metabolic bone disease

Question 1

What controls the bone turnover

Answer 1

Osteoblasts

Question 2

How do osteoblasts stimulate osteoclasts

Answer 2

Release RANK ligand which binds to the osteoclasts causing the intake of nuclei into the osteoclast and then the osteoclast divide which allows for more bone resorption

Question 3

What stimulates osteoblasts

Answer 3

vitamin D

Question 4

Where do we get vitamin D from

Answer 4

Sun
Oily fish and egg yolks

Question 5

Describe the production of Vitamin D

Answer 5

UVB change 7DHC on the skin into the preform of vitamin D

the liver then changes this into 25(OH) vit D - which is the storage form

The kidney then changes the storage form into 1,25(OH)Vit D which is the active form for use

Question 6

What Vitamin D is checked when doing tests

Answer 6

the storage vitamin D - 25(OH)vit D

Question 7

What is the function of Vitamin D

Answer 7

Maintaining extracellular fluid calcium levels

Question 8

What is Paget’s disease of bone

Answer 8

Increased bone resorption followed by increased bone formation which leads to a disorganised bone

Question 9

What are the features of a bone after Paget’s disease

Answer 9

Bigger, less compact, more vascular and more susceptible to deformity and fracture

Question 10

What genes are correlated with Paget’s disease

Answer 10

Loci of SQSTM1

Question 11

What environmental triggers are thought to cause pagets disease

Answer 11

Chronic viral infection within osteoclasts

Question 12

What are the symptoms of Paget’s disease

Answer 12

Over 40 years old patient presents with bone pain

Occasional deformity

Heat over the Pagetic bone due to the increased vascularity

Neurological complications - nerve deafness

Question 13

What age is paget’s commonly in

Answer 13

Has to be over 40 at least but commonly around 60

Question 14

What is the main way of diagnosing Paget’s disease

Answer 14

Bone scan

Question 15

What is the common presentation of Paget’s -including bloods

Answer 15

Increased ALP

Bone pain and local heat

bone deformity or fracture

hearing loss

rare development of osteosarcoma in the affected bone

Question 16

What is the treatment of Paget’s disease

Answer 16

IV bisphosphonate therapy - one off - first line - IV zoledronic acid

Question 17

Should you treat someone with asymptomatic Paget’s disease

Answer 17

No unless the Paget’s is in their skull which would cause them nerve deafness

Question 18

What causes rickets and osteomalacia

Answer 18

severe vit D or calcium deficiency

Question 19

What is the difference between rickets and osteomalacia

Answer 19

Rickets occurs in children before the epiphyseal plates fuse while osteomalacia occurs in adults after the epiphyseal plate fuses

Question 20

How do rickets and osteomalacia look on blood tests

Answer 20

Low calcium
raised alp
Raised PTH
very low vitamin D

Question 21

How does rickets present

Answer 21

The fontanelles haven’t closed
Large forehead
odd shaped ribs and breast bone
odd curve to spine
Their epiphysis widen so there are more prominent parts on the bone

Question 22

What is the treatment for Rickets and osteomalacia

Answer 22

Calcium and vitamin D supplements

Question 23

On Xray what is a common finding in osteomalacia

Answer 23

Micro - fractures

Question 24

What is osteogenesis imperfecta

Answer 24

Genetic disorder of connective tissue that is characterised by fragile bones which can fracture from mild trauma and normal daily acts

Question 25

What causes osteogenesis imperfecta

Answer 25

Defects in type one collagen

Question 26

What are the signs and symptoms of osteogenesis imperfecta

Answer 26

growth deficiency defective tooth formation hearing loss blue sclera scoliosis barrel chest ligamentous laxity easily bruised

Question 27

What scoring system measures hypermobility

Answer 27

The beighton score

Question 28

What is the management of osteogenesis imperfecta

Answer 28

Surgical - to treat fractures IV bisphosphonates to prevent the fractures

Question 29

What is osteoporosis

Answer 29

Metabolic bone disease characterised by low bone mass and micro-architectural deterioration of bone tissue which leads to bone fragility and increase in fracture risk

