deck_5448368

Question 1

Which has a higher turnover rate, trabecular or corticol bone?

Answer 1

trabecular

Question 2

What are the biochemical markers of bone formation?

Answer 2

-Alk P-Osteocalcin-Carboxyterminal propeptide of type I collagen (P1NP)

Question 3

What are the biochemical markers of bone resorption?

Answer 3

N-telopeptideCarboxyterminal of type I collagen (CTX-1)

Question 4

What is osteoporosis?

Answer 4

a skeletal disorder characterized by compromised bone strength predisposing to fracture. Bone strength reflects the integration of bone density and bone quality

Question 5

How is osteoporosis measured/tested?

Answer 5

Central DEXA currently the gold standard to measure bone mineral density

Question 6

What is the risk of a fracture with a DEXA of -1, -2, and -3

Answer 6

These numbers represent standard deviations from normal bone density and the risk doubles per each SD away from the meanso if O SD= 1 risk-1= 2x more likely-2= 4x-3=8x

Question 7

What DEXA T score is diagnostic of osteoporosis?

Answer 7

-2.5 (from -1 to -2.5= osteopenia) ORLow-trauma (aka fragility) fracture with a T-score greater (more positive) than -2.5

Question 8

How much does a single vertebral fracture increase the risk of another? 2 vertebral fractures?

Answer 8

1 vertebral fracture increases risk by 5x (and increases risk of hip fracture by 2x), and 2 increases by 12x

Question 9

Even at the same T-score, _____ increases the risk of fracture

Answer 9

age

Question 10

What drugs increase the risk of fracture?

Answer 10

glucocorticoids, TCAs, SSRIs, PPIs, long-acting benzodiazepines, antipsychoticsanticonvulsants, aromatase inhibitors, androgen deprivation therapy (prostate cancer Tx)

Question 11

Risk factors for fracture?

Answer 11

Age, previous low trauma Fx, low BMI, current cigarette smokingsteroid use, rheumatoid arthritis, high alcohol intake, fam Hx of fracture

Question 12

Who should be treated with osteoporotic Tx?

Answer 12

-those with T-score less than 2.5 after age 50-osteopenia with Hx of a fragility fracture-Use FRAX score to decide to treat those younger than 50 with a T- or Z-score less than 2.5 or older than 50 with a t-score greater than -2.5

Question 13

How do you interpret FRAX

Answer 13

A 10-yr risk of 3+% for hip fracture or 20+% for major osteoporotic fracture is sufficient to initiate pharamcological treatment

Question 14

What things in a osteoporotic patient might suggest Cushing’s syndrome being the underlying cause?

Answer 14

chronic steroid use, obesity, accelerated weight gain, buffalo hump

Question 15

What things in a osteoporotic patient might suggest primary hyperparathyroidism being the underlying cause?

Answer 15

hypercalcemia and an elevated PTH with decreased Phosphate

Question 16

What things in a osteoporotic patient might suggest acromegalybeing the underlying cause?

Answer 16

arthralgias, large hands and feet, obstructive sleep apnea

Question 17

What things in a osteoporotic patient might suggest secondary hyperparathyroidism being the underlying cause?

Answer 17

kidney stones

Question 18

What things in a osteoporotic patient might suggest hypogonadism (low testosterone)being the underlying cause?

Answer 18

low libido, erectile dysfunction, loss of muscle mass

Question 19

What things in a osteoporotic patient might suggest hyperthyroidism being the underlying cause?

Answer 19

suppressed TSH, tachycardia, diarrhea, etc.

Question 20

How is idiopathic osteoporosis treated?

Answer 20

1) optimize lifestyle (stop alcohol and tobacco, increase physical activity, maintain calcium and vitD(30+ng/mL))2) Pharm intervention (bisphosphonates, etc.)

Question 21

What is osteomalacia/rickets?

Answer 21

failure to mineralize bone leading to softening of bone most commonly due to vitD deficiency (nutritional, no sunlight, liver disease)

Question 22

What is Type I VitD Dependent Rickets?

