Osteoporosis

Question 1

Definition

Answer 1

• Reduced bone density/ low bone mass.

- Structural defects in bone tissue increasing its fragility and susceptibility to fracture.

Question 2

Epidemiology

Answer 2

• White
• Post-menopausal (Less oestrogen)= less OPG= overexpression of RANKL
• Women
• Elderly

Question 3

Pathophysiology

Answer 3

Decreased bone mineral density due to

• Low peak bone mass
• Loss of bone mass due to ageing or disease states/ drugs

Poor shape/ micro-architrecture
- Unbalance bone resorption and formation between osteoclasts and osteoblast

Question 4

Roles of osteoclasts and osteoblasts in bone formation

Answer 4

Osteoclasts- bone resorption of bone matrix via forming resorption pits

• RANK
• TNF

Osteoblasts

• Bone formation by laying down bone matrix
• RANKL
• OPG (inhibits RANKL activation)= less resorption

Question 5

Investigations for Osteoporosis

Answer 5

Imaging

• DEXA= bone density measurement. = -2.5 is osteoporosis
• -1.5- (-2.5)= osteopenia
• Ultrasound of heel for done density
• X-ray of wrist, spine, hip= identifies fractures and indication for DEXA

Bloods

• LFT: ALP, albumin can indicate osteomalacia
• Serum Calcium, Phosphate, Vit D, PTH
• TFT: rule out hyperthyroidism
• Testosterone: rule out hypoandrogenism cause.

Question 6

Osteoporosis first line treatment

Answer 6

Bisphosphonates

• Alendronate
• Zolendronate (IV)
• Risedronae
• Ibandronic acid

Vit.D and Calcium supplements
- Prevents risk of fracture

Question 7

Osteoporosis second line treatment

Answer 7

Raloxifene (SERM)
- Binds to selective oestrogen receptors nd promotes bone formation

Denosumab (MnAb)
- Inhibits RANKL= inhibits bone resorption

Question 8

Osteoporosis third line treatment (if first and second isn’t tolerated)

Answer 8

Teriparatide

• PTH like molecule
• Promotes bone formation by acting on osteoblasts

Question 9

Primary prevention of osteoporosis

Answer 9

Prevents incidence of osteoporosis and first fracture.

• Diet with Vit.D and calcium supplements
• Bisphosphonates (Oral) in those with longer term corticosteroid use
• Raloxifene in women with osteopenia

Question 10

Secondary prevention of osteoporosis

Answer 10

Prevents falls which prevents further fracture risk

• Hip protectors
• Physio/OT= gait and balance
• Weight bearing exercise
• Smoking and excess alcohol cessation

Question 11

Factors that increase osteoporosis risk

Answer 11

Disease states

• Hyperparathyroid
• Hyperthyroid
• Hypoandrogenism

Drugs

• long term heparin use
• Long term corticosteroid use
• Cyclosporin
• Kidney failure

Low weight

Excessive alcohol consumption

Immobility

Smoking