More bone disease

Question 1

Paget disease of bone

Answer 1

imbalance btw osteoclast and osteoblast function, usually seen in late adulthood. osteoclasts begin resorbing bone wildly. eventually, the osteoblasts activate and try to lay down as much bone as possible. then, osteoclasts burnout, and then you just have osteoblasts laying down as much bone as possible in a rush. stages: lytic, mixed, sclerotic (quiescent)
May be a viral process. involves a few bones, not the whole skeleton.
end result: thick, sclerotic bone that fractures easily

Question 2

What cell is regulated by PTH

Answer 2

osteoblast. then the osteoblast directs osteoclast resorption

Question 3

histo finding of paget disese

Answer 3

mosaic pattern of lamellar bone

Question 4

clinical features and lab features of paget disease

Answer 4

bone pain from microfractures, incr. hat size, hearing loss (narrowing the foramen), lion like faces, isolated, elevated alk phos

Question 5

Tx of paget disease

Answer 5

calcitonin and bisphosphonate

Question 6

complications of paget disease

Answer 6

high output cardiac failure (AV shunts through thick bone). osteosarcoma.

Question 7

Osteomyelitits

Answer 7

infectionsof marrow space and bone. usually in kis. usually bacterial from hematogenous spread. seeds metaphysis in kids (from transient bacteremia). epiphysis in adults (from open wounds). remember, epiphysis at top

Question 8

causes of osteomyelitis

Answer 8

S. aureus, N gonorrhea, salmonella (sickle cell diseae), pseudomonas (diabetic, IV drug user), pasturella (dog/cat bite), TB

Question 9

Clinical features of osteomyeltis

Answer 9

bone pain w/ fever and leukocytosis. lytic focus surround by sclerosis on x ray. Dx by blood culture

Question 10

aseptic necrosis: associated diseases, complications

Answer 10

ischemic necrosis of bone and bone marrow from trauma/fracture, steroids, sickle cell (esp. in finger or toe bones), caisson disease (gas emboli preciptate out of the blood).
complications: osteoarthritis, fracture

Question 11

Most common site of aseptic necrosis:

Answer 11

femoral head from insufficiency of medial circumflex femoral artery

Question 12

osteomalacia lab findings

Answer 12

decr. serum Ca and phosphate, increased alk phos and PTH

Question 13

What are findings associated with hypervitaminosis D

Answer 13

incr. Serum Ca and PO4 3-, normal Alk phos, decr. PTH. caused by over-supplementation or granulomatous disease (like sarcoid)