8: Disorders of bone health including osteoporosis Flashcards
What is osteoporosis?
Low bone mass leading to increase in bone fragility, risk of pathological fracture
A ___ effect often occurs with several fractures occuring in sequence in people with osteoporosis.
domino
Who tends to get osteoporosis?
Elderly women
Where do pathological fractures commonly occur in osteoporosis?
Neck of femur
Vertebral body
Distal radius
Humeral neck
What percentage of hip fracture patients die within a year?
20%
Your risk of fracture (increases / decreases) as you get older.
increases
Patients with spinal fractures develop a thoracic (kyphosis / lordosis).
thoracic kyphosis
At which sites does bone remodelling occur?
Bone remodelling sites
I appreciate this isn’t very helpful
What minerals are stored in bone?
Calcium
Phosphate
Which cells
a) resorb
b) form bone?
a) Osteoclasts
b) Osteoblasts
The new bone formation by osteoblasts is then mineralised with what?
Calcium
Phosphate
Osteoporotic bone has a reduced (mass / density).
both
Osteoporosis has a large ___ component.
genetic
People who are very (underweight / overweight) can develop osteoporosis.
underweight
Which hormones affect bone mass?
PTH and Calcitonin
Sex hormones
At what age is peak bone mass usually obtained?
Around 25
When do women experience a sudden drop in bone mass?
Menopause
Once bone mass has dropped below the __ threshold, pathological fracture is more likely.
fracture threshold
What are some non-modifiable risk factors for fragility fracture?
Age
Gender
Ethnicity
PMX fracture
FX
Menopause
Other diseases e.g Coeliac
What are some modifiable risk factors for fragility fracture?
BMD
Alcohol
Weight
Smoking
Physical activity
What calculators can be used to determine risk of fragility fracture?
QFracture
WHO calculator
People with a QFracture score of more than 10% should be referred for what?
DEXA scan
Who is assessed for osteoporosis?
Anyone >50 with risk factors
Anyone <50 with lots of risk factors
What does a DEXA scan determine?
BMD
Bone mineral density
What are the BMD thresholds for
a) normal bone mass
b) osteopenia
c) osteoporosis
d) severe osteoporosis?
Normal - BMD within 1 standard deviation of mean
Osteopenia - BMD > 1 SD below adult mean
Osteoporosis - BMD > 2.5 SDs below adult mean
Severe osteoporosis - “ with fragility fracture
What are some secondary causes of osteoporosis?
Hyperthyroidism
Hyperparathyroidism
Cushing’s
Coeliac
IBD
What is the daily recommended intake of calcium?
700mg in normal people
1.0g per day in those with osteoporosis
What drugs are used to treat osteoporosis?
Calcium & Vitamin D supplementation
Oral biphosphonates or IV zoledronic acid - inhibits osteoclasts
Denosumab - inhibits osteoclasts
Teriparatide - recombinant PTH, promotes bone growth
Deficiency of which
a) vitamin
b) mineral
can cause osteoporosis?
Vitamin D
Calcium
How do biphosphonates work?
Reduce osteoclast number and activity
Bone resorption slowed down
What is an example of an
a) oral
b) IV bisphosphonate?
a) Oral - aldendronate
b) IV - zoledronic acid
How should biphosphonates be taken?
30 mins before breakfast with a glass of water
What is an IV biphosphonate used in those who can’t tolerate biphosphonates?
Zoledronic acid
How often is zoledronic acid administered?
Once a year
What agents can be used to block the receptors controlling osteoclast activity?
Biologic agents
e.g denosumab
What is teriparatide?
How does it work?
Analogue parathyroid hormone
Stimulates bone growth rather than stopping bone loss
In terms of DEXA scans, what is a
a) T score
b) Z score?
T score - BMD compared to that of a young, healthy adult
Z score - BMD compared to normal for age, sex and ethnicity
Below which T score following a DEXA scan should osteoporosis be treated with drugs?
< 2.5
If a patient with osteoporosis is using steroid, below which T score should they be started on drugs?
< 1.5
Which type of drug accelerates osteoporosis by affecting calcium metabolism?
Steroids
In patients using steroids long-term, what should you consider giving them?
Calcium supplements
What is Paget’s disease?
Abnormal bone turnover
Waves of osteoclast > osteoblast activity
Which liver enzyme is commonly raised in Paget’s disease?
ALP
How is Paget’s disease treated?
Analgesics
if no relief
Biphosphonates
What is osteogenesis imperfecta?
Genetic disorder causing fragility fractures
What are some odd signs of osteogenesis imperfecta?
Blue sclerae
Malformed dental arches
What causes blue sclerae and dentinogenesis imperfecta in patients with OI?
Collagen abnormalities
How does osteogenesis imperfecta present?
Fragility fractures in childhood
