Bone Diseases

Question 1

What is the PTH and calcium relationship?

Answer 1

Question 2

What is the Vitamin D cycle?

Answer 2

Skin turns sunlight to D3

Liver to 25 0Hd

Kidney to 1.25 0HD (calcitriol)

Question 3

What is osteoporosis?

Answer 3

A reduction in bone mass due to increased osteoclast activity

Question 4

What are the symptoms of osteoporosis?

Answer 4

None, until fracture occurs

Question 5

What are the common locations for osteoporosis related fractures?

Answer 5

Femur, wrist, vertebrae

Question 6

What are the metabolic/hormone risk factors for osteoporosis?

Answer 6

Hyperparathyroidism

Cushings - Cortisol suppresses osteoblasts

Menopause in women as oestrogen protective

Late menarche

Question 7

When does bone mass start to reduce?

Answer 7

After 40

Question 8

What are some other risk factors for osteoporosis?

Answer 8

Genetics

Low/High BMI

Question 9

What are some drug risk factors for osteoporosis?

Answer 9

SSRIs

Steroids

Chemo

Question 10

What are the investigations for osteoporosis and what are the values?

Answer 10

DEXA scan.

T <-2.1 is osteoporosis.

T<-1 - 2.1 is osteopenia

Question 11

What is the conservative management for osteoporosis?

Answer 11

Active lifestyle

Vit D and calcium supplements

Question 12

What is the drug management for osteoporosis - 2 classes and actions

Answer 12

Increase bone formation - Pulsatile PTH (teriparitide)

Decreasing bone resorption - Deriosiman (RankL inhibitor). Bisphosphonates (alendronic acid, zolendronic acid) inhibits osteoclasts

Question 13

What would blood tests show for osteoporosis?

Answer 13

Just increased bone resorption, not actual blood tests

Question 14

What is osteomalacia/Ricketts

Answer 14

Osteomalacia is adults and ricketts kids.

This is a lack of bone mineralisation due to low vitamin D

Question 15

What is the pathway for osteomalacia/ricketts?

Answer 15

Low vit D = Low Calcium = High PTH = increased bone resorption

Question 16

Why does osteomalacia lead to osteoporosis and what metabolic disorder does it lead to?

Answer 16

Low vit D = Low Calcium = High PTH = increased bone resorption

Secondary hyperparathyroidism

Question 17

What are the symptoms of osteomalacia/ricketts?

Answer 17

Bone pain and deformity

Fractures

Myopathy

Growth retardation

Question 18

What are the causes of osteomalacia/ricketts?

Answer 18

Low vit d due to low sun exposure

Malabsorption

Abnormal vit D metabolism due to liver/kidney disease

Question 19

What is the treatment for osteomalacia/ricketts?

Answer 19

Vit D supplements

Need the active form if the problem is in the liver of kidneys

Question 20

What would the urine show of someone with osteomalacia/ricketts?

Answer 20

Low calcium, high phosphate

Question 21

What would the blood show in someone osteomalacia/ricketts?

Answer 21

Low or normal calcium (secondary hyperparathyroidism)

Raised PTH

Low Vit D

Raised ALP

Question 22

What is Pagets Disease?

Answer 22

This is disordered bone metabolism with increased osteoclast activity and conpensatory increased osteoblast activity. This forms lots of woven bone

Question 23

What are the symptoms of Pagets Disease?

Answer 23

Usuall asymptomatic but can cause:

Bone pain

Bone deformities, eg facial bossing

Fractures

Neurovascular problems, eg deafness.

Question 24

What would investigations into Pagets disease show?

Answer 24

Increased ALP and Calcium

Normal PTH

Increased uptake on a bone scan

Question 25

What is this?

Answer 25

Pagets disease

Question 26

What is this

Answer 26

Facial bossing from Pagets

Question 27

What bloods would be raised in bony mets?

Answer 27

ALP, Phosphate, Calcium

Question 28

What would the blood tests show for the diseases?

PTH

Calcium

ALP

Phosphate

Answer 28

Osteoporosis - All normal

Osteomalacia - PTH Normal, Calcium low or normal, ALP high, phosphate low LOW VIT D

Pagets - PTH normal, calcium high, ALP very high, phosphate normal

Mets - ALL HIGH