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Flashcards in Bone and CT Deck (67):
1

Bones of the axial and appendicular skeleton + base of the skull are formed via what process?

Endochondral ossification

Cartilage model (chondrocytes) → Woven bone (Osteoclasts/blasts) 

Later remodel to Lamellar bone

2

When do you see woven bone in adults?

After fx and Pagets disease

3

What bones are formed by membranous ossification?

Calvarium and facial bones - no cartilage model

4

What do osteoblasts differentiate from?

Mesenchymal stem cells - secrete collagen and catalyze mineralization

5

What do osteoclasts differentiate from?

Monocytes/Mφ

6

Chronic ↑PTH has what effect on bone?

Catabolic - osteitis fibrosa cystica

7

Estrogen has what effect on bone?

⊣ apoptosis in osteoblasts

→ apoptosis in osteoclasts

8

What causes Achondroplasia?

Constit active FGFR3 - inhibit chondrocyte proliferation

Sporadic - adv. paternal age

some AD inheritance

9

S/S of Achondroplasia?

Failure of longitudinal long bone growth (endochondral ossification)

Short limbs, large head

10

How do you diagnose osteoporosis?

DEXA ≤ -2.5

Normal bone mineralization and lab values

11

What are indications of type 1 (post-men) osteoporosis?

Femoral neck fx & distal radius fx

12

How do you treat osteoporosis?

Bisphosphonates

PTH - intermittant

SERMs

Denosumab - anti-RANKL

13

SS of Osteopetrosis?

Thickened dense bones prone to fx

Pancytopenia and EM hematopoiesis

Cranial nerve impingement and palsies

 

14

What drives the symptoms of osteopetrosis? What can cure it?

Mutations in carbonic anhydrase II
Osteoclasts can't make enough acid

BMT - OC are from monocytes

15

What effect does vitamin D deficiency have on bone?

↓ mineralization/calcification of osteoid

*hyperactivity of osteoblasts - ↑ALP

16

What is the only lab value that is incresaed in Paget disease of bone?

ALP

Ca, PO4 and PTH are nomral

17

What are other symptoms of Paget disease of bone?

↑Hat size and Hearing loss

18

What isthe most common site for AVN?

Femoral head - insufficiency of medial circumflex femoral a.

19

What causes AVN?

Trauma, high-dose corticosteroids, alcoholism, sickle cell

20

What are the 2 benign primary tumors of bone?

Giant Cell tumor

Osteochondroma 

21

A 25 yo man has a tumor in the epiphyseal end of a long bone with a soap bubble appearance on XR - what is it?

Giant cell tumor - locally aggressive, benign 

22

Osteochondroma

Mature bone w/ cartilaginous cap, rarely transforms

Males < 25

23

What is the 2nd most common 1˚ malignant tumor of bone? What does imaging show?

Osteosarcoma

codman triangle or sunburst on XR

 

24

Who gets an osteosarcoma and where does it occur?

Bimodal - 10-20 and >65

Metaphysis of long bones, often around knee

25

What predisposes to osteosarcoma?

Pagets disease of bone

Bone infarcts

Radiation

Familial retinoblastoma

Li-Fraumeni syndrome

26

Who gets Ewing Sarcoma? Where does it occur?

Boys < 15

Diaphysis of long bones, pelvis, scapula, and ribs

27

Ewing Sarcoma

Small blue malignant tumor

Onion skin appearance of bone

t(11;22)

28

Where do chondrosarcomas occur? Who get them?

Pelvis, spine, scapula, humerus, tibia, or femur (diaphysis)

Men 30-60 yo

29

An expansive glistening mass within the medullary cavity is a description of what?

Chondrosarcoma

30

How do you distinguish between osteoarthritis and RA?

OA: Pain after use or at end of day

RA: Morning stiffness > 30min, improve w/ use

31

What is RA mediated by?

Type III and IV hypersensitivity

Cytokines

32

What antibodies can be seen in RA? What predisposes to it?

⊕ rheumatoid factor (IgG)

Anti-cyclic citrullinated peptide Ab = more specific

HLA-DR4

 

33

What are examples of disease modifying agents used to treat RA?

MTX

Sulfasalazine

TNF-α inhibitors

34

S/S of Sjogren syndrome

Xerophthalmia = ↓ tear producition → corneal damage

Xerostomia = ↓ saliva prodcution → dental caries

Bilateral parotid enlargement

35

What might a unilateral parotid enlargement in a patient with Sjogren syndrome suggest?

MALT-oma 

36

What antibodies are seen in Sjogren? (2)

Antinuclear antibodies

SS-A = anti-Ro

SS-B = anti-La

37

What is the most common cause of gout?

