MSK/CT

Question 1

short limbs, big head?

Answer 1

achondroplasia
FGFR3 activation –> chondrocyte proliferation inhibited
85% sporadic; AD inheritance

**failure of endochondral ossification only

Question 2

bone changes in osteoporosis?

Answer 2

trabecular (spongy) bone loses mass and interconnections

NORMAL bone mineralizations and lab values

Question 3

dense bones prone to fracture, CN impingement/palsies?

Answer 3

osteopetrosis
mutation –> defective OCs (e.g. carbonic anhydrase II) - can’t generate acid for resorption

• • pancytopenia, extramedullary hematopoiesis
• • BM txp potentially curative

Question 4

increased hat size, hearing loss, high-output heart failure?

Answer 4

Paget’s dz
long bone chalk-stick fx
mosaic pattern of woven and lamellar bone
increased AV shunting –> HF

** increased risk of osteogenic sarcoma

Question 5

stages of Paget dz?

Answer 5

lytic: OCs
mixed: OBs and OCs
sclerotic: OBs
quiescent: minimal activity

Question 6

causes of avascular necrosis?

Answer 6

alcohol
sickle
steroids
pancreatitis
trauma
Legg-Calves-Perthes
the bends

Question 7

lab values in osteoporosis?

Answer 7

NORMAL except for DEXA

Question 8

lab values in osteopetrosis?

Answer 8

normal or low Ca in very severe/malignant dz

Question 9

lab values in Paget dz?

Answer 9

elevated ALP

otherwise normal

Question 10

lab values in osteomalacia/Rickets?

Answer 10

Ca and Ph decreased

ALP and PTH increased

Question 11

lab values in hypervitaminosis D?

Answer 11

Ca and Ph increased
PTH decreased
normal ALP

Question 12

lab values in 1ary hyperparathyroidism?

Answer 12

increased Ca, decreased Ph

increased ALP and PTH

Question 13

lab values in 2ary hyperparathyroidism?

Answer 13

decreased Ca, increased Ph

increased ALP and PTH

Question 14

“brown tumors,” subperiosteal thinning?

Answer 14

osteitis fibrosa cystica

= bony changes 2/2 hyperparathyroidism

Question 15

locally aggressive benign tumor, soap bubble appearance?

Answer 15

giant cell tumor = osteoclastoma
often at knee
epiphyseal end of long bones
20-40 yo

Question 16

mature bone with cartilaginous cap?

Answer 16

osteochondroma
MC benign tumor
males < 25 yo

Question 17

Codman triangle or sunburst pattern on XR?

Answer 17

osteosarcoma
metaphysis of long bones, esp knee
bimodal ages: 10-20, >65
tx: surgical en bloc resection and chemotherapy

** predisposing factors: Paget, bone infarct, radiation, retinoblastoma, Li-Fraumeni

Question 18

anaplastic small blue cell tumor, onion skinning?

Answer 18

Ewing sarcoma
diaphysis of long bones, pelvis, scapula, ribs
boys < 15yo

** t(11;22) translocation

Question 19

complications of Sjogrens?

Answer 19

dental caries

MALT lymphoma

Question 20

why do gout attacks happen after alcohol consumption?

Answer 20

alcohol metabolites compete for same excretion sites as uric acid

Question 21

rhomboid, weakly birefringent crystals?

Answer 21

pseudogout = calcium pyrophosphate crystals
assoc with hemochromatosis, hyperparathyroidism, OA
tx: NSAIDs, steroids, colchicine (ppx)

Question 22

dactylitis, pencil-in-cup deformity?

Answer 22

psoriatic arthritis

Question 23

infections assoc with Reiter?

Answer 23

GI: Shigella, Salmonella, Yersinia, Campylobacter

Chlamydia

Question 24

common causes of death in SLE?

Answer 24

CV disease
infections
renal disease

Question 25

lab findings in anti phospholipid syndrome?

Answer 25

lupus anticoagulant
anticardiolipin
anti-beta2 glycoprotein

** LAC and anticardiolipin –> false pos VDRL and prolonged PTT

Question 26

elevated serum ACE and CD4/CD8 ratio?

Answer 26

sarcoidosis
B/L adenopathy, coarse reticular opacity, hilar/mediastinal adenopathy
widespread NONcaseating granulomas

** hypercalcemia 2/2 increased 1alphahydroxylase –> vit D activation in MACROPHAGES)

Question 27

tx of fibromyalgia?

Answer 27

regular exercise
TCAs/SNRIs
anticonvulsants

Question 28

endomysial inflammation with CD8 cells?

Answer 28

polymyositis

Question 29

perimysial inflammation with CD4 cells?

Answer 29

dermatomyositis

** increased risk of occult malignancy

Question 30

heterotopic ossification following injury?

Answer 30

myositis ossificans
metaplasia of skeletal mm –> bone after trauma
usually UE/LE

Question 31

MCC of death in scleroderma?

Answer 31

pulmonary sclerosis