1: Metabolic Bone Disease Flashcards
What is osteoporosis
condition where there is a decrease bone density leading to decrease bone strength
Which age group is most likely to develop osteoporosis
Elderly
In which gender is osteoporosis more common
Females (4:1)
What is the typical demographic affected by osteoporosis
Post-menopausal females
How can the aetiology of osteoporosis be divided
Primary
Secondary
What is type I primary osteoporosis
Post-menopausal osteoporosis
Explain briefly the pathophysiology of type I osteoporosis
- Oestrogen activates osteoblasts and inhibits osteoclasts
- At menopause oestrogen decreases
- Drop in oestrogen increases osteoclast activity and decreases osteoblast activity
What is type II primary osteoporosis
Osteoporosis due to underlying disorder
How can the aetiology of secondary osteoporosis be divided
- Iatrogenic
- Endocrine
- Other
What are 3 iatrogenic causes of secondary osteoporosis
- PPI’s
- Corticosteroids
- Anti-epileptics
What 3 drugs can cause osteoporosis
- PPI’s
- Corticosteroids
- Anti-epileptics
What are the 5 endocrine causes of osteoporosis
- Hyperparathyroidism
- Renal osteodystrphy
- Hyperthyroidism
- Cushing’s disease
- Hypogonadism
Aside from endocrine and iatrogenic causes, what else may cause secondary osteoporosis
- Alcohol abuse
- Immobilisation
What is a mneumonic to remember risk factors for osteoporosis
SHATTERED
what are the risk factors for osteoporosis
Steroid use Hyperparathyroidism, hyperthyroidism, hypercalciuria Alcohol abuse Thin (BMI <18.5) Testosterone low Early menopause Renal or liver failure Erosive or inflammatory disease Diet malnutrition, T1DM
How will osteoporosis present clinically
asymptomatic. First presentation is typically with a fragility fracture
Order the following in most likely region to suffer from an osteoporotic fracture
Vertebral > Femoral neck > Colle’s fracture > long bone
how may vertebral fractures present
- Acute back pain
- If multiple fractures may present with progressive shortening and thoracic kyphosis
if trabecular bone is affected , what type of fracture is more common
Vertebral
in which gender are trabecular fractures more common and why
Females. As males trabecular bone remains stable in time, whereas females loose trabecular bone with age
if cortical bone is affected, what fractures are more likely
Long bone
what investigations may be performed following an osteoporotic fracture
- X-Ray
- Fracture assessment tool (FRAX, Q Fracture)
- DEXA scan
- Bone profile
what tool is used to assess risk of fracture
FRAX (fracture risk assessment tool)
who is a FRAX score calculated for
All women >65y
All men >75y
Younger patients in presence of risk factors
what does FRAX score calculate
Individuals risk of osteoporotic fragility fracture in 10y
what age range is FRAX score suitable for
40-90
if FRAX shows an intermediate score what should be done
Bone mineral density score
If FRAX shows a good score, what should be done
No treatment
If FRAX shows a poor score, what should be done
Treat
Aside from FRAX, what is another tool used to assess risk of osteoporotic fracture
QFracture
what age can QFracture be used for
30-99
If a individual had their FRAX score calculated with bone mineral density and scores the following what should be done
a. low risk
b. intermediate risk
c. high risk
a. do not treat
b. consider treatment
c. treat
when should the FRAX score be re-assessed
- After 2 years if individual was in ‘consider treatment’ but did not opt to
- Change in person’s risk factors
What is used to assess bone mineral density
DEXA scan
what are 6 indications for DEXA scan
- Women >65y with one or more risk factors of osteoporosis
- Women <65y with two or more RF for osteoporosis
- Low trauma fracture
- Fragility fracture
- Starting long-term prednisolone
- Bone remodelling disorder
What dose of prednisolone should individuals be DEXA scanned before giving
> 5mg/d for 3m
What group of patients do not need a DEXA scan before treating
> 75y with two or more of the following: rheumatoid arthritis, alcohol abuse, FHx
What does a DEXA scan provide
T score
What is the T score
Provides number standard deviations individual is away from average bone mineral density of a 30y male
what does T>0 indicate
Better than reference
What does T: 0 to -1 indicate
In top 84% (normal healthy bone)
What does T: -1 to -2.5 indicate
Osteopenia
What does T: less than -2.5 indicate
Osteoporosis
What is a Z score
Bone mineral density compared to individual the same age
Why may a bone profile be requested in osteoporosis
To identify hyperparathyroidism, or other diseases.
What is first-line management for osteoporosis
lifestyle management
What 6 pieces of lifestyle advice would you provide someone with osteoporosis
- Smoking cessation
- Limit alcohol to <2 units
- Tai chi
- Weight bearing exercises
- Falls prevention program
- Calcium and vitamin D supplementation
Why is tai chi offered
To improve balance and help reduce falls
when are calcium and vitamin D supplementation offered
If evidence of deficiency
what is second-line management for osteoporosis
Aledronate (bisphosphonate)
what dose of alendronate is offered
10mg/d