Osteoporotic fractures seen in forearm (colles), spine, hip
Etiology + Pathogenesis
- Defect in obtaining peak bone mas or accelerated bone loss.
- Peak bone mass is normally achieved b/w 20-40y before gradually declining.
- Estrogen deficiency (menopause) accelerates bone loss
- Age related – fat accumulation in BM causes decrease in stell cell differentiation into osteoblasts
- Genetics – RANK and WNT pathways regulate bone turnover
- Enviro – exercise, lack of calcium diet, smoking, alcohol
- Males – hypogonandism, corticosteroids (CS), alcohol
- Corticosteroids – inhibit osteoblasts and decrease Ca intestinal absorption (leading to 2oHPTH)
- Pregnancy associated w/ back pain/vertebral fractures
- Endocrine – HPTH, cushings, hyperthyroidism
- Drugs – CS, GnTH antagonists, sedatives, alcohol, heparin
- Inflam disease – IBD, ankylosing spondylitis, RA
- GIT – malabsorption, chronic liver disease
- Others – MM, homocysteinuria, anorexia, BMI (<18)
Clinical features
- Pain, tenderness, deformity, height loss, kyphosis
Diagnosis
- DEXA – lumbar spine and hip
- History – menopause, alcohol, smoking, CS, neoplasia
- Renal function, LFT,
Treatment
- Non pharmacological
- Stop alcohol/smoking, Ca diet, hip protection
- Pharmacological
- Bisphosphonates – alendronic acid [10mg]/ risedronate [5mg oral], pamidronate (IV)
- Inhibit bone reabsorption (bind to hydroxyapatite) and osteoclast function
- Denosumab – monoclonal-antibody inhibit RANK-L
- Ca/Vit D (500/800) – used as adjuvants
- Strontium ranelate – inhibit bone reabsorption
- PTH – stimulate bone formation
- Effective in CS induced osteoporosis
- HRT – SERM , raloxifene (increased risk of embolism)
- Bisphosphonates – alendronic acid [10mg]/ risedronate [5mg oral], pamidronate (IV)