Osteoporosis

Question 1

What is osteoporosis?

Answer 1

● Reduced bone density (defined as > 2.5 standard deviations below peak bone mass achieved by healthy adults of that age and gender (i.e. T-score > 2.5)) resulting in bone fragility and increased fracture risk
● There is reduced bone mass

Question 2

What are the causes of osteoporosis?

Answer 2

Primary osteoporosis is bone loss that occurs during the normal human aging process. Secondary osteoporosis is defined as bone loss that results from specific, well-defined clinical disorders

1. Primary Osteoporosis (most common) → postmenopausal osteoporosis (decreased oestrogen leads to increased bone resorption due to increased osteoclast activity), senile osteoporosis (gradual loss of bone mass as patients age), rheumatoid arthritis
   - (Oestrogen stimulates osteoblasts and inhibits osteoclasts hence has protective role on bone strength)
   - Osteoporosis in a man ⇒ check testosterone
2. Secondary Osteoporosis → drug induced (long term corticosteroid therapy, or anticonvulsants, anticoagulants, PPIs), hypogonadism, hyperthyroidism, cushings syndrome, immobilisation, hyperparathyroidism, thin

Question 3

Describe the epidemiology of osteoporosis

Answer 3

F>M (4:1), age of onset 50-70 yrs old

Question 4

What are the risk factors for osteoporosis?

Answer 4

Osteoporosis risk factors can be remembered by the mnemonic SHATTERED FAMILY:

S – Steroid use
H – Hyperthyroidism, hyperparathyroidism
A – Alcohol and smoking
T – Thin (BMI<22)
T – Testosterone deficiency
E – Early menopause
R – Renal/liver failure
E – Erosive/inflammatory bone disease
D – Diabetes
FAMILY HISTORY

Question 5

What are the presenting symptoms of osetoporosis?

Answer 5

• Usually asymptomatic until fracture occurs
• Fragility Fractures → pathological fractures caused by everyday-activities or minor trauma
• Back Pain → Vertebral fracture is most common
• Thoracic kyphosis ( excessive forward curvature of the spine in the upper back) due to multiple vertebral fractures.

Question 6

What investigations are used to diagnose/ manage osteoporosis?

Answer 6

1. DEXA → gold standard for measurement of bone density. T-score ≤-2.5 indicates osteoporosis. (Osteopenia = -1 to -2.5)
   - T-Score = bone density as a standard deviation compared to reference population of healthy young adults (ie. -2.5 = 2.5 SD’s below that of an average healthy young adult)
   - Z-Score = adjusts for age, gender and ethnicity
2. X-Ray (wrist, heel, spine, hip)
   - X-Ray Spine ⇒ first line investigation for suspected osteoporotic vertebral fracture (NOT MRI)
3. FRAX → estimates 10 year risk of fragility fracture
4. Normal Bone Profile + Bloods (ALP, Ca, PO4, PTH)

Question 7

How is osetoporosis managed?

Answer 7

1. Bisphosphonates (Alendronate) → inhibit osteoclasts leading to reduced bone resorption. If patients can’t tolerate alendronate (due to upper GI side effects), give risedronate. Alendronic acid is another option
   ⇒ have side effect of dyspepsia and reflux due to oesophageal reactions (oesophagitis). Patients should take tablet on empty stomach 30 mins before breakfast with lots of water and remain upright for 30 mins after to reduce mucosal irritation. Can also cause osteonecrosis of the jaw.
   - Can also be used for hypercalcaemia, pagets disease and pain from bone metastases
2. Denosumab: Denosumab acts by inhibiting RANKL, which is responsible for the activation and development of osteoclasts that lead to the breakdown of bone.→ 2nd line treatment for postmenopausal women with osteoporosis
3. Calcium and Vitamin D supplementation (Ergocalciferol)
4. Teriparatide → PTH analogue
5. Avoid or minimise use of glucocorticoids

Question 8

What complications may arise from osetoporosis?

Answer 8

fractures (hip, rib, wrist)