Osteoporosis

Question 1

stats: how many women are affected by osteoporosis?

Answer 1

1 in 3

Question 2

stats: how many men are affected by osteoporosis?

Answer 2

1 in 12

Question 3

what structural changes occur in osteoporosis?

Answer 3

• decreased size of osteons
• thinning of trabeculae
• enlargement of Haversian and marrow spaces

Question 4

what are the risk factors of osteoporosis?

Answer 4

• genetic/gender
• lifestyle/nutritional
• medical conditions
• drugs
• previous fragility fracture

Question 5

what are lifestyle/nutritional risk factors for osteoporosis?

Answer 5

• smoking
• excess alcohol
• sedentary
• prolonged immobilisation

Question 6

what are some medical conditions that are risk factors for osteoporosis?

Answer 6

• anorexia nervosa
• rheumatoid arthritis
• early menopause <45
• primary hypogonadism
• secondary amenorrhoea for more than 1 year
• hyperthyroidism
  primary hyperparathyroidism
• multiple myeloma
• transplantation
• chronic
• cushing’s disease

Question 7

what drugs are a risk factor for osteoporosis?

Answer 7

• chronic corticosteroid therapy
• excessive thyroid therapy
• gonadotrophin releasing hormone agonist/antagonist
• anticoagulants
• anticonvulsants
• chemotherapy

Question 8

a previous wrist fracture is a risk factor that does what?

Answer 8

• doubles the risk of future hip fracture

- triples the risk of future vertebral fracture

Question 9

what are the non-modifiable risk factors for osteoporosis?

Answer 9

• gender/biological sex
• age
• previous fracture
• family history
• long term steroid therapy
• race

Question 10

what are modifiable risk factors for osteoporosis?

Answer 10

• oestrogen deficiency
• smoking
• alcohol
• low calcium
• low BMI
• vitamin D deficiency
• inactivity

Question 11

what is type 1 osteoporosis?

Answer 11

post menopausal:

• affects mainly cancellous bone
• vertebral and distal radius fracture is common
• related to loss of oestrogen
• F:M=6:1

Question 12

what is type 2 osteoporosis?

Answer 12

age related >75:

• affects cancellous and cortical bone
• is related to poor calcium absorption
• hip and pelvic fractures common
• F:M=2:1

Question 13

where are common sites for osteoporotic fractures?

Answer 13

• distal radius
• neck of femur
• vertebral body
• proximal humerus
• spine

Question 14

what diagnostic investigations can be carried out for osteoporosis?

Answer 14

• blood tests
• FBC
• serum biochemistry
• bone profile
• thyroid function tests
• testosterone and gonadotrophin levels in men
• x-rays
• bone mineral density measurement
• DEXA scan

Question 15

what is a DEXA scan?

Answer 15

dual-energy x-ray absorptiometry scan:
-low dose x-rays with two distinct energy peaks (subtracting one from another gives patient’s bone mineral density (BMD))

Question 16

what are treatment methods for osteoporosis?

Answer 16

• bisphosphonates
• anabolic agents
• ca2+ supplements
• hormone replacement therapy
• increase exercise

Question 17

what is the function of osteoprogenitor cells?

Answer 17

• stem cells population

- gives rise to osetoblasts

Question 18

what is the function of osteoblasts?

Answer 18

• responsible for bone formation

- cover the surface of bone

Question 19

what is the function of osteocytes?

Answer 19

• mature bone cells
• embedded in lacunae
• relatively inactive
• maintain bone matrix through cell-to-cell communication
• influence bone remodelling
• mechanosensing

Question 20

what is the role of osteoclasts?

Answer 20

• multinucleated
• derived from haematopoietic cells
• in response to mechanical stresses and physiological demands they resorb bone matrix by demineralisation

Question 21

what is the relationship between chronic corticosteroid therapy and osteoporosis?

Answer 21

can increase risk of fracture by 2-3x

Question 22

what is disuse osteoporosis?

Answer 22

conditions resulting in prolonged immobilisation, typically in neurological or muscle disease

Question 23

what is a fragility fracture?

Answer 23

• “low energy” trauma
• mechanical forces that would not ordinarily cause fracture
• WHO: “fall from standing height or less”

Question 24

what percentage of hip fracture cases are fatal?

Answer 24

20-30%

Question 25

what percentage of those with hip fractures fully recover?

Answer 25

30%

Question 26

what percentage of those with hip fractures are left permanently disabled?

Answer 26

50%

Question 27

what percentage of bone loss must there be for it to be visible on x-ray?

Answer 27

> 30%

Question 28

what are the DEXA T score values and meanings?

Answer 28

> -1 : normal

-1 to - 2.5 : osteopenia (bone thinning)

< - 2.5 : osteoporosis

Question 29

what is the DEXA Z score?

Answer 29

comparison of the patients’s BMD with data from same age/sex/size

Question 30

what are examples of bisphosphonates used in treatment of osteoporosis?

Answer 30

• alendronate

- risedronate

Question 31

how are bisphosphonates used to treat osteoporosis?

Answer 31

disrupt osteoclast activity

Question 32

what are potential side effects of bisphosphonates treatments?

Answer 32

• oesophagitis

- mandibular necrosis

Question 33

what are examples of anabolic agents used to treat osteoporosis?

Answer 33

• intermittent PTH

- strontium ranelate