Osteoporosis Flashcards
Risk factors for fragility fracture / osteoporosis?
- Previous low trauma fracture (standing height or less)
- Inflammatory disease (RA, IBD, connective tissue disease)
- Endocrine disease (hypogonadism inc. early menopause, hyperparathyroidism, hyperthyroidism, Cushing’s)
- Malabsorption (Coeliac)
- Low BMI
- Immobility (Spinal injury)
- Medication (Corticosteroids, aromatase inhibitors, GnRH analogues, Depo-provera)
- Family history (Hip fracture)
- Lifestyle (Alcohol and Vit D Deficiency)
How is a DXA score interpreted?
What scores are relevant?
T-score is key point
standard deviation
compared with gender-matched young adults average
< -1 - 0 = normal
- 2.5 - -1 = osteopenia
< - 2.5 = osteoporosis
Z-score shows how they compare to their age group
Available drug mechanisms and names? (4)
Anti-resporptive (decrease osteoclast activity):
Bisphosphonates
HRT
Denosumab
Anabolic (increase osteoblast activity and bone formation)
Teriparatide
What is the mechanism of action of bisphoshonates
Anti-resorptive - decrease osteoclast activity.
High affinity for hydroxyapatite, attaches to bone surface
Ingested by osteoclast, disables osteoclast, reduces bone resorption.
Bisphosphonate dosing instructions?
Take first thing in morning on an empty stomach (absorption is poor, about 5%)
Take with a big glass of water
Nothing else to eat or drink for 30 minutes
Don’t lie down after taking
Bisphosphonate side effects?
Can cause oesophagitis (reduce risk by dosing) IV can cause flu-like illness Atrial fibrillation Rare: Osteonecrosis of the jaw Atypical femoral fractures
What is osteoporosis?
A systemic skeletal disease characterised by low bone mass and microachitectural deterioration of bone tissue, with a consequent increase in bone fragility and susceptibility to fracture.
What are the main locations for osteoporotic fracture?
Wrist (Colles fracture)
Proximal femur fracture
Vertebral fracture
Prevalence?
1:2 women
1:5 men
over the age of 50
By how much does osteoporosis medication reduce fracture risk?
50%
What is the morbidity and mortality in the first year post hip fracture?
20% mortality
30% permanent disability
80% unable to carry out at least one ADL
What is bone strength compromised of?
Bone mineral density
Bone size
Bone quality
What is the effect of osteoporotic drugs?
Reduce bone turnover by decreasing osteoclast activity and increasing osteoblast activity.
Decreases resorption and increases formation.
How can risk be quantified? (2)
Clinical risk calculators
Bone densitometry
What are the clinical risk factor calculators?
Who are the used in?
Qrisk score
FRAX score
Women over 65, Men over 75, or those with risk factors.
What are the bone densitometry scans?
Dual x-ray absorpitometry (DXA)
Vertebral fracture assessment (VFA)
What is a vertebral fracture assessment?
Why are they useful?
Uses DXA machine and low dose x-ray to identify prevalence vertebral fractures (only 30% diagnosed at time)
Vertebral fractures indicate very high risk of future fracture.
What further investigations might you perform if there is evidence of low BMD or vertebral fractures?
Calcium, PTH, vitamin D Serum and urine electrophoresis (myeloma) TSH Coeliac antibody FBC, ESR Sex hormones
What are the management categories/ options for osteoporosis?
Identify and treat underlying cause e.g. hypogonadism
Lifestyle modification e.g. smoking, alcohol, calcium and vitamin D
Drug therapy
Why are bisposphonates first line?
Cheap
Effective - 50% fracture reduction
Many years experience
Give some examples of bisphosphonate medications (5)?
Oral:
Alendronate (daily or weekly)
Risedronate (daily or weekly)
Ibandronate (monthly)
IV:
Ibandronate (3-monthly)
Zoledronate (once yearly)
How can HRT be used for the prevention of osteoporosis?
Reduces risk by about 50%
Also prevents other menopausal symptoms
Okay if no contraindications
What are some risks of HRT?
Breast cancer
Stroke
Cardiovascular disease
Venous thrombo-embolic disease
What is Denosumab and how does it work?
Monoclonal antibody to RANK ligand
Prevents osteoclast differentiation and reduces activity
