1 - Bone disease

Question 1

Define arthritis.

Answer 1

Inflammation of joints

Question 2

Define arthrosis.

Answer 2

Non-inflammatory joint disease

Question 3

Define arthralgia.

Answer 3

Joint pain

Question 4

Describe bone.

Answer 4

• mineralised connective tissue
• load bearing
• dynamic (constantly remodelling and self repairing)
• requires calcium, phosphate and vit D to repair

Question 5

How do bone and calcium interact?

Answer 5

• if systemic calcium is low, bone will resorb to release calcium into blood
• caused by an increase in parathyroid hormone

Question 6

Describe PTH and its relationship to calcium.

Answer 6

• maintains serum calcium levels
• increased secretion of PTH if calcium low
• increases calcium release from bone
• decreases renal calcium excretion

Question 7

What is primary hyperparathyroidism and what is its effect?

Answer 7

• gland dysfunction (often caused by a tumour)
• increased secretion of PTH
• inappropriate activation of osteoclasts
• increased bone resorption

Question 8

What is secondary hyperparathyroidism and what is its effect?

Answer 8

• low serum calcium triggers
• increased secretion of PTH
• appropriate activation of osteoclasts
• regulates serum calcium

Question 9

What are causes of low vit D?

Answer 9

• low sunlight exposure (housebound or dark skinned in a northern country)
• poor GI absorption
• drug interactions (anti-epileptics)

Question 10

Define osteomalacia.

Answer 10

• normal amount of formation of bone
• poorly mineralised osteoid matrix and cartilage plate
• bone is pliable and soft

Question 11

Define osteoporosis.

Answer 11

• mineralisation and matrix formation are correct but there is reduced quantity
• reduced bone mass

Question 12

What is rickets?

Answer 12

Osetomalacia that occurs during bone formation

Question 13

How does osteomalacia affect the bone?

Answer 13

• legs bow (children)
• vertebral compression (adults)
• bones ache to touch

Question 14

What are the symptoms of hypocalcaemia?

Answer 14

• muscle weakness
• carpal muscle spasm
• facial twitching when VII tapped

Question 15

How does osteomalacia present in blood tests?

Answer 15

• decreased serum calcium
• decreased serum phosphate
• alkaline phosphatase very high (bone turnover)
• plasma creatine increased (if renal cause)
• plasma PTH increased (if 2y hyperparathyroidism)

Question 16

How do you manage osteomalacia?

Answer 16

• correct malnutrition (address if GI cause)
• sunlight exposure 5x30mins weekly
• vit D supplement

Question 17

What are the risk factors for osteoporosis?

Answer 17

• age
• F > M
• endocrine (oestrogen/testosterone deficiency, Cushings syndrome)
• genetic (FH, race, early menopause)
• patient factors (inactive, smoking, alcohol, poor diet)
• drugs (anti-epileptic, steroids)

Question 18

At what age is peak bone mass?

Answer 18

24-35 years

Question 19

Why is osteoporosis more common in women?

Answer 19

• males have higher peak bone mass than women
• oestrogen withdrawal (menopause) increase bone mass loss rate

Question 20

What are the effects of osteoporosis?

Answer 20

• long bone fracture (femurs, wrists, hip fracture)
• height loss
• kyphosis (bending forward)
• scoliosis (lateral shifting of vertebrae)
• nerve root compression (back pain)

Question 21

How can you prevent osteoporosis?

Answer 21

• build maximal peak bone mass (high calcium diet, exercise)
• reduce rate of bone mass loss (continue with exercise and calcium in diet, HRT, bisphosphonates)

Question 22

Describe HRT in relation to osteoporosis.

Answer 22

• most effective during early menopause
• loses effect 5 years after stopping
• increased breast, endometrium, ovarian cancer risk
• increased DVT risk

Question 23

What are bisphosphonates?

Answer 23

• drugs that act to reduced osteoclast activity by poisoning them
• reduced osteoclasts = reduced bone loss

Question 24

What bisphospohonates are commonly used?

Answer 24

• alendronate
• ibandronate
• zoledroante (most potent, given once a year)