bone disorders Flashcards
osteomalacia
abnormal bone mineralization in MATURE bone
most common cause of osteomalacia
vitamin D deficiency
sx of osteomalacia
bone pain and tenderness
muscle weakness
increased fracture risk
how is osteomalacia diagnosed
low BMD on DXA scan + clinical symptoms!
what is osteopenia
bone density lower than usual for their age (but not to the point of osteoporosis)
osteopenia results on DXA
T score between -1.0 and -2.4
what is osteoporosis
low bone mass &/or micro-architectural changes that lead to bone fragility and increased risk of fracture
how bone remodeling causes osteoporosis
most times its caused by bone remodeling becoming uncoupled– Bone resorption outpaces formation
factors that can cause failure to achieve peak bone mass
genetics
childhood calcium intake
vit D status
physical activity
what is the most common type of osteoporosis encountered in clinic?
postmenopausal osteoporosis
etiology behind postmenopausal osteoporosis
accelerated bone turnover uncoupled
two ways of treating osteoporosis
decrease bone resorption by inhibiting osteoclasts with antiresorptive agents
stimulate bone formation by stimulating osteoblasts with anabolic agents
what are the two goals of therapy with osteoporosis?
prevent bone loss
prevent fractures
who should be treated with osteoporosis?
ppl with rapid bone loss (ie. getting glucocorticoid tx)
ppl at high risk of fracture (osteoporosis on DXA or hx of low-trauma fracture or elevated risk based on FRAX)
what is the most common osteoporotic fracture?
vertebral fracture
which type of fracture carries 20% 1 yr mortality and high morbidity?
hip fractures
which type of fracture is more common in younger women? what is the mechanism of injury?
distal radius fracture
FOOSH injury
what is secondary osteoporosis?
osteoporosis d/t identifiable RF (not age and menopause)
what are the 3 identifiable RF associated with secondary osteoporosis?
glucocorticoids
endocrine d/o
malignancies
how do glucocorticoids cause osteoporosis?
bad for bone health– decreases intestinal Ca absorption, increases RANKL, suppresses osteoblasts, increases renal Ca and phos loss
increased fracture risk even on low doses for short period
what endocrine d/o are associated with secondary osteoporosis?
low testosterone
hyperparathyroidism!!!
what malignancies are associated with secondary osteoporosis?
multiple myeloma
other lymphoproliferative malignancies
how is osteoporosis diagnosed?
low-trauma fracture w/o alternative fracture is enough regardless of BMD testing!
if no fracture– DXA
what 3 parts of the body is DXA for?
lumbar spine
hip
forearmT
T vs Z score
both: how many SD from mean of populatoin
T score– sex-matched healthy controls including young
Z score– sex matched + age-matched
what does a T score of 0 mean?
same BMD on average
what two populations is the T score most useful for?
postmenopausal women
men over 50yo
T score of -2.5 means
osteoporosis
what populations is the Z score for?
premenopausal women
young men
why is the Z score not used in older population?
just because a 90 yo bones are average for their age group doesn’t mean its normal
what does a Z score less than -2.0 mean?
“lower than expected bone density for age”
can you make a dx of osteoporosis in younger person with DXA results alone?
NO
in the younger age group, only dx osteoporosis if there is fragility fracture
why should osteopenia never be diagnosed in young healthy population?
bc some young healthy people will have BMD >1SD below mean (T score of 1.0) but doesn’t mean their bone density is pathologically low
risk factors for osteoporosis
female
increasing age
postmenopausal status/testosterone deficiency
low weight
smoking
family hx
what is the strongest RF for future fragility fracture?
previous fragility fracture!
should implement aggressive risk reduction
two risk factors for falls/fractures
poor muscle strength
impaired balance or vision
risk factors for osteomalecia (online)
Less sun exposure/Vit D deficiency
Diet.
Dark skin.
Obesity.
Elderly.
Renal or hepatic disease.
Malabsorptive syndromes.
