GK

Question 1

a

Answer 1

Original – A – Cervical or Neck Bones (7 in number). B – Dorsal or Thoracic Bones (13 in number, each bearing a rib). C – Lumbar Bones (7 in number).D– Sacral Bones (3 in number). E – Caudal or Tail Bones (20 to 23 in number).

Skeleton of a dog: A – Cervical or Neck Bones (7 in number). B – Dorsal or Thoracic Bones (13 in number, each bearing a rib). C – Lumbar Bones (7 in number).D – Sacral Bones (3 in number). E – Caudal or Tail Bones (20 to 23 in number). 1 – Cranium, or Skull. 2 – Maxilla. 3 – Mandible, or Lower jaw . 4 – Atlas. 5 – Axis. 6 – Scapula, or Shoulder-blade. 7 – Spine of scapula. 8 – Humerus. 9 – Radius. 10 – Ulna. 11 – Phalanges. 12 – Metacarpal Bones. 13 – Carpal Bones or Wrist-bones. 14 – Sternum, or Breast-bone. 15 – Cartilaginous part of rib. 16 – Ribs (13 in number). 17 – Phalanges. 18 – Metatarsal Bones. 19 – Tarsal Bones. 20 – Calcaneus (os calcu). 21 – Fibula. 22 – Tibia. 23 – Patella, or Knee-cap. 24 – Femur. 25 – Ischium. 26 – Pelvis, or Hip-bone.

Question 2

When a white opacity is seen on a radiograph, what are the 5 most likely options?

Opacity is always relative to _____ structures or materials

Answer 2

CHANG 1. Cyst 2. Hemorrhage 3. Abscess 4. Neoplasia 5. Granulation

Known

Question 3

How many views to interpret orthopedic rads

Answer 3

At least 2

Question 4

Considerations for looking at bones?

Answer 4

1. Marination 2. Opacity 3. Geometry 4. Lesion distribution

Question 5

Considerations for joint rads?

Answer 5

1. Alignment 2. Width of joint space 3. Peri articulate findings 4. Lesion distribution

Question 6

Considerations for Soft Tissue Rads?

Answer 6

1. Thickness
2. Opacity

Question 7

After looking at Rads, the next steps are?

Answer 7

1. Reassess based on clinical, physical and lab findings 2. Prioritize list of differential DX 3. Make “follow-up” rads

Question 8

Marginatiion

Answer 8

The less distinct the bone Marin, the more active and aggressive the Dz. Assess how easily the bone margin can be traced with a pencil to determine it’s sharpness.

Question 9

Sharpness of bone margin is/ is not the same as shape of bone boarder

Answer 9

is not

Question 10

An irregular border does/does not equal an ill-defined margin and a smooth border does/does not equal a well defined margin.

Answer 10

Not Not

Question 11

Opacity definition

Answer 11

Characteristic of a material to block (attenuate or absorb) x-rays. The more opaque a material, the more x-rays are blocked and the whiter the material appears on the radiograph.

Question 12

Name the opacities of materials from least to most opaque.

Answer 12

1. Gas= black 2. Fat 2.5 Fluid 3. Soft tissue 4. Bone 5. Metal

Question 13

The inherent opacity of a material is related to it’s ______ Overall opacity of a material relates to it’s ______

Answer 13

Density (atomic number and degree of compaction) Thickness

Question 14

At least ____-____% of bone must be altered before a change is visible on rads

Answer 14

30-50

Question 15

Active bone destruction may be visible in ___-___ days on a rad?

Answer 15

5-7

Question 16

Active bone production may be visible in ___-____ days on rads?

Answer 16

10-14

Question 17

Causes for decreased bone opacity?

Answer 17

1. Osteopenia 2. Osteolysis

Question 18

Definition of Osteopenia? Reasons for seeing Osteopenia? 1. Bone to _____ ____ contrast is poor. 2. Vortices become _____ and _____ 3. Corgi medullary ______ is poor. 4. Trabecular in cancellous bone appear _____ and more _____ due to loss of fine bone structure. 5. A “_____ _____” may be visible due to intracorcortical resorption of bone.

Answer 18

“Too little bone” 1. Soft Tissue 2. Thin and Faint 3. Contrast 4. Larger and more porous (course trabecular pattern) 5. “Double cortical line”

Question 19

What 2 types of Osteopenia are there and which bones do they effect first?

Answer 19

1. General Osteopenia (due to hyperparathyroidism, nutrition deficiency) vertebrae>mandible>long bones 2. Regional osteopenia (limb immobilization) tends to be more severe in distal portion of limb

Question 20

What is Osteolysis?

Answer 20

An abnormal, localized area f active bone resolution caused by Dz. The pattern of Osteolysis reflects the aggressiveness if the disease process presents with less distinct bony margins, a longer zone of transition between moral and diseased bone, and more rapid rate of change on serial radiographs

Question 21

Osteolytic patterns (3) and their aggressiveness

Answer 21

1. Geographic pattern (least aggressive) 2. Moth-eaten pattern (more aggressive) 3. Permeative pattern (Most aggressive)

Question 22

Mixed patterns of Osteolysis are ________, especially with ________ diseases.

