Osteoporosis

Definition

  • Low bone mass and microarchitectural deterioration causing fragility and fracture risk
  • WHO definition is a DXA T-score of -2.5 or lower at hip or spine
  • Osteopenia is a T-score between -1 and -2.5
  • A minimal trauma fracture establishes the diagnosis clinically
  • About 1 in 2 women and 1 in 3 men over 60 will have a minimal trauma fracture

Aetiology

  • Primary, postmenopausal and age related
  • Secondary causes are corticosteroids, hypogonadism, hyperthyroidism, hyperparathyroidism, coeliac disease, myeloma, alcohol and smoking
  • Aromatase inhibitors and androgen deprivation therapy
  • Anticonvulsants and proton pump inhibitors

Investigations

Osteoporosis - Role of the Surgeon, comparison of healthy and osteoporotic vertebral bone
Comparison of healthy and osteoporotic vertebral bone. Image by Turner Biomechanics Laboratory, Wikimedia Commons, CC0.
  • DXA of hip and lumbar spine
  • Calcium, vitamin D, PTH, renal and thyroid function, and myeloma screen
  • Fracture risk with the Garvan calculator or FRAX
  • Thoracolumbar spine radiographs for height loss or back pain
  • Coeliac serology and testosterone in men where indicated

Management

  • Calcium and vitamin D replacement
  • Resistance and balance exercise, falls prevention
  • Antiresorptives first line, bisphosphonates or denosumab
  • Anabolic agents for very high risk or multiple vertebral fractures
  • Zoledronic acid after hip fracture reduced new fractures and mortality (HORIZON Recurrent Fracture Trial, NEJM 2007)
  • Fracture liaison services close the treatment gap after fragility fracture
  • See Inhibitors of Bone Resorption and Vitamin D

Fracture Liaison

  • Fracture liaison services identify and treat patients after a fragility fracture
  • Treatment after a first fracture prevents further fractures
  • Repeat DXA every 2 to 3 years to monitor treatment

Reviewed by Professor Phong Tran, Head of Orthopaedic Surgery, Western Health. Last updated 10 October 2026.