metabolic bone disease

Question 1

what is the role of osteoclasts

Answer 1

to break down bone

Question 2

what is the role of osteoblasts

Answer 2

to build up bone

Question 3

where is vitamin D produced

Answer 3

by the skin

Question 4

where is vitamin D stored

Answer 4

in the liver

Question 5

where is vitamin D activated

Answer 5

at the kidneys

Question 6

what is the name of the vitamin D that has been activated by the kidneys

Answer 6

calcitrol

Question 7

what is the role of calciferol

Answer 7

to increase the amount of calcium that is absorbed from the gut

Question 8

what will happen is there is a calcium or vitamin D deficiency in children

Answer 8

rickets

Question 9

what will happen if there is a calcium or vitamin D deficiency in adults

Answer 9

osteomalacia

Question 10

what is the difference between rickets and osteomalacia

Answer 10

fusion of the epiphyseal plates

Question 11

name some clinical signs of rickets

Answer 11

• stunted growth
• large abdomen
• large forehead
• bent out legs
• wide bones and joints

Question 12

what is the cause of rickets

Answer 12

a deficiency in calcium or vitamin D in children

Question 13

what is Paget’s disease

Answer 13

this is a disorder in which there is too much bone resorption and formation which leads to the formation of disordered bone

Question 14

what is the treatment of rickets and osteomalacia

Answer 14

increased intake of calcium and vitamin D (if there is kidney failure you may need to give the patient activated vitamin D)

Question 15

where is the mutation in Paget’s

Answer 15

on the loci of SQSTMI

Question 16

what proportion of Paget’s is familial

Answer 16

15-30%

Question 17

what are the symptoms of Paget’s disease

Answer 17

• long history of bone pain
• bone deformity
• excessive heat over the affected bone
• neurological problems (e.g. hearing loss) - Paget’s can occur in the skull bones
• may present with an osteosarcoma

Question 18

what serum test will be raised in those with Paget’s

Answer 18

alkaline phosphatase

Question 19

what is the treatment of Paget’s disease

Answer 19

SHOULD NOT BE TREATED IF ASYMPTOMATIC UNLESS IN THE SKULL

• IV bisphosphonate

Question 20

what is osteogenesis imperfecta

Answer 20

this is a genetic disorder characterised by fragile bones - there are different types and prognosis depends on the type

Question 21

what are the different types of osteogenesis imperfect

Answer 21

Type 1 = mild and potentially a few fractures
Type 2 = this is the most severe form and children usually die within weeks of being diagnosed
Type 3 = progressive deformity and bone dysplasia however not as severe as type 2
Type 4 = similar to type 1 but more severe

Question 22

what are the clinical signs of osteogenesis imperfecta

Answer 22

• blue sclera
• scoliosis
• barrel chest
• defective tooth formation
• hearing loss
• ligamentous laxity

Question 23

what is the management of osteogenesis imperfecta

Answer 23

• IV bisphosphonates
• surgery to repair fractures
• social adaptations
• genetic counselling

Question 24

what is osteoporosis

Answer 24

this is a bone disease that is characterised by low bone mass and micro architectural deterioration - enhances bone fragility and fracture risk

Question 25

what investigation can be used to diagnose osteoporosis

Answer 25

a bone DXA scan - a score of -2.5 SD or more from the normal adult healthy mean in post-menopausal woman those with a score of -2.5 or more should be offered treatment and those with a score between -1 and -2.5 should be offered lifestyle advice (unless they have had a previous fracture - they should be offered treatment in this case)

Question 26

when should someone be referred for a DXA scan

Answer 26

if they have a fracture risk assessment score of more than 10%

Question 27

name the WHO fracture risk assessment tool

Answer 27

FRAX

Question 28

name the fracture risk assessment tool that is most commonly used in Scotland

Answer 28

Q fracture risk assessment

Question 29

name some conditions that can cause secondary osteoporosis

Answer 29

- bushings - hyperthyroidism - hyperparathyroidism - hypoparathyroidism - coeliac disease - cystic fibrosis - steroids, heparin and warfarin

Question 30

how can you minimise someones osteoporotic fractures

Answer 30

- ensure good calcium and vitamin D status - medications - fall prevention strategies - minimise the risk factors if possible

Question 31

name the different types of medications that are used in the management of osteoporosis

Answer 31

- hormone replacement therapy - selective oestrogen receptor modulator - bisphosphonates - teriparatide - denosumab

Question 32

what is the benefit of using hormone replacement therapy

Answer 32

it is effective on all bones

Question 33

what are the side effects of hormone replacement therapy

Answer 33

- increased risk of blood clots - increased risk of heart disease and stroke - increased risk of breast cancer SHOULD NOT BE USED A LONG TIME AFTER MENOPAUSE

Question 34

what are the side effects of using selective oestrogen receptor modulators

Answer 34

- only works on vertebrae - increased risk of blood clotting - hot flushes if taken to close to menopause

Question 35

what is the main treatment used in the management of osteoporosis

Answer 35

oral bisphosphonates

Question 36

what are the side effects of using bisphosphonates

Answer 36

- oesphagitis - uveitis - femoral shaft fractures - osteonecrosis of the jaw - must have good renal function - must have good calcium/vit D status - drug holiday of 1-2 years needed after every 10 years

Question 37

how do bisphosphonates work

Answer 37

bisphosphonates inhibit the osteoclasts and therefore prevent the breakdown of bone

Question 38

what is teriparatide

Answer 38

this is an injection that works by building the bone up (this is the only anabolic treatment for osteoporosis)

Question 39

what are the side effects of using teriparatide

Answer 39

- injection site reaction - allergy - cost - hypercalcaemia

Question 40

what is denosumab

Answer 40

a subcutaneous injection given every 6 months that reduces osteoclast bone resorption this drug targets RANKL which usually inhibits the osteoblasts

Question 41

what are the side effects of denosumab

Answer 41

- allergy - hypocalcaemia - osteonecrosis of the jaw - atypical femoral shaft fractures