Osteoporosis Flashcards
What are risk factors for osteoporosis?
Older age
Female
Reduced mobility and activity
Low BMI (<18.5 kg/m2)
Rheumatoid arthritis
Alcohol and smoking
Long term corticosteroids. >7.5mg of prednisolone/day for more than 3 months or equivalent
Other medications such as SSRIs, PPIs, anti-epileptics and anti-oestrogens
What tool can be used to assess for risk of fragility fractures and osteoporosis?
FRAX tool - predicts risk of fragility fracture in next 10y
How is bone mineral density (BMD) assessed?
DEXA scan
(Reading taken at the hip)
Can be represented as a Z score or T score
- Z score - number of standard deviations the patients bone density falls below the mean for their age
- T score - number of standard deviations below the mean for a healthy young adult their bone density is.
T score is the most important clinically and aids diagnosis
What T score mean what?
More than -1 is normal
- 1 to -2.5 indicates osteopenia
Less than -2.5 indicates osteoporosis
Less than -2.5 plus a fracture indicates severe Osteoporosis
Assessing for osteoporosis
First perform a FRAX assessment
If FRAX score doesn’t include BMD score
- Low risk - reassure
- Intermediate risk - offer DEXA scan and recalculate the risk with the results
- High risk - offer treatment
FRAX assessment using a BMD measurement - will suggest either:
- Treat
- Lifestyle advice and reassure
What is the FRAX tool?
The FRAX tool gives a prediction of the risk of a fragility fracture over the next 10 years.
Inputs information such as age, BMI, co-morbidities, smoking, alcohol and family history
Can also enter BMD result from a DEXA scan for a more accurate result if that is available to you
Management of osteoporosis - conservative
Activity and exercise
Maintain healthy weight
Adequate calcium intake
Adequate vitamin D
Avoid falls
Stop smoking and reduce alcohol
Management of osteoporosis - medical
Bisphosphonates are first line e.g. alendronate OW 70mg
Calcium and vitamin D supplementation - (in patients at risk of fragility fractures with an inadequate intake of calcium or inadequate sun exposure)
Other medical options, if bisphosphonates CI, not tolerated or ineffective:
- Denosumab
- Strontium ranelate
How do bisphosphonates work?
By interfering with osteoclasts and reducing their activity, preventing the reabsorption of bone.
What are some important side effects to remember for bisphosphonates?
Reflux and oesophageal erosions.
Atypical fractures (e.g. atypical femoral fractures)
Osteonecrosis of the jaw
Osteonecrosis of the external auditory canal
What is denosumab how does it work?
Denosumab is a monoclonal antibody that works by blocking the activity of osteoclasts.
What is strontium ranelate and how does it work? Potential side effect?
Strontium ranelate is a similar element to calcium that stimulates osteoblasts and blocks osteoclasts
But it increases the risk of DVT, PE and myocardial infarction.
Follow up for osteoporosis patients?
Repeat FRAX and DEXA scans after 3-5y
(treatment holiday should be considered if their BMD has improved and they have not suffered any fragility fractures - a break from treatment before repeating the assessment)
