R/O - Metabolic bone disease Flashcards Preview

Year 2 Specialty Medicine > R/O - Metabolic bone disease > Flashcards

Flashcards in R/O - Metabolic bone disease Deck (37)
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1
Q

definition: osteoporosis

A

bone deterioration with:

  • reduced bone mass
  • disruption of micro architecture of bone
2
Q

what is the T score cut off for osteoporosis?

A

-2.5 (-2.5 or less means osteoporosis diagnosis)

3
Q

what type of fracture has the highest mortality?

A

hip fracture

4
Q

what is the most common reason for nursing home admittance?

A

hip fractures

5
Q

what is the gold standard screening for diagnosing and monitoring osteoporosis?

A

DXA

6
Q

what is a Z score?

A

age matched control

7
Q

low bone density (osteopenia) is a T score in what range?

A
  • 1.0 down to -2.5
8
Q

what is a normal T score?

A

-1.0 to 1.0

9
Q

anyone with a fragility fracture by definition has:

A

osteoporosis

10
Q

when should a T score be used?

A
  • comparing BMD to a person of same age
  • younger than peak bone mass
  • pre-menopausal women
  • men under 50 yo
  • evaluating for secondary causes of osteoporosis
11
Q

recommend BMD testing in women over ____ and men over ____

A
  • women: 65

- men: 75

12
Q

in postmenopausal women and men 50-70, recommend BMD testing when there is concern based on ______________________

A

risk factor profile

13
Q

the WHO FRAX algorithm was developed to calculate:

A
  • 10 yr probability of a hip fracture

- 10 yr probability of any major osteoporotic fracture (defined as hip, forearm, humerus)

14
Q

consider initiating treatment in postmenopausal women and men over 50 with T score of ______ AND _________

A
  • 1 to -2.5

- 10 yr hip fracture probability 3% or more

15
Q

how often is BMD testing recommended?

A

every 2 years

16
Q

what are limitations of FRAX?

A
  • patients naive to treatment

- only uses T score from hip and does not accomodate peripheral sites or spine T score

17
Q

what are the anticatabolic drug therapies for osteoporosis?

A
  • bisphosphonates
  • SERM
  • denosumab
18
Q

what is the anabolic drug therapy for osteoporosis?

A

teriparitide

19
Q

what is the MOA of bisphosphonates?

A
  • bind to bone mineral
  • concentrate at sites of bone resorption
  • release and intracellular uptake during resorption
  • loss of resorptive function
20
Q

bisphosphonate action depend on what two factors?

A
  • mineral binding

- effects of osteoclasts

21
Q

what is the MOA of denosumab?

A
  • binds RANK-L and inhibits osteoclast-mediated bone destruction
  • osteoclast formation, function, and survival inhibited
  • bone resorption inhibited
22
Q

what factors determine PTH effects on bone?

A
  • administration

- dose

23
Q

high dose (continuous) PTH has what effect on bone?

A

catabolic

24
Q

low dose (daily) PTH has what effect on bone?

A

anabolic

25
Q

paget disease of bone is characterized by abnormalities of the ______________ (cell type) and there is _______________ (accelerated / decreased) bone turnover and abnormal bone remodeling

A
  • osteoclast

- accelerated

26
Q

what is the inheritance of PDB?

A

AD

27
Q

what are the labs in PDB?

A
  • increased alk phos (bone specific AP)
  • bone turnover markers increased
  • calcium and phosphate typically NORMAL
28
Q

what test should be done in patients with PDB?

A

baseline bone scan

29
Q

what do you monitor in PDB?

A

alk phos

30
Q

what is the medication of choice for PDB?

A
  • bisphosphonates (zoledronic acid)
31
Q

definition: rickets

A

deficient mineralization at the growth plate, as well as architectural disruption of this structure

32
Q

definition: osteomalacia

A

impaired mineralization of the bone matrix

33
Q

rickets and osteomalacia occur together as long as:

A

growth plates are open (only osteomalacia occurs once the growth plates close)

34
Q

calcipenic rickets is usually caused by:

A

dietary deficiency of vitamin D and/or calcium (most common form)

35
Q

phosphopenic rickets in children and adolescents is almost always caused by:

A
  • renal phosphate wasting (usually isolated)
  • generalized tubular disorder (e.g. Fanconi)
  • inadequate dietary phosphate / intestinal malabsorption (rare)
36
Q
  • delayed closure of fontanelles
  • parietal and frontal bossing
  • enlargment of costochondral junction
  • widening of wrist
  • lateral bowing of femur and tibia
A

rickets

37
Q
  • elevated alk phos
  • reduced serum calcium and phosphorus
  • low urinary calcium
  • low 25-OH vitamin D
  • elevated PTH
A

osteomalacia