AVN

Question 1

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

Answer 1

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

Question 2

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

Answer 2

Femur head and humeral head

Question 3

What are some synonyms for AVN?

Answer 3

Osteonecrosis, ischemic necrosis, osteochondrosis

Question 4

When does epiphyseal necrosis become clinically evident?

Answer 4

With articular surface collapse

Question 5

What is the clinical latent period of AVN?

Answer 5

Weeks to a year

Question 6

What is the most common etiology category for AVN?

Answer 6

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

Question 7

What causes AVN?

Answer 7

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

Question 8

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

Answer 8

2-8 years

Question 9

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

Answer 9

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

Question 10

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

Answer 10

RA, LE, radiation, polyarteritis nodosa

Question 11

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

Answer 11

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

Question 12

What is caisson’s disease?

Answer 12

Decompression sickness

Question 13

What are the four stages of AVN?

Answer 13

Avascular, revascularization, repair, deformity

Question 14

What happens in the avascular stage of AVN?

Answer 14

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

Question 15

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

Answer 15

DJD

Question 16

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

Answer 16

Revascularization

Question 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?

Answer 17

Creeping substitution

Question 18

What is the radiographic sign that is definitive for AVN?

Answer 18

Crescent sign

Question 19

What is the best procedure of choice to diagnose AVN?

Answer 19

MRI

Question 20

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

Answer 20

Repair/remodeling phase

Question 21

What is the major factor in residual deformity following AVN?

Answer 21

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

Question 22

What is the trabecular pattern seen with AVN?

Answer 22

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

Question 23

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

Answer 23

Chandler’s disease

Question 24

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

Answer 24

Metaphyseal/diaphyseal infarcts from AVN

Question 25

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

Answer 25

Males ages 30-70

Question 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?

Answer 26

"Bite sign"

Question 27

What are the radiographic signs of AVN?

Answer 27

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

Question 28

What imaging study is best to visualize AVN?

Answer 28

T1 MRI

Question 29

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

Answer 29

Legg-Calve-Perthes Disease

Question 30

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

Answer 30

Males 4-8 YOA

Question 31

Which ROM are commonly decreased with LCPD?

Answer 31

Abduction and internal rotation

Question 32

Where is the referred pain in kids with LCPD?

Answer 32

Knee

Question 33

What is unique about the joint space of LCPD?

Answer 33

INCREASED joint space (Kohler's teardrop)

Question 34

What are the 3 major radiographic findings associated with LCPD?

Answer 34

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

Question 35

When gender has a worse prognosis with LCPD?

Answer 35

Females

Question 36

What is osteochondritis dissecans?

Answer 36

Focal subchondral infarction of sub-articular bone

Question 37

What is the age and gender bias for osteochondritis dissecans?

Answer 37

Males 11-20 YOA

Question 38

What is the most common location for osteochondritis dissecans?

Answer 38

Knee

Question 39

Osteochondritis will lead to what other condition later on?

Answer 39

DJD

Question 40

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

Answer 40

Lateral margin of medial femoral condyle (intracondylar tunnel)

Question 41

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

Answer 41

Panner's disease

Question 42

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

Answer 42

Distal tibia

Question 43

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

Answer 43

AKA traction apophysitis

Question 44

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

Answer 44

Sindig-Larsen-Johanssen disease (ridiculous)

Question 45

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

Answer 45

Males 11-15

Question 46

What is the mechanism of injury for traction apophysitits?

Answer 46

Repetitive microtrauma

Question 47

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

Answer 47

By 18 YOA

Question 48

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

Answer 48

Freiberg's disease

Question 49

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

Answer 49

Females 13-18

Question 50

What condition represents AVN of the lunate?

Answer 50

Kienbock's disease

Question 51

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

Answer 51

Males 20-40

Question 52

What usually causes AVN of the lunate?

Answer 52

Manual labor

Question 53

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

Answer 53

Negative ulnar variance (75%)

Question 54

What condition is AVN of the navicular bone?

Answer 54

Kohler's disease

Question 55

Is Scheuermann's disease really AVN?

Answer 55

Probably not (likely trauma abnormality of the discovertebral junction)

Question 56

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

Answer 56

Teens

Question 57

What's another name for Scheuermann's?

Answer 57

Juvenile discogenic disease

Question 58

What are the signs and symptoms of juvenile discogenic disease?

Answer 58

Chronic back pain, deformity, early DDD

Question 59

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

Answer 59

3 Schmorl's nodes in a row

Question 60

What appears to be the cause of juvenile discogenic disease?

Answer 60

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

Question 61

How common is Scheuermann's disease?

Answer 61

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

Question 62

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

Answer 62

Sever's disease

Question 63

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

Answer 63

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

Question 64

Calcified medullary infarct could be confused with which bone cancer?

Answer 64

Enchondroma or chondrosarcoma

Question 65

Calcified medullary infarct is usually associated with what other condition?

Answer 65

Arteriosclerosis

Question 66

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

Answer 66

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

Question 67

What does the hanging rope sign represent?

Answer 67

Healed AVN