is strontium ranelate contraindicated?

Answer 46

Thromboembolic disease Ischaemic heart disease Peripheral artery disease Uncontrolled hypertension

Question 47

When is strontium ranelate indicated?

Answer 47

When there is no other option

Question 48

What is teriparatide?

Answer 48

Recombinant parathyroid hormone

Question 49

How does teriparatide work?

Answer 49

Stimulates bone growth

Question 50

When is teriparatide indicated?

Answer 50

Over 65 with T score -3.5 plus 2 fragility fractures | 55-64 with T score

Question 51

When should patients be treated for osteoporosis?

Answer 51

Anti-resorptive therapy T score 7.5 for 3 months or more OR prevalent fracture and T score

Question 52

What are the direct and indirect effects of corticosteroids on bone?

Answer 52

Direct - reduced osteoblast activity, suppression of osteoblast growth and reduction in calcium absorption Indirect - reduced gonadal and adrenal hormones

Question 53

Are the fracture risks of glucocorticoids dose dependent?

Answer 53

Yes but no safe dose

Question 54

What is Paget's disease?

Answer 54

Abnormal osteoclast activity followed by increased osteoblast activity resulting in weakened bone and increased fracture risk

Question 55

What is the term for paget's at a single site? What about at multiple sites?

Answer 55

Monostotic | Polystotic

Question 56

What is the aetiology of Paget's?

Answer 56

Unknown

Question 57

Which bones does Paget's affect?

Answer 57

Long bones Pelvis Lumbar spine Skull

Question 58

Which age group is affected by Paget's?

Answer 58

Over 55

Question 59

How does Paget's disease present?

Answer 59

Bone pain Deformity Deafness Compression neuropathies

Question 60

What is a rare complication of Paget's?

Answer 60

Osteosarcoma

Question 61

How can Paget's be investigated?

Answer 61

X-ray Isotope bone scan Isolated raise on alkaline phosphate Normal LFTs

Question 62

How is Paget's treated?

Answer 62

Analgesia +/- biphosphonates if not responding

Question 63

What is osteogenesis imperfecta?

Answer 63

Group of autosomal dominant genetic conditions arising from mutations in type 1 collagen

Question 64

How many types of osteogenesis imperfecta are there?

Answer 64

8 types Neonatal lethal - type 2 Very severe - type 3 and 4 Mild - type 1

Question 65

What is osteogenesis imperfecta associated with?

Answer 65

Blue sclera | Dentinogenesis imperfecta

Question 66

How do severe forms present?

Answer 66

Childhood fractures

Question 67

How is osteogenesis imperfecta treated?

Answer 67

Fixation Surgery for deformity Biphosphonates

Question 68

What is osteogenesis imperfecta an important differential of?

Answer 68

Non-accidental injury