Underexcretion of uric acid - 90%

EtOH consumption - metabolites compete w/ uric acid for excretion

38

Gout

Precipitation of monosodium urate crystals

Needle-shaped ⊖birefringent (yellow under parallel)

Red, swollen, painful joint

Tophus in external ear, olecranon bursa, achilles tendon

39

How do you treat an acute gout attack? Chronic?

Acute = NSAID, glucocorticoids, colchicine

Chornic = allopurinol, febuxostat

40

What types of crystals are seen in pseudogout?

Calcium pyrophosphate

Basophilic rhomboid, weakly ⊕ birefringent (blue when parallel)

41

What diseases might be associated with pseudogout?

Hemochromatosis

HyperPTH and Hypo PTH

42

What are the 3 most common causes of infectious arthritis? In sexually active people?

S. aureus, Streptococcus, N. gonorrhoeae

N. gonorrhoeae

43

What are the 4 seronegative spondyloarthropaties - what are they associated with?

PAIR - HLA-B27

Psoriatic arthritis

Ankylosing spondylitis

IBD - w/ ankylosing spondylitis or peripheral arthritis

Reactive Arthritis

44

Psoriatic Arthritis

Dactyitis (sausage fingers)  

Pencil in cup

45

Ankylosing Spondylitis

CID of spine and sacroiliac joints

Ankylosis - stiff spine - bamboo spine

Uveitis

Aortic Regurgitation

46

Reactive Arthritis (Reiter syndrome)

Conjunctivis, urethritis, arthritis

Post GI - Shigella, Salmonella, Yersinia

Post Chlamydia

47

What is the classic presentation of Lupus (SLE)

Rash, joint pain, and fever in a female of reproductive age and African descent.

48

What antibodies are sensitive for SLE? Drug-induced lupus?

ANA - sensitive not specific

Antihistone = drug induced 

49

What antibody is both specific for SLE and associated with poor prognosis?

Anti-dsDNA 

Poor prognosis associated with renal disease

50

Anti-Smith antibodies

Specific for SLE

against snRNPs

51

Lupus nephritis (type III) can cause which 2 diseases?

Nephritic: Diffuse proliferative glomerulonephritis

Nephrotic: Membranous glomerulonephritis

52

What do you use to treat SLE?

NSAIDs, steroids, immunosuppressants, hydroxychloroquine

53

Widespread noncaseating granulomas in a black female is indicative of what?

Sarcoidosis

54

What 2 enzymes are elevated in Sardoidosis?

ACE

1α-hydroxylase (Mφ)

55

Polymyalgia rheumatica

Pain/stiffness in hips/shoulders + fever, malaise, and weight loss

↑ESR, CRP, normal CK

Responds to low-dose corticosteroids

56

How do you treat fibromyalgia?

Regular exercise

Antidepressants - TCA, SNRI

Anticonvulsant

57

What is polymyalgia rhematica associated with?

Temporal (giant cell) arteritis

58

Endomysial inflammation with CD8 T cells is characterisitic of what?

Polymyositis: progressive symmetrical proximal weakness

**shoulders**

59

Perimysial inflammation and atrophy with CD4 Tcells?

Dermatomyositis: Malar rash, "shawl and face" rash, heliotrope rash, Gottron papules, mechanic's hands

↑ risk of occult malignancy

60

↑CK, ⊕ANA, ⊕anti-Jo-1, ⊕anti-SRP, and ⊕anti-Mi- antibodies are indicative of what?

Polymyositis/Dermatomyositis

61

How can you differentiate Mysathenia Gravis and Lambert-Eatin myasthenic syndrome?

MG = worsens w/ use, improves with AChE inhibitor

Lambert-Eaton = improves with use, no response to AChEi

62

Myasthenia Gravis

Auto-Antibody to postsynaptic ACh receptor

Ptosis, diplopia, weakness

Associated w/ thymoma, thymic hyperplasia

63

Lambert-Eaton myasthenic syndrome

Auto-antibodies to presynaptic Ca channel → ↓ACh release

Proximal muscle weakness, autonomic symptoms (dry mouth, impotence)

Small cell lung CA

64

Myositis ossificans

Metaplasia of sk. muscle to bone following trauma

65

Scleroderma

Excessive fibrosis and collagen deposition throughout body

66

Diffuse Scleroderma

Widespread skin involvement, rapid progression, early visceral involvement

Anti-Scl-70 antibody - DNA-topo I

67

Limited scleroderma

Limited skin - fingers and face only

CREST - antiCentromere antibody

Calcinosis

Raynaud phenomenon

Esophageal dysmotility

Sclerodactyly

Telangiectasia