Lecture 2

Question 1

What is a good general approach to orthopedic radiograph interpretation?

Answer 1

-check physeal closures in relation to patient age
-evaluate soft tissues
-evaluate periosteal margins and all cortices
-evaluate periarticular margins and subchondral bone
-evaluate joint capsular attachments
-evaluate joint spaces
-evaluate medullary cavities
-evaluate overall alignment and relationship of bones

Question 2

What are the Roentgen signs that will apply to each orthopedic dz?

Answer 2

-number
-size
-shape
-opacity
-location/position
-margination/contour

Question 3

What are the characteristics of soft tissue abnormalities?

Answer 3

-edema, hemorrhage, inflammation, or tumor infiltration causes loss of fascial plane visualization
-gas, swelling, or mineralizing causes change in opacity

Question 4

Which is normal and which is abnormal?

Answer 4

-top is normal; can see the fascial plane
-bottom is abnormal; fascial plane is no longer visible

Question 5

What can cause gas in soft tissues?

Answer 5

-open wound
-gas-producing organisms
-iatrogenic (needle puncture, post-op)

Question 6

What is abnormal in this radiograph?

Answer 6

areas of gas at the proximal aspect of the central bone and at the caudal margin of the central bone

Question 7

What are the common causes of soft tissue mineralization?

Answer 7

-metastatic mineralization
-dystrophic mineralization
-idiopathic
-neoplastic

Question 8

What is metastatic mineralization?

Answer 8

mineralization of normal tissue due to elevated serum calcium and/or phosphorus levels

Question 9

Where is metastatic mineralization seen?

Answer 9

in the walls of large blood vessels

Question 10

What is shown in this radiograph?

Answer 10

metastatic mineralization of the abdominal aorta and iliac arteries

Question 11

What is shown in this radiograph?

Answer 11

metastatic mineralization of the iliac vessels

Question 12

What is dystrophic mineralization?

Answer 12

mineralization of dead, degenerative, or devitalized tissues

Question 13

What is shown in these radiographs?

Answer 13

dystrophic mineralization at the level of an elbow joint repair

Question 14

What is shown in these radiographs?

Answer 14

dystrophic mineralization at the site of previous injection

Question 15

What is idiopathic mineralization?

Answer 15

mineralization of soft tissues not due to dystrophic or metastatic etiologies

Question 16

What is neoplastic mineralization?

Answer 16

mineral or bone production by a tumor; need histopath to confirm neoplastic vs dystrophic

Question 17

What is shown in this radiograph?

Answer 17

extra-skeletal osteosarcoma producing bone

Question 18

Which two types of swelling can be seen around or near a joint?

Answer 18

-intracapsular swelling
-extracapsular swelling

Question 19

What are the characteristics of intracapsular soft tissue swelling?

Answer 19

-enlargement of soft tissues within confines of the joint capsule
-swelling conforms to joint margins
-can occur with effusion or soft tissue proliferation

Question 20

What is shown in these radiographs?

Answer 20

intracapsular soft tissue swelling

Question 21

Which radiograph is normal and which is abnormal? Why?

Answer 21

Left: normal; infrapatellar fat pad is of normal size and placement
Right: abnormal; infrapatellar fat pad is displaced and compressed due to intracapsular swelling

Question 22

Which radiograph is normal and which is abnormal? Why?

Answer 22

Left: normal; deep fat caudal to the joint is in normal position
Right: abnormal; displacement of fascial planes caudal to joint due to intracapsular swelling; joint pouch buldges

Question 23

What is shown in these radiographs?

Answer 23

severe intracapsular swelling

Question 24

What are the characteristics of extracapsular soft tissue swelling?

Answer 24

-enlargement of soft tissues outside the joint
-may be diffuse or focal
-can occur with edema, hemorrhage, or inflammation
-can occur with ligament or tendon pathology
-can occur with neoplasia

Question 25

Which radiograph is normal and which is abnormal? Why?

Answer 25

Left: normal; thin patellar ligament, normal infrapatellar fat pad Right: abnormal; patella ligament desmopathy; ligament is enlarged and fat pat is compressed

Question 26

What are the potential responses of bone to injury/disease?

Answer 26

-new bone formation -lysis or reabsorption

Question 27

What are the different characteristics that should be assessed regarding osseous lesions?