Question 30

What is the definition of osteoporosis on a bone density scan (DXA bone scan)

Answer 30

If you are more than 2.5 standard deviations below the young adult mean

Question 31

Why is osteoporosis in women over 50 common

Answer 31

There is an accelerated loss of bone when menopause begins

Question 32

Which gender most commonly gets osteoporosis

Answer 32

women but it is common in men

Question 33

Which age group is osteoporosis more common in

Answer 33

Older age

Question 34

How common is it to break fracture in men and women over 50

Answer 34

50% of women over 50 20% of men over 50

Question 35

What are endocrine causes of osteoporosis

Answer 35

Thyrotoxicosis - hyper thyroidism hyper and hypoparathyroidism cushings hyperprolactinaemia hypopituitarism early menopause

Question 36

What are the rheumatic causes of osteoporosis

Answer 36

Inflammatory conditions: Rheumatoid arthritis ankylosing spondylitis polymyalgia rheumatica

Question 37

What are GI causes of osteoporosis

Answer 37

UC and crohns Liver disease - Primary biliary cirrhosis, chronic alcoholic hepatitis, alcoholic cirrhosis and viral cirrhosis (HEP C) Malabsorption - chronic pancreatitis , coeliac disease, whipples, short gut and ischaemic bowel

Question 38

What medications cause osteoporosis

Answer 38

Steroids PPI Enzyme inducing anti epileptic medications Aromatase GnRH inhibitors Warfarin

Question 39

What is the management of osteoporosis

Answer 39

Minimise risk factors of fractures Ensure good intake of calcium and vitamin D medications

Question 40

What medications are given in osteoporosis

Answer 40

Bisphosphonates are first line Antiresorptive therapy - prevent breakdown of bone - HRT - hormone replacement therapy , SERMs - selective oestrogen receptor modulators , Biphosphonates and denosumab Anabolic therapies - teriparatide - PTH analogue and romosuzumab - antiscerostin agent

Question 41

What are the side effects of HRT

Answer 41

Increased risk of blood clots Increased risk of breast cancer if used into late 50s Increased risk of heart disease and stroke if used after long time after menopause (more than 3 years usually)

Question 42

What are the negative effects of SERMs - selective oestrogen receptor modulators

Answer 42

Hot flushes if taken too close to menopause Increased clotting risk Lack of protection at the hip

Question 43

What is required for biphosphonates to be prescribed

Answer 43

adequate renal function and intake of calcium and vitamin D

Question 44

What are the side effects of biphosphonates

Answer 44

Oral bisphosphonates can cause heart burn and indigestion Iritis /Uveitis osteonecrosis of the jaw atypical femoral shaft fractures Drug holidays are given in between long spells of bisphosphonate treatments

Question 45

What is denosumab

Answer 45

Monoclonal antibody against RANK ligand which reduces osteoclastic bone resorption

Question 46

How often is denosumab given

Answer 46

injection every 6 months

Question 47

What is used in patients with significant renal impairment as treatment for osteoporosis

Answer 47

denosumab - safer than biphosphonates in patients with renal impairment

Question 48

What are the side effects of denosumab

Answer 48

Allergy/rash symptomatic hypoglycaemia if given to someone who has low Vitamin D Osteonecrosis of the jaw Atypical femoral shaft fractures

Question 49

What is teriparatide

Answer 49

Anabolic therapy which is a PTH analogue - reduces refracture rates

Question 50

What are the side effects of teriparatide

Answer 50

Injection site irritation Hypercalcaemia - rare Allergy Very expensive

Question 51

What is romosozumab

Answer 51

Monoclonal antibody which inhibits sclerotin It increases bone formation and decreases resorption

Question 52

How often is romosozumab given

Answer 52

Monthly injections

Question 53

What are the side effects of romosozumab

Answer 53

High risk of allergy - difficulty breathing, swelling, burning eyes, red/purple rash Severe symptoms - heart attack, stroke, chest pain and shortness of breath