Osteoporosis Flashcards
What is important in the prevention of fatigue damage and the maintenance of calcium homeostasis
bone remodelling and resorption
What are the three phases of bone remodelling
Resorption
Reversal
Formation
What happens during resorption
osteoclasts remove matrix and mineral on the trabecular surface or within the cortical bone
What happens during reversal
mononuclear cells, possibly of monocyte/ macrophage lineage, appear on the bone surface and may provide signals for osteoblast differentiation and migration.
A layer of glycoprotein-rich material is laid down on the resorbed surface to which the new osteoblasts can adhere
What happens during formation
Osteoblasts lay down bone to replace resorbed bone
What is the factor that osteoblasts express and what does it do
RANKL
it interacts with a receptor on osteoclast precursors called RANK resulting tin the activation and differentiation of osteoclasts
What is osteoporosis
Skeletal disease characterised by reduced bone mass and micro architectural deterioration, resulting in increased bone fragility and fracture risk
How many women are affected and how many men are affected worldwide
1 in 3 women
1 in 8 men
What i osteoporosis characterised by
increased bone turnover
When is the maximum bone mineral density (peak bone mass)
achieved by the age of 30-40
Where do osteoporosis-related fractures associated with minor trauma tend to occur
at sites comprising more than 50% trabecular bone
Where are the sites comprising more than 50% trabecular bone
vertebral bodies - backache that subsides after 3 months
Proximal femur - mortality is increased by 20% in the first year
Distal radius - Colles’ fracture
How is bone mineral density measured
using dual-energy X Ray absorptiometry (DEXA)
What does the T score mean
it compares the patient\s BMD with that of a young reference population
A T score of -2.5 or less is osteoporosis in healthy postmenopausal women and men aged 50+
What T score is used for a diagnosis of osteoporosis
the lowest of the lumbar spine, proximal femur or distal radius
What is osteopenia
When a patent has a T score of -2.5 - -1.0
What does the Z score do
it compared the patients BMD to that of an age-matched reference population
Z scores should be used for premenopausal women and men under 50
What are the main aims of treatment
alleviation of symptoms (analgesics)
Reduction of the risk of further fractures
Treatment of the underlying cause (leads to a partial recovery of bone mass)
What should all patients with a low BMD receive
adequate calcium and vitamin D supplementation
Advice regarding lifestyle modifications
What are some lifestyle modifications that are useful for patients with a low BMD
weight bearing exercise
smoking cessation
avoidance of excess alcohol
fall prevention counselling
What can be used to calculate the 10 year probability of hip fracture and major osteoporotic fracture
FRAX calculator
What is an alternative therapy for those that can’t tolerate bisphosphonates
strontium ranelate or raloxifene
Name 2 bisphosphonates often used as first line therapy
Alendronate or risedronate
How should bisphospohonated be taken
once weekly
with a full glass of water half an hour before breakfast to help absorption
do not lie down for 30 minutes after taking
What do bisphosphonates do
prevent fracture of the hip, spine and forearm
What is the treatment for men with osteoporosis and hypogonadism
testosterone replacement therapy
What is the aim of preventing osteoporosis
maximise peak bone mass and reduce the rate of bone loss
What are some preventative measures of osteoporosis
Adequate calcium and vitamin D intake
regular weight bearing exercise
avoidance of smoking and alcohol
What might be useful in predicting the rate of future bone loss
markers of bone turnover
How often should a patient with osteoporosis be followed up
most guidelines recommend a follow-up DEXA scan 1 year after stating treatment
Then a DEXA scan after 2 -3 years
What might a decrease of less than 40 % be due to
Non-compliance or poor absorption
If a patient is receiving PTH treatment, what should be measured during the course of treatment
Srum calcium
renal function
uric acid prior to initiation of therapy
What drug should be considered in patients with a T score less than -2.5 and at least one fragility fracture who do not tolerate bisphosphonates
Teriparatide