Answer 22

AR disease caused by a defect in 1a-hydroxylase

Question 23

What is Type II VitD Dependent Rickets?

Answer 23

AR disease caused by defect in receptor response to activated vitD

Question 24

What is Paget disease of bone?

Answer 24

localized area of lytic then sclerotic bone formation that leads to formaiton of large amounts of poor quality bone that can manifest as enlarged skull, bony pains, and extremity deformitiesComplications: hearing loss, bone tumors (osteosarcoma), fractures

Question 25

Tx of Paget's disease?

Answer 25

single IV dose (because they have a very long half-life) of bisphosphonates is typically curative

Question 26

Labs for Paget's disease?

Answer 26

isolated ALP

Question 27

What is osteopetrosis?

Answer 27

Too much brittle bone is made (labs are normal and DEXA will be VERY positive) but breaks like chalk

Question 28

What is osteitis fibrosa cystica?

Answer 28

disease caused by hyperparathyroidism that is primarily seen in primary hyperpTH and ESRD patients with very high PTH levels. 

Question 29

How does OFC present in labs?

Answer 29

elevated PTH, elevated calcium in primary HPT and normal/low-normal calcium in ESRD patients. Elevated ALP

Question 30

What is the most sensitive and specific radiologic finding of OFC?

Answer 30

subperiosteal resorption of cortical bone, best seen in high-resolution films of the phalanges. A similar process in the skull leads to a salt-and-pepper appearanceBone cysts or brown tumors may present as osteolytic lesions

Question 31

How does OFC present histologically?

Answer 31

increase in osteoclasts, marrow fibrosis, and cystic lesions that may contain fibrous tissue (brown tumors)do a DEXA on the forearm, mostly cortical bone

Question 32

How does OFC present clinically?

Answer 32

bone pain and sometime spathologic fractures. This osteoporosis is due to preferential loss of CORTICAL bone (osteoporosis is a loss of trabecular bone)

Question 33

What is fibrous dysplasia?

Answer 33

Replacement of bone with fibrous connective tissue and poorly formed trabecular bone due to activating mutations in GNAS 1. 

Question 34

What are the types of fibrous dysplasia?

Answer 34

It can be monostotic (single bone) or polyostotic (multiple bones)Association of the polyostotic form with café au lait spots and hyperfunction of an endocrine system such as pseudoprecocious puberty of ovarian origin is known as McCune-Albright syndrome (MAS).

Question 35

What is the most common form of fibrous dysplasia?

Answer 35

The monostotic form is the most common and is usually diagnosed in patients between 20 and 30 years of age without associated skin lesions.

Question 36

Describe the polyostotic form of fibrous dysplasia

Answer 36

typically manifests in children under 10 years old and may progress with age.In polyostotic fibrous dysplasia, the lesions most commonly involve the maxilla and other craniofacial bones, ribs, and metaphyseal or diaphyseal portions of the proximal femur or tibia.

Question 37

What are the symptoms of fibrous dysplasia?

Answer 37

Expanding bone lesions may cause pain, deformity, fractures, and nerve entrapment.

Question 38

Labs for fibrous dysplasia?

Answer 38

Hypophosphatemia (may be due to production of FGF-23 by the abnormal fibrous tissue). Ca, PTH, vitamin D – are all normal. Markers of bone turnover can be elevated (ALP)

Question 39

Radiographic findings of fibrous dysplasia

Answer 39

In long bones, the fibrous dysplastic lesions are typically well-defined, radiolucent areas with thin cortices and a ground-glass appearance. Lesions may be lobulated with trabeculated areas of radiolucency

Question 40

How is fibrous dysplasia treated?

Answer 40

-Asymptomatic patients may be observed every six months with serial radiographs.-Symptomatic patients (pain and deformity) may benefit from curettage, bone grafting, and stabilization.-Bisphosphonate therapy may improve symptoms . 

Question 41

What is the prognosis of fibrous dysplasia?

Answer 41

– The deformity may progress with skeletal growth-Usually static after growth ceases at puberty (may be reactivated with pregnancy)