Ortho path

Question 1

osteoid vs woven bone

Answer 1

both are immature, rapidly formed. woven is mineralized

Question 2

Types of lamellar bone

Answer 2

cortical (compact) and cancellous (spongy, trabecular)

Question 3

balance b/w blasts and clasts

Answer 3

clasts break down bone and release factors which lead to differentiation into blasts

Question 4

Osteogenesis Imperfecta: defect, calluses

Answer 4

Deficiency in Type1 collaen. fractures heal with excess callus

Question 5

Osteoporosis

Answer 5

Postmenopausal (high turnover): estrogen deficiency means less OPG. Senile (low-turnover): osteoblasts just poop out

Question 6

Rickets/Osteomalacia: defect, x-ray findings,

Answer 6

Vit.D deficiency. You get uncalcified osteoid in zone of hypertrophy. Metaphysial flare. Renal failure leads to decreased Ca and ^phosphate

Question 7

Hyperparathyroidism: ditty, which bone type is affected most? characteristic findings?

Answer 7

Moans, bones, stones, psychiatric overtones. Cortical>trabecular. hemosiderin deposits (brown tumor)

Question 8

paget disease: defect, staging, characteristic findings, associations?

Answer 8

blast/clast dyssynchrony. Three phases: lytic, mixed, sclerotic. reversal cement lines. Paramyxovirus infection, cardiac failure

Question 9

Osteopetrosis: defect, effect, complications

Answer 9

clasts can’t acidify pits. medullary canal fills with bone. Anemia, thrombocytopenia, fractures

Question 10

Acute osteomyelitis: cause, result, characteristic features

Answer 10

Staph aureus infection. Uses Volkman canals to spread. Ischemic necrosis of bone. Dead bone (sequestrum) surrounded by PMNs. New bone (involucrum) forms around dead.

Question 11

Osteochondroma (exostosis): cause, characteristics

Answer 11

EXT1 mutation. Ice cream cone growing away from physis. marrow space contiguous w/ bone’s. If cartilage cap > 3cm, malignant

Question 12

Enchondroma: xray, invasive? multiple?

Answer 12

benign. arc&ring lobules. non invasive. enchondromatosis

Question 13

Giant cell tumor: cell type, treatment

Answer 13

osteoclastic cells. Lytic lesion. en bloc excision

Question 14

Osteoid osteoma: presentation, microscopic,

Answer 14

nocturnal pain relieved by NSAIDs. Nidus of woven bone spicules lined by osteoblasts

Question 15

fibrous dysplasia: microscopic, two types

Answer 15

fibro-osseous lesion lacking osteoblastic rimming. Monostotic FD, Polystotic

Question 16

McCune-Albright

Answer 16

polystotic FD + cafe au lait spots

Question 17

osteosarcoma: unique? location? tx? prognosis?

Answer 17

neoplastic cells directly produce bone. Metaphysis in younger pts, craniofacial in older. Prosthetic while in tx. Prognosis good if >90% responsive

Question 18

chondrosarcoma: age

Answer 18

older ppl. Lobulate arc&ring.

Question 19

Ewing sarcoma: unique, cause, who, where, microscopic

Answer 19

neuroectodermal tumor. t(11;22). young males. diaphysis. Small blue round cells. Onionskin and sunburst of periosteum

Question 20

osteoarthritis: what joints, cause

Answer 20

large, esp knee. lumbar. PIP/DIP. mechanical stres»apop of chondrocytes.

Question 21

OA: changes

Answer 21

fibrillation of cartilage, fragmentation, loss. Osteophytes crack and give rise to subchondral cysts

Question 22

RA: what ab’s

Answer 22

RF: IgM directed against IgG