Answer 27

-aggressive vs. non-aggressive -active vs. inactive -duration

Question 28

Why is it important to consider that radiographic changes lag behind clinical abnormalities?

Answer 28

-lytic changes take 5 to 7 days to be seen radiographically -productive changes take 10 to 14 days to be seen radiographically -extensive bone loss (30 to 60%) is required before detection on survey radiographs is possible

Question 29

What are the steps to evaluating osseous lesions?

Answer 29

-generalized vs focal -location and number of lesions -pattern of lysis -pattern of new bone production/periosteal reaction -cortical disruption -transition zone to normal bone -change in lesion appearance over time

Question 30

What is osteosclerosis?

Answer 30

increased bone opacity

Question 31

What is osteopenia?

Answer 31

generalized decreased bone opacity

Question 32

What is osteoporosis?

Answer 32

-loss of bone mass -quantity of bone is decreased -existent bone is of normal composition

Question 33

What is osteomalacia?

Answer 33

-loss of mineralization of bone matrix -quality of bone is decreased -increased percentage of non-calcified osteoid and/or insufficient mineralization of osteoid matrix

Question 34

What are the causes of generalized osteosclerosis?

Answer 34

-osteopetrosis -myelofibrosis -FeLV -dietary imbalances -idiopathic

Question 35

What are the causes of generalized osteopenia?

Answer 35

-congenital disease -metabolic disease -nutritional disease -disuse

Question 36

What is shown in this radiograph?

Answer 36

generalized osteosclerosis

Question 37

What is shown in this radiograph?

Answer 37

generalized osteopenia

Question 38

What are the Roentgen signs for generalized osteopenia?

Answer 38

-decreased bone opacity -cortical thinning -coarse trabeculation due to endosteal resorption -relative increase in opacity of cortical bone and vertebral endplates -intracortical bone loss/double cortical line -loss of lamina dura around teeth

Question 39

What is shown in these radiographs?

Answer 39

progression of generalized osteopenia after disuse

Question 40

Which radiograph is normal vs. abnormal? Why?

Answer 40

Top: abnormal; generalized osteopenia; relative increase in opacity of vertebral endplates Bottom: normal

Question 41

What is shown at the arrows in this radiograph?

Answer 41

double cortical line associated with generalized osteopenia

Question 42

What is lysis?

Answer 42

-focal/multifocal bone loss -typically due to trauma, infection, or tumor

Question 43

Which criteria are used to determine aggressive vs non-aggressive?

Answer 43

-location and number of lesions -pattern of lysis -pattern of new bone production -cortical disruption -transition zone to normal bone -change in lesion appearance over time

Question 44

How does axial vs appendicular skeleton location help predict type of lesion?

Answer 44

-primary bone tumors are most often appendicular -metastatic bone tumors often involve axial skeleton

Question 45

What are the differences between monostotic and polyostotic lesions?

Answer 45

*monostotic: -affect one bone -often primary bone tumors *polyostotic: -affect multiple bones -metastatic tumors -fungal osteomyelitis -juvenile/hematogenous osteomyelitis

Question 46

How does the location within the bone affect likely diagnosis?

Answer 46

-primary bone tumors are typically metaphyseal -metastatic tumors can be diphyseal or metaphyseal -fungal osteomyelitis is generally metaphyseal -juvenile bacterial osteomyelitis can be epiphyseal or metaphyseal

Question 47

What are the three patterns of lysis?

Answer 47

-geographic -moth-eaten -permeative

Question 48

What are the characteristics of geographic lysis?

Answer 48

-large, focal area -may appear expansile -well-defined; short transition to normal bone -least aggressive form of lysis

Question 49

What is shown in these radiographs?

Answer 49

geographic lysis

Question 50

What are the characteristics of moth-eaten lysis?

Answer 50

-multiple smaller areas of lysis -may become confluent to form a larger area -indistinct margins/long transition to normal bone -usually aggressive

Question 51

What is shown in these radiographs?

Answer 51

moth-eaten lysis

Question 52

What are the characteristics of permeative lysis?

Answer 52

-numerous small/pinpoint areas of lysis -can be in the medulla or cortex -margins are indistinct/long transition to normal bone -most aggressive pattern of lysis

Question 53

What is shown in these radiographs?

Answer 53

permeative lysis