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Diagnostic Imaging II Final > AVN > Flashcards

Flashcards in AVN Deck (67):
1

What part of a long bone is likely to be affected by AVN?

Epiphysis (try to remember that suppurative infection SPARES the epiphysis)

2

What specific bone of the bone is more likely to develop AVN?

Femur head and humeral head

3

What are some synonyms for AVN?

Osteonecrosis, ischemic necrosis, osteochondrosis

4

When does epiphyseal necrosis become clinically evident?

With articular surface collapse

5

What is the clinical latent period of AVN?

Weeks to a year

6

What is the most common etiology category for AVN?

Spontaneous/idiopathic (others include surgery, trauma, alcoholism, corticosteroid usage)

7

What causes AVN?

Obstruction of extra- and intraosseous vessels by arterial embolism, venous thrombosis, traumatic disruption, or external compression

8

What is the time frame from initial infarction to healed deformity for AVN?

2-8 years

9

What causes of AVN fall under the etiology category of external vessel compression?

Trauma, steroids, infection, gaucher's disease, hyperlipidemia

10

What causes of AVN fall under the etiology category of vessel wall disorders?

RA, LE, radiation, polyarteritis nodosa

11

What causes of AVN fall under the etiology category of thrombo-embolic disorders?

Alcoholism, steroid, trauma, sickle-cell, caisson's

12

What is caisson's disease?

Decompression sickness

13

What are the four stages of AVN?

Avascular, revascularization, repair, deformity

14

What happens in the avascular stage of AVN?

Obliteration of epiphyseal blood supply, altered growth, altered cartilaginous growth

15

The altered cartilage seen with AVN can lead to what further condition?

DJD

16

Most X-ray findings of AVN are seen during which stage?

Revascularization

17

What is the term for when deposition occurs and new bone is deposited directly on dead bone therefore thickening the trabeculation and increasing bone density with AVN during the revascularization phase?

Creeping substitution

18

What is the radiographic sign that is definitive for AVN?

Crescent sign

19

What is the best procedure of choice to diagnose AVN?

MRI

20

During which phase of AVN can we see the mushroom deformity and sagging rope sign?

Repair/remodeling phase

21

What is the major factor in residual deformity following AVN?

How much compressive force is exerted on the necrotic bone during revascularization and repair phases

22

What is the trabecular pattern seen with AVN?

Mottled appearance: thickened irregular pattern traversing the necrotic areas usually in revascularization and repair phases

23

What is the name of the condition of AVN in the adult femoral head?

Chandler's disease

24

What is most likely the condition at hand with BILATERAL C-shaped lesions all over the distal femur and proximal tibia?

Metaphyseal/diaphyseal infarcts from AVN

25

What is the gender and age bias for Chandler's disease?

Males ages 30-70

26

What is the radiographic sign of a necrotic area that tends to be wedged or semilunar shaped with a central apex seen in Chandler's disease?

"Bite sign"

27

What are the radiographic signs of AVN?

Snow cap sign, crescent/rim sign, mushroom deformity, hanging rope sign

28

What imaging study is best to visualize AVN?

T1 MRI

29

What is the condition of AVN of the femoral capital epiphysis before closure?

Legg-Calve-Perthes Disease

30

What is the age and gender bias for Legg-Calve-Perthes Disease?

Males 4-8 YOA

31

Which ROM are commonly decreased with LCPD?

Abduction and internal rotation

32

Where is the referred pain in kids with LCPD?

Knee

33

What is unique about the joint space of LCPD?

INCREASED joint space (Kohler's teardrop)

34

What are the 3 major radiographic findings associated with LCPD?

Soft tissue swelling, small epiphysis, lateral displacement of ossification center

35

When gender has a worse prognosis with LCPD?

Females

36

What is osteochondritis dissecans?

Focal subchondral infarction of sub-articular bone

37

What is the age and gender bias for osteochondritis dissecans?

Males 11-20 YOA

38

What is the most common location for osteochondritis dissecans?

Knee

39

Osteochondritis will lead to what other condition later on?

DJD

40

What is the specific location of the knee commonly affected by osteochondritis dissecans?

Lateral margin of medial femoral condyle (intracondylar tunnel)

41

What is the term for osteochondritis dissecans of the capitulum of the elbow?

Panner's disease

42

What is the second most common location for osteochondritis dissecans besides the knee?

Distal tibia

43

What type of injury/alternative name is Osgood Schlatter's Disease?

AKA traction apophysitis

44

When Osgood Schlatter's Disease also involves the inferior pole of the patella, what is it then called?

Sindig-Larsen-Johanssen disease (ridiculous)

45

What is the gender and age bias for Osgood Schlatter's Disease?

Males 11-15

46

What is the mechanism of injury for traction apophysitits?

Repetitive microtrauma

47

When do the symptoms of localized pain, tenderness, and soft tissue swelling over the tibial tubercle with Osgood's go away?

By 18 YOA

48

What condition may be related to wearing high heels and involves AVN of the second metatarsal head?

Freiberg's disease

49

What's the gender and age bias for Freiberg's disease?

Females 13-18

50

What condition represents AVN of the lunate?

Kienbock's disease

51

What is the gender and age bias for Kienbock's disease?

Males 20-40

52

What usually causes AVN of the lunate?

Manual labor

53

Kienbock's disease is usually associated with what other radiographic finding?

Negative ulnar variance (75%)

54

What condition is AVN of the navicular bone?

Kohler's disease

55

Is Scheuermann's disease really AVN?

Probably not (likely trauma abnormality of the discovertebral junction)

56

What age group is usually affected by Scheuermann's disease?

Teens

57

What's another name for Scheuermann's?

Juvenile discogenic disease

58

What are the signs and symptoms of juvenile discogenic disease?

Chronic back pain, deformity, early DDD

59

How many contiguous vertebrae must be affected to diagnose juvenile discogenic disease?

3 Schmorl's nodes in a row

60

What appears to be the cause of juvenile discogenic disease?

Failure of embryologic vascular channels, centrum defects, and notochord clefts to disappear leaving endplate defects

61

How common is Scheuermann's disease?

20-40% of those presenting to MRI with back pain have it

62

What condition represents sclerosis and fragmentation of the calcaneal apophysis but it NOT technically a necrosis?

Sever's disease

63

What is Sever's disease without the presence of pain?

A normal varient (pain must be present for Sever's!)

64

Calcified medullary infarct could be confused with which bone cancer?

Enchondroma or chondrosarcoma

65

Calcified medullary infarct is usually associated with what other condition?

Arteriosclerosis

66

How can we differentiate between calcified medullary infarct of the proximal humerus and a chondrosarcoma?

Chondrosarcoma would present with pain; calcified medullary infarct would be asymptomatic

67

What does the hanging rope sign represent?

Healed AVN