Osteoporosis

Question 1

Definiton

Answer 1

A condition of skeletal fragility characterised by reduced bone mass and micro architectural deterioration predisposing a person to increased fracture risk.

Question 2

Epidemiology

Answer 2

• Most common bone disorder
• women > men
• caucasians
• Signficant cause of disability and morbidity

Question 3

Pathogeneis of osteoporosis

Answer 3

2 mechanisms:

• failure to reach peak bone mass
  
  • genetics
  • exercise
  • calcium intake
• accelerated bone loss:
  
  • increased bone resorption
  • reduction in bone formation
  • imbalance of osteoclast and osteoblast activity
  • resorption > formation

Question 4

Risk factors

Answer 4

ACCESS

A- alcohol use/ Increasing age

C- Corticosteroid use

C- calcium low

E- oestrogen low

Smoking

Sedentary lifestyle

Question 5

Secondary causes

Answer 5

• endocrine: hyperthyroidism, hyperparathyroidism, hypogonadism, Cushings
• Inflammatory: IBD, RA, Akylosing spondylitis
• Gastrointestinal: malabsoprtion, CLD
• Respiratory: COPD, cystic fibrosis
• Miscellaneous: myeloma, anorexia, HIV, immobilisation
• Drugs: as before

Question 6

Clinical features

Answer 6

• often asymptomatic
• Fragility fractures
  
  • wrist
  • hip
  • Spine- thoracic kyphosis
• underlying disease features if secondary OP

Question 7

Investigation and diagnosis

Answer 7

Bloods

• Bone profile
• Myeloma screen
• Renal function and LFTs
• Vitamin D
• Thyroid function
• Bone turnover markers

X-ray

• Fragility fractures
• Thoracic kyphosis

DEXA

• Between -1.0 and -2.5 -osteopenia
• < -2.5 - osteoporosis

Question 8

Indications for DEXA

Answer 8

• low trauma fracture, age >50
• clinical features of OP (kyphosis, height loss)
• Osteopenia on X-ray
• corticosteroid therapy
• FH of hip fracture
• Low BMI <18
• Early menopause <45
• disease associated with OP
• Assessing response of OP to treatment

Question 9

Treatment- lifestyle modificaitons

Answer 9

• Calcium and vitamin D intake
• Weight bearing exercise
  
  • Improves bone density
  • Reduces falls risk
• Stop smoking
• Reduce alcohol
• Hip protection

Question 10

Treatment -pharmacological

Answer 10

• Calcium/Vitamin D replacment
• Bisphosphonates - inhibit bone resorption
• strontium ranelate- inhibits bone resorption/stimulates bone formation
• Synthetic PTH (teriparatide) - stimulates bone formation
• SERMS (ralofoxone, tibolone)- stimulates bone formation
• HRT- indicated for OP in early menopausal women
• Denosumab (MAB against RANKL