Osteoporosis Flashcards
Osteoporosis
This is a metabolic bone disease characterised by low bone mass and micro-architectural deterioration of bone tissue, leading to enhanced bone fragility and a consequent increase in fracture risk
Mechanisms behind osteoporosis
A failure to achieve adequate peak bone mass
An increase in bone resorption
Reduction in bone formation
Most significant cause osteoporosis
Post-menopausal bone loss
Clinical features of osteoporosis
Fragility fractures
Causes of osteoporosis
Post-menopausal oestrogen deficiency Corticosteroid excess Hyperparathyroidism Malabsorption Osteomalacia Hyperthyroidism Anorexia Nervosa Hypopituitarism Multiple myeloma Osteogenesis Imperfecta
Pathology of Osteoporosis
Imbalance of osteoclast and osteoblast activity.. The resorption phase occurs faster than the formation phase
Diagnosis of Osteoporosis
Bone mineral densisty is measured at the lumbar spine (L1-4) and the proximal femur using dual-energy-X-ray-absorptiometry (DEXA) scanning. A T score of less than -2.5 indicates osteoporosis and a score between 1 and 2.5 indicates osteopenia
Investigations conducted in Osteoporosis
Bone profile (calcium, phospate, alkaline phosphatase, parathyroid hormone)
25-hydroxyvitamin D and PTH
Renal function
Thyroid and liver function
Multiple myeloma screen
Treatment of oestrogen related osteoporosis
Hormone replacement therapy
Selective Oestrogen Receptor Modulator
Side effects of hormone replacement therapy
- Increased risk of blood clots
- Increased risk of breast cancer
- Increased risk of heart disease and stroke if used after large gap from menopause
Treatment of Osteoporosis
Bisphosphonates - alendronate
Use of bisphosphonates requires
- Adequate renal function
- Adequate calcium and vitamin D status
- Good dental health and hygiene advise
Side effects of bisphosphonates
- Oesophagitis
* Iritis/uveitis
Teriparatide
Version of human parathyroid hormone
SE: • Injection site irritatin
• Hypercalcaemia
• Allergy
Denosumab
monoclonal antibody against RANKL which reduces osteoclastic bone resorption. It is a subcutaneous injection given every 6 months. It is safer in patients with significant renal impairment then bisphosphonates
