Metabolic Bone Diseases - Osteoporosis Flashcards
Define OP?
Low bone mass & Micro-architectural deterioration leading to enhanced fragility & fracture risk
How do we determine someone’s fracture risk (& so OP risk)?
FRAX
the WHO’s Fracture Risk Assessment Tool
It’s an online risk calculator
What is primary OP?
Loss of bone mass due to aging, mostly in post-menopausal women
What is secondary OP?
Loss of bone mass due to a drug or other disease
How does OP help us understand little old ladies?
If trabecular bone is affected they get crush fractures in their vertebrae. One of the reasons little old ladies are so little.
If cortical bone is affected they get long bone fractures, hence all the broken hips
A huge number of things can cause secondary OP. List some of the major ones?
RA Cushing's disease IBD Malabsorption by any cause e.g. CF, coeliac or CP Liver damage e.g. PBC Steroids Hyper/hypoparathyroidism Low Testosterone
SHATTERED is a useful mnemonic for OP risk factors:
S - Steroids H - Hyperthyroid/parathyoid/calciuric A - Alcohol & Tobacco T - Testosterone low e.g. anti-androgens T - Thin (<22BMI) E - Early Menopause R - Renal or liver failure E - Erosive bone disease e.g. RA D - Dietary Ca low or malabsorption
How do we test for OP?
FRAX and/or Q fracture risk calculators
DEXA bone scan
Bloods (ALKP/ Ca / PO4 all normal)
What is a DEXA bone scan?
Basically a special X-ray that determines bone density
Used on any patient >50 who gets a low-trauma fracture
How do we treat OP?
Start by minimising the risk factors
Fall prevention strategies
Ca/VitD supplements
Meds
What meds are used in OP?
Bisphosphonates Raloxifene (SERM) Denosumab (Monoclonal Ab) Teriparatide HRT
How do we give bisphosphonates for OP?
Orally
Requires good renal function & Vitd/Ca status
Notify dentist
What is Raloxifene?
A selective Oestrogen Receptor Modulator (SERM)
Reduces vertebral fracture rates but risks hot flushes and blood clots
How does Denosumab work?
Given by SC injection every 6 months it decreases osteoclast activity
Best in patients with renal impairment who can’t take bisphosphonates
What is Teriparatide?
Recombinent Parathyroid Hormone