Answer 22

Common Aggressive As long as dz is unchecked, bone destruction will continue and bone margins will remain ill defined.

Question 23

What is the hemipelvis?

Answer 23

The bony pelvis comprises the two hemi-pelvis bones which are bound anteriorly at the pubic symphysis and posteriorly at the sacroiliac joints.

As with other anatomical bone rings if a fracture is seen in one place a careful check should be made for a second fracture, or for disruption of the pubic symphysis or sacroiliac joints.

Question 24

The most important determinators in the analysis of a potential bone tumor are:

Answer 24

The morphology of the bone lesion on a plain radiograph

1. Well-defined osteolytic

ill-defined osteolytic

Sclerotic

2. The age of the patient

It is important to realize that the plain radiograph is the most useful examination for differentiating these lesions.
CT and MRI are only helpful in selected cases.

Question 25

Most bone tumors are \_\_\_\_\_\_. The most reliable indicator in determining whether these lesions are benign or malignant is the ____ of ____ between the lesion and the adjacent normal bone (1). Once we have decided whether a bone lesion is sclerotic or _____ and whether it has a well-defined or ill-defined margins, the next question should be: how old is the patient? Age is the most important clinical clue. Finally other clues need to be considered, such as a lesion’s localization within the skeleton and within the bone, any periosteal reaction, cortical destruction, matrix calcifications, etc.

Answer 25

osteolytic zone of transition osteolytic

Question 26

What is the zone of transition?

Answer 26

In order to classify osteolytic lesions as well-defined or ill-defined, we need to look at the zone of transition between the lesion and the adjacent normal bone. **The zone of transition is the most reliable indicator in determining whether an osteolytic lesion is benign or malignant** ( The _zone of transition only applies to osteolytic lesions_ since sclerotic lesions usually have a narrow transition zone.

Question 27

What is a small zone of transition?

Answer 27

A small zone of transition results in a sharp, well-defined border and is a sign of slow growth. A sclerotic border especially indicates poor biological activity. In patients In patients \> 30years, and particularly over 40 years, despite benign radiographic features, metastasis or plasmacytoma also have to be considered On the left three bone lesions with a narrow zone of transition. Based on the morphology and the age of the patients, these lesions are benign. Notice that in all three patients, the growth plates have not yet closed.

Question 28

What is a wide zone of transition?

Answer 28

An ill-defined border with a broad zone of transition is a sign of aggressive growth (1). It is a feature of malignant bone tumors. There are two tumor-like lesions which may mimic a malignancy and have to be included in the differential diagnosis. These are infections and eosinophilic granuloma. Both of these entities may have an aggressive growth pattern.

Question 29

Infections and eosinophilic granuloma are exceptional because they are benign lesions which may seem malignant due to their _____ \_\_\_\_behavior. These lesions may have ill-defined margins, but cortical destruction and an aggressive type of periosteal reaction may also be seen. EG almost always occurs in patients Infections have to be included in the differential diagnosis of any bone lesion at any age.

Answer 29

aggressive biologic

Question 30

What is a periosteal reaction?

Answer 30

A periosteal reaction is a non-specific reaction and will occur whenever the periosteum is irritated by a malignant tumor, benign tumor, infection or trauma. There are two patterns of periosteal reaction: a benign and an aggressive type. The benign type is seen in benign lesions such as benign tumors and following trauma. An aggressive type is seen in malignant tumors, but also in benign lesions with aggressive behavior, such as infections and eosinophilic granuloma.

Question 31

What is a benign periosteal reaction?

Answer 31

Detecting a benign periosteal reaction may be very helpful, since malignant lesions never cause a benign periosteal reaction. A benign type of periosteal reaction is a thick, wavy and uniform callus formation resulting from chronic irritation. In the case of benign, slowly growing lesions, the periosteum has time to lay down thick new bone and remodel it into a more normal-appearing cortex.

Question 32

What is an aggressive periosteal reaction?

Answer 32

This type of periostitis is multilayered, lamellated or demonstrates bone formation perpendicular to the cortical bone. It may be spiculated and interrupted - sometimes there is a Codman's triangle. A Codman's triangle refers to an elevation of the periosteum away from the cortex, forming an angle where the elevated periosteum and bone come together. In aggressive periostitis the periosteum does not have time to consolidate. left: Osteosarcoma with interrupted periosteal rection and Codman's triangle proximally. There is periosteal bone formation perpendicular to the cortical bone and extensive bony matrix formation by the tumor itself. middle: Ewing sarcoma with lamellated and focally interrupted periosteal reaction. (blue arrows) right: Infection with a multilayered periosteal reaction. Notice that the periostitis is aggressive, but not as aggressive as in the other two cases.

Question 33

What is cortical distruction?

Answer 33

Cortical destruction is a common finding, and not very useful in distinguishing between malignant and benign lesions. Complete destruction may be seen in high-grade malignant lesions, but also in locally aggressive benign lesions like EG and osteomyelitis. More uniform cortical bone destruction can be found in benign and low-grade malignant lesions. Endosteal scalloping of the cortical bone can be seen in benign lesions like FD and low-grade chondrosarcoma. The images on the left show irregular cortical destruction in an osteosarcoma (left) and cortical destruction with aggressive periosteal reaction in Ewing's sarcoma.

Question 34

What is cortical ballooning?

Answer 34

Ballooning is a special type of cortical destruction. In ballooning the destruction of endosteal cortical bone and the addition of new bone on the outside occur at the same rate, resulting in expansion. This 'neocortex' can be smooth and uninterrupted, but may also be focally interrupted in more aggressive lesions like GCT. left: Chondromyxoid fibroma A benign, well-defined, expansile lesion with regular destruction of cortical bone and a peripheral layer of new bone. right: Giant cell tumor A locally aggressive lesion with cortical destruction, expansion and a thin, interrupted peripheral layer of new bone. Notice the wide zone of transition towards the marrow cavity, which is a sign of aggressive behavior.

Question 35

What is cortical distruction?

Answer 35

In the group of malignant small round cell tumors which include Ewing's sarcoma, bone lymphoma and small cell osteosarcoma, the cortex may appear almost normal radiographically, while there is permeative growth throughout the Haversian channels. These tumors may be accompanied by a large soft tissue mass while there is almost no visible bone destruction. The image on the left shows an Ewing's sarcoma with permeative growth through the Haversian channels accompanied by a large soft tissue mass. The radiograph does not shown any signs of cortical destruction.

Question 36

What kind of lesions will you find in the epiphysis?

Answer 36

Only a few lesions are located in the epiphysis, so this could be an important finding. In young patients it is likely to be either a chondroblastoma or an infection. In patients over 20, a giant cell tumor has to be included in the differential diagnosis. In older patients a geode, i.e. degenerative subchondral bone cyst must be added to the differential diagnosis. Look carefully for any signs of arthrosis.

Question 37

What kind of lesions will you find in the metaphysis?

Answer 37

Metaphysis NOF, SBC, CMF, Osteosarcoma, Chondrosarcoma, Enchondroma and infections. Differentiating between a diaphyseal and a metaphyseal location is not always possible. Many lesions can be located in both or move from the metaphysis to the diaphysis during growth. Large lesions tend to expand into both areas.

Question 38

What kind of lesions will you find in the diaphysis?

Answer 38

Diaphysis Ewing's sarcoma, SBC, ABC, Enchondroma, Fibrous dysplasia and Osteoblastoma. Differentiating between a diaphyseal and a metaphyseal location is not always possible. Many lesions can be located in both or move from the metaphysis to the diaphysis during growth. Large lesions tend to expand into both areas.

Question 39

How do you tell if the lesion is centric - eccentric - juxtacortical?

Answer 39

Centric in long bone SBC, eosinophilic granuloma, fibrous dysplasia, ABC and enchondroma are lesions that are located centrally within long bones. Eccentric in long bone Osteosarcoma, NOF, chondroblastoma, chondromyxoid fibroma, GCT and osteoblastoma are located eccentrically in long bones. Cortical Osteoid osteoma is located within the cortex and needs to be differentiated from osteomyelitis. Juxtacortical Osteochondroma. The cortex must extend into the stalk of the lesion. Parosteal osteosarcoma arises from the periosteum.

Question 40

What do you call mineralization w/in a bone lesion?

Answer 40

Calcifications or mineralization within a bone lesion may be an important clue in the differential diagnosis. There are two kinds of mineralization: a chondroid matrix in cartilaginous tumors like enchondromas and chondrosarcomsa and an osteoid matrix in osseus tumors like osteoid osteomas and osteosarcomas. Chondroid matrix Calcifications in chondroid tumors have many descriptions: rings-and-arcs, popcorn, focal stippled or flocculent. left: Enchondroma, the most commonly encountered lesion of the phalanges. middle: middle: Peripheral chondrosarcoma, arising from an osteochondroma (exostosis). right: Chondrosarcoma of the rib.

Question 41

What is osteoid matrix?

Answer 41

Osteoid matrix Mineralization in osteoid tumors can be described as a trabecular ossification pattern in benign bone-forming lesions and as a cloud-like or ill-defined amorphous pattern in osteosarcomas. Sclerosis can also be reactive, e.g. in Ewing’s sarcoma or lymphoma. left Cloud-like bone formation in osteosarcoma. Notice the aggressive, interrupted periosteal reaction (arrows). right Trabecular ossification pattern in osteoid osteoma. Notice osteolytic nidus (arrow).

Question 42

What constitute a multiple bone lesion?

Answer 42

Most bone tumors are solitary lesions. If there are multiple or polyostotic lesions, the differential diagnosis must be adjusted. Polyostotic lesions NOF, fibrous dysplasia, multifocal osteomyelitis, enchondromas, osteochondoma, leukemia and metastatic Ewing' s sarcoma. Multiple enchