PBL 1

Question 1

How many fractures a year does osteoporosis cause

Answer 1

8.9 million fractures annually

Question 2

how many fractures does osteoporosis cause in the UK

Answer 2

200,000

- costs £1.73 bn

Question 3

describe the rise in prevalence of osteoporosis

Answer 3

• 10% of those over 60 years old
• 20% of those over 70 years old
• 40% of those over 80 years old
• 65% of those over 90 years old

Question 4

what is the risk of osteoporotic fractures greater than

Answer 4

Risk of osteoporotic fractures in 1 year is greater than the combined risk of heart attack, stroke and breast cancer

Question 5

what are the causes of osteomalacia

Answer 5

• vitamin D deficiency
• deficient sun exposure and vitamin D intake
• celiac disease
• hypophosphoatemic osteomalacia
• x linked
• bariatric surgery

Question 6

What are the causes of osteoporosis

Answer 6

• menopause
• smoking
• diet
• emotional stress
• excessive alcohol use
• medication

Question 7

what are the risk factors for osteoporosis

Answer 7

female

smoking

poor nutrition

malabsorption

low oestrogen levels

Question 8

what does Terrance results show

Answer 8

• shows a decrease in vitamin D (25-OHD) this shows that osteomalacia is present
• calcium is normal
• phosphate is normal
• alkaline phosphatase is high
• parathyroid is normal
• the normal results show that osteoporosis is present

Question 9

What does terrance have

Answer 9

• he has a mixture of osteoporosis and osteomalacia

Question 10

what is the difference between osteoporosis and osteomalacia

Answer 10

Osteoporosis

• the ratio between unminerliased and mineralised remains the same but the amount of bone decreases
• this is because the osteoblasts are not producing more bone but osteoclasts are reabsorbing the bone
• everything remains normal
• biomarkers present is cathepsin K, C-telopeptide

Osteomalacia

• the amount of unmineralised bone increased in comparison to osteoporosis
• has low vitamin D
• low calcium
• low phosphate
• high PTH
• high ALP
• biomarter is osteocaltin

Question 11

what is osteoporosis

Answer 11

Osteoporosis is a complex disorder characterised by an imbalance in the bone remodelling process, which is governed by intricate interactions between various hormones, cytokines and a novel regulatory system

Question 12

What is the treatment of osteomalacia

Answer 12

• If they have a liver or kidney problem you may need to take vitamin D supplements for the rest of your life
• Dietary – increase calcium = calcium is found in milk, bread, beans and pulses, dried fruit and green leafy vegetables
• Sun or UV exposure = 15 minutes of sun on hands and face 2-3 times a week in spring and summer is sufficient

Question 13

What is the treatment plan for osteoporosis

Answer 13

• if they are over 75 and have a low trauma fracture then start the patient on bisphosphonate, calcium and vitamin d
• if they are between the age of 50-75 and have had a low trauma fracture refer for a dexa scan

Dexa scan results

• aged 50-65, and the T score is less than -3.2 then start on bisphosphonate, calcium and vitamin D
• if aged 50-65 and the T score is between -2.5 and -3.2 and there is a clinical risk factor then start on bisphosphonate, calcium and vitamin d
• if aged 50-75, and the T score is greater than -2.5, start on calcium and vitamin D
• if age 65-75, and T score is less than -2.5 then start on bisphosphonate, calcium and vitamin d

Question 14

name two other medication you can take for osteoporosis

Answer 14

• Teriparatide = Intermittent exposure to PTH will activate osteoblasts more than osteoclasts therefore increasing the amount of bone production compared to bone reabsorption
• Denosumab = antibody that binds to RANKL preventing the activation of osteoclasts therefore reducing bone reabsorption, giving as a subcutaneous injection every 6 months

Question 15

What are problems with bisphosphonate

Answer 15

• Giant osteoclasts
• Osteonecrosis of the jaw
• Atypical fractures

Question 16

How does bisphosphonate work

Answer 16

• inhibit osteoclast activity by preventing the osteoclasts from binding to the bone and promote osteoclast apoptosis
• increase OPG and decrease RANKL

Question 17

what are the type of surgical management of the neck of the femur fracture

Answer 17

• intramedullary nail
• cannulated screws
• compression screws
• hemlarthroplasty

Question 18

What is a physician associate

Answer 18

Physician associates support doctors in the diagnosis and management of patients. As a physician associate, you might work in a GP surgery or be based in a hospital

Question 19

why is a DEXA scan used to measure bone mineral density

Answer 19

DEXA scans use two low energy x-rays beams (1 mark) this increases the sensitivity of the scan in measuring bone density (1 mark)

Question 20

What type of bone is most susceptible to developing osteoporosis and explain why?
2 marks

Answer 20

Trabeculae bone 1 mark

Because it turns over quicker and more often than cortical bone.

Question 21

Assuming that the vitamin D supplement is un- hydroxylated. State how and where it is converted to the most bioactive di-hydroxylated version in the body. You do no need to name the enzymes involved.
2 marks

Answer 21

First it is converted into 25 hydroxyl vitamin D in the liver. 1 mark This is converted in the kidney into the 1,25 dihydroxy vitamin D 1 mark

Question 22

What is the usual age related bone loss per year for a man? 1 mark

Answer 22

1-2% per year

Question 23

Explain why a patient with kidney problems is at higher risk of osteomalacia

Answer 23

The 1alpha hydroxylase that adds the seconf hydroxyl unit onto vitamin D is in the kidney. So kidney failure means that there is less of the active 1,25 dihydroxy vitamin D in the body.