bone disorders

Question 1

what is active bone resorption driven by

Answer 1

osteoclasts

Question 2

what is bone formation driven by

Answer 2

osteoblasts

Question 3

what is bone like at 50 years

Answer 3

Decrease in trabecular thickness which is more pronounced for non load-bearing horizontal trabeculae

Question 4

what is bone like at 80 years

Answer 4

• Decrease in number of connections between vertical trabeculae
• Decrease in trabecular strength

Question 5

what factors affect bone loss

Answer 5

• sex hormone deficiency
• body weight
• genetics
• diet
• immobility
• diseases
• drugs

Question 6

what are some modifiable risk factors for fractures

Answer 6

• BMD
• alcohol
• weight
• smoking
• physical inactivity
• pharmacological risk factors

Question 7

who is assessed for fracture risk

Answer 7

• anyone over 50 with risk factors

- anyone under 50 with very strong clinical risk (early menopause and glucocorticoids)

Question 8

what defines osteopenia

Answer 8

BMD >1 SD below the young adult mean but <2.5 SD below this value

Question 9

what defines osteoporosis

Answer 9

BMD ≥ 2.5 SD below the young adult mean

Question 10

what defines severe osteoporosis

Answer 10

BMD ≥2.5 SD below the young adult mean with fragility fracture

Question 11

secondary causes of bone disease

Answer 11

• Endocrine e.g. hyperthyroidism, hyperparathyroidism, Cushing’s disease
• Gastrointestinal e.g. coeliac disease, IBD, chronic liver disease, chronic pancreatitis
• Respiratory e.g. CF, COPD
• Chronic kidney disease

Question 12

drug treatments for osteoporosis

Answer 12

• Calcium & vitamin D supplementation
• Bisphosphonates
• Denosumab
• Teriparatide
• Romosozumab
• HRT
• SERMS (Selective Estrogen Receptor Modulators)
• Testosterone

Question 13

what do bisphosphonates do

Answer 13

mainstay of treatment for osteoporosis

• prevent bone loss at all sites vulnerable to osteoporosis
• anti-resorptive agents
• injested by osteoclasts leading to cell death thereby inhibiting bone resorption

Question 14

when is treatment considered with antiresorptive therapy

Answer 14

when T score is

Question 15

how is zoledronic acid given

Answer 15

once yearly IV infusion for 3 years

-second line to bisphosphonates

Question 16

what does denosumab

Answer 16

fully human monoclonal antibody that targets and binds with high affinity and specificity to RANKL
-This prevents activation of its receptor, RANK, inhibiting development and activity of osteoclasts, decreasing bone resorption and increasing bone density.

Question 17

how is denosumab given

Answer 17

subcutaneous injection 6 monthly

Question 18

what does teriparatide do

Answer 18

stimulates bone growth rather than reducing bone loss

-restricted to patients with severe osteoporosis as very expensive

Question 19

what does romosozumab do

Answer 19

a monoclonal antibody that binds to and inhibits sclerostin

• increases bone formation and reduced bone resorption
• for postmenopausal women

Question 20

what are corticosteroids effect on bone

Answer 20

• direct reduction of osteoblast activity and lifespan
• direct suppression of replication of osteoblast precursors
• direct reduction in calcium absorption
• indirect inhibition of gonadal and adrenal steroid production

Question 21

what is Paget’s disease

Answer 21

• abnormal osteoclastic activity followed by increased osteoblastic activity
• abnormal bone structure with reduced strength and increased fracture risk

Question 22

what does paget’s disease present with

Answer 22

• bone pain
• deformity
• deafness
• compression neuropathies

Question 23

diagnosis of paget’s

Answer 23

Diagnose on XR; isotope bone scan shows the distribution of disease; biochemistry shows raised alkaline phosphatase with otherwise normal LFTs

Question 24

treatment of paget’s disease

Answer 24

bisphophonates if pain not responding to analgesia