Osteoporosis

Question 1

what type of disease is osteoporosis

Answer 1

progressive systemic skeletal disease

Question 2

what is osteoporosis characterised by

Answer 2

low bone mass and micro-architectural deterioration, with consequent increased bone fragility and susceptibility to fracture

Question 3

what are the main types of bone cells

Answer 3

osteoclasts, osteoblasts, osteocytes

Question 4

describe what an osteoclast is

Answer 4

multinucleated cells responsible for bone resorption, derived from haematopoietic progenitors

Question 5

describe what an osteoblast is

Answer 5

mononuclear cells derived from mesenchymal cells in the bone marrow stroma, responsible for bone formation

Question 6

describe what an osteocyte is

Answer 6

most common type and primary cell of mature bone, derived from osteoblasts thought to sense mechanical strain on skeleton

Question 7

what are bone remodelling units

Answer 7

distinct sites in the bone where it undergoes a continual remodelling cycle

Question 8

what regulating factors affect peak bone mass

Answer 8

genetics(70-80%), body weight, sex hormones, diet, exercise

Question 9

what regulating factors affect bone loss

Answer 9

sex hormone deficiency, body weight, genetics, diet, immobility, diseases, drugs(esp glucocorticoids)

Question 10

how many people in the UK are estimated to have osteoporosis

Answer 10

3 million

Question 11

describe the impact of osteoporotic fractures on patients lives

Answer 11

major cause of pain, disability, death, 50% hip fracture patients cannot live independantly

Question 12

what are common osteoporotic fracture sites

Answer 12

neck of femur, vertebral body, distal radius, humeral neck

Question 13

in what group of people do hip fractures most commonly occur

Answer 13

women >75y/o

Question 14

what are the guidelines for osteoporotic fractures based on

Answer 14

based around fracture risk not bone mineral density

Question 15

what are some non-modifiable clinical risk factors for fragility bone fractures

Answer 15

increased age, F>M, ethnicity, previous fracture, FH, menopause(<45yo), co-existing disease

Question 16

what are some modifiable clinical risk factors for fragility bone fractures

Answer 16

bone mineral density, alcohol, weight, smoking, physical inactivity, pharmacological risk factors

Question 17

what are the benefits of the WHO fracture risk calculator

Answer 17

allows calculation of absolute risk by using additional risk factors as well as bone mineral density, also 1o year prediction of major osteoporotic fracture

Question 18

who should be risk factor assessed for osteoporotic fractures

Answer 18

anyone >50 with any risk factors, <50 with very strong risk factors(eg early menopause, glucocorticoids)

Question 19

what’s the mainstay of bone mineral density assessment and when would a patient be referred for it

Answer 19

DEXA scans, anyone with 10 year risk assessment for any osteoporotic fractures of at least 10%, or >50 with low trauma fracture

Question 20

what is DEXA scan result for normal bone and for osteopenia

Answer 20

normal = BMD within 1 of young adult reference mean
osteopenia = BMD >1 but <2.5 below young adult reference mean

Question 21

what is the DEXA scan result for osteoporosis and severe osteoporosis

Answer 21

osteoporosis = BMD >/=2.5 below young adult mean
severe = BMD>/= below young adult mean with fragility fracture

Question 22

what are some secondary endocrine causes of osteoporosis

Answer 22

hyperthyroidism, hyperparathyroidism, Cushing’s disease

Question 23

what are some secondary non-endocrine causes of osteoporosis

Answer 23

coeliac disease, IBD, COPD, chronic kidney disease