Osteoporosis & Fragility Fractures

Osteoporosis is a systemic skeletal disease of low bone mass and microarchitectural deterioration that increases bone fragility and fracture risk, defined on DEXA as a T-score of -2.5 or below.

A fragility fracture is one from a fall from standing height or less. About 1 in 2 women and 1 in 5 men will have one; the UK sees about 105,000 hip fractures a year, and 26% of those patients die within 12 months.

Every fragility fracture is a prompt to assess bone health, yet many people who fracture never start bone protection.

Bone remodels through osteoclastic resorption and osteoblastic formation. Osteoblast-derived RANKL drives osteoclast activity, and osteoprotegerin (OPG) blocks it as a decoy receptor. Osteocytes produce sclerostin, which inhibits bone formation. Oestrogen suppresses RANKL, so bone loss accelerates after the menopause.

Secondary causes matter, particularly in men and younger patients:

• •Glucocorticoids, the most common drug cause, with rapid bone loss after starting
• •Hypogonadism, including early menopause, androgen deprivation, aromatase inhibitors and REDs in athletes
• •Hyperthyroidism, hyperparathyroidism, coeliac and inflammatory bowel disease, myeloma, rheumatoid arthritis, alcohol and smoking