Osteoporosis + Osteopenia Flashcards
what is osteoporosis
decreased mass of structurally normal bone - trabecular bone loss - cortical thinning
risk factors for osteoporosis
SHATTERED pneumonic
Steroids
Hyperthyroidism
Alcohol + smoking
Thin (BMI <22)
Testosterone low
Early menopause
Renal / liver failure
Erosive / inflammatory bone disease (e.g. RA)
Dietary Ca deficient
relationship between osteoporosis and OA
osteoporosis reduces OA risk
presentation of osteoporosis
fragility fractures from low impact trauma that would not cause fracture in healthy bone e.g. NOF
vertebral fractures - vertebral collapse. Leads to back pain + height reduction – thoracic kyphosis
what scan is used to diagnose osteoporosis
DEXA scan
What is a T score
What is a Z score
on DEXA scan
T = no. of standard deviations away from youthful average
Z = no. of standard deviations away from age matched average (used in pre-menopausal women)
what T score is normal?
> -1
what T score indicates osteomalacia
-1 - -2.5
what T score indicates osteoporosis
< -2.5
what is FRAX score
gives 10 year fracture risk in patients aged 40-90
1st line fracture prevention in osteoporosis
bisphosphonates (alendronate)
+ calcium + vit D supplements
mechanism of action bisphosphonates
increase osteoclast apoptosis – reducing bone breakdown
side effects of bisphosphonates
GI inflammation - pain, dyspepsia
osteonecrosis of jaw
photosensitivity
how must bisphosphonates be taken to reduce GI side effects
take on empty stomach with lots of water
stay upright for 30 mins after taking
2nd line therapy for fracture prevention in osteoporosis
strontium ranelate - bisphosphonate alternative
Denosumab - anti-RANKL, decreases osteoclast activation
Teriparetide - PTH analogue, new bone formation
what is osteomalacia
decreased bone mineral content
biochemistry in osteomalacia
low calcium
low PO4
high ALP
high PTH
symptoms of osteomalacia
bone pain + tenderness
fractures
proximal myopahty due to decrease PO4
What is osteomalacia called in children?
How does it present?
Rickets
Knock kneed/ bow legged
Bone pain
what is seen on xray in rickets
cupped metaphyses
treatment of osteomalacia
calcium + vit D supplementation
what are Looser’s zones
pseudofractures seen on XRAY osteomalacia
symptoms of hypocalcaemia
SPASMODIC pneumonic
Spasms: +ve Trousseau’s sign
Perioral Parasthesia
Anxious
Seizures
Muscle tone increase
Orientation impaired (confusion)
Dry skin/dermatitis
Impetigo herpetiformis
Chovsteks- facial twitch on parotid tap
aldendronate can increase risk of what type of fracture
aytypical stress fracture of femoral shaft
how can:
phenytoin
atorvastatin
affect vitamin D
phenytoin - lower vitamin D levels
Atorvastatin - increase vitamin D levels
