Biochemistry

Question 1

What is a quantitative bone defect?

Answer 1

When there is sufficient bone quality, but not enough is present.

Question 2

What is a qualitative bone defect?

Answer 2

When there is sufficient bone quantity, but it is not of the required quality.

Question 3

What is osteoporosis?

Answer 3

A quantitative bone defect characterised by decreased density, and increased porosity.

Defined as being >2.5 standard deviations BELOW the young adult peak.

Question 4

What is a consequence of osteoporosis?

Answer 4

Increased fracture risk.

May occur with minimal trauma.

Question 5

What is osteopenia?

Answer 5

A bone mass density between 1-2.5 standard deviations BELOW the young adult peak.

Question 6

Can bone density loss be normal?

Answer 6

Yes, it is lost physiologically with age.

Most noticeable in women following menopause (as no effects of oestrogen remains within the system).

Question 7

How is osteoporosis diagnosed?

Answer 7

DEXA scan

Remember to compare BMD to that of a young adult of the same race and gender.

Question 8

Can osteoporosis be cured?

Answer 8

No, the aim of treatment is to prevent progression, and minimise risk of fracture.

Question 9

How can risk of fracture be reduced in those with osteoporosis?

Answer 9

Healthy diet
Good exposure to sunlight
Vitamin D supplements
Calcium supplements
Bisphosphonates

Question 10

What is a potential side-effect of both HRT and raloxifene?

Answer 10

DVT

Question 11

Aside from bisphosphonates, what may be used to treat osteoporosis?

Answer 11

Desunomab
Strontium
Zoledronic acid
HRT
Raloxifene

Question 12

By which mechanism do bisphosphonates help in osteoporosis?

Answer 12

Reduces osteoclastic function.

This is the first-line form of treatment.

Question 13

By which mechanism does desunomab help in osteoporosis?

Answer 13

Reduces osteoclast activity.

A form of monoclonal antibody.

Question 14

What form of drug is zoledronic acid?

Answer 14

Bisphosphonate - this type is given once yearly.

Question 15

What is osteomalacia?

Answer 15

A qualitative defect which results from abnormal bone softening.

The result of deficiencies in bone mineralisation.

Question 16

What is osteomalacia called in children?

Answer 16

Rickett’s

Question 17

What is thought to be responsible for osteomalacia/Rickett’s development?

Answer 17

Insufficient absorption of calcium, or a deficiency of vitamin D.

Question 18

How does osteomalacia/Rickett’s present?

Answer 18

Bone pain
Soft bone deformities
Features of hypocalcaemia

Question 19

What are features of hypocalcaemia?

Answer 19

Bone pain
Renal stones
Abdominal groans
Psychiatric moans

Question 20

How does osteomalacia/Rickett’s impact blood tests?

Answer 20

Low calcium
Low phosphates
High ALP

Question 21

How is osteomalacia/Rickett’s treated?

Answer 21

Vitamin D supps
Calcium supps
Phosphate supps

Question 22

What is hyperparathyroidism?

Answer 22

Overactivity of the parathyroid glands.

Will lead to high PTH levels, high calcium, and normal/low phosphate levels.

Question 23

What may cause primary hyperparathyroidism?

Answer 23

Benign adenoma
Hyperplasia
Malignancy

Question 24

What may be responsible for secondary hyperparathyroidism?

Answer 24

A physiological overproduction of PTH
Vitamin D deficiency
Chronic kidney disease

Question 25

How are very high calcium levels treated?

Answer 25

IV fluids Bisphosphonates Calcitonin

Question 26

What is renal dystrophy?

Answer 26

Bone changes observed in those with chronic kidney disease.

Question 27

How does chronic kidney disease affect bone?

Answer 27

There will be reduced phosphate excretion and inactivation of vitamin D, resulting in secondary hyperparathyroidism. This produces osteomalacia, sclerosis of bone, and the calcification of soft tissues.

Question 28

What is Paget's disease?

Answer 28

A chronic bone disorder that produces thickened, mis-shapen, brittle bones. It is the result of increased bone turnover.

Question 29

Where does Paget's disease commonly affect?

Answer 29

Pelvis Skull Femur Tibia Ear ossicles

Question 30

How does Paget's disease affect blood results?

Answer 30

Normal calcium Normal phosphates Raised ALP

Question 31

How should Paget's disease be treated?

Answer 31

Give bisphosphonates Manage any pathological fractures with IM nails/plating. Some may need joint replacement.

Question 32

What diagnosis is indicated by a normal calcium, normal phosphate, normal ALP and normal PTH levels?

Answer 32

Osteoporosis Osteopetrosis

Question 33

Low calcium, low phosphate, raised ALP, and raised PTH levels are indicative of which diagnosis?

Answer 33

Primary hyperparathyroidism

Question 34

Reduced calcium, normal phosphate, normal PTH, and raised PTH levels are indicative of which diagnosis?

Answer 34

Chronic Kidney Disease Secondary Hyperparathyroidism

Question 35

Normal calcium, normal phosphate, raised ALP, and normal PTH levels are indicative of what?

Answer 35

Paget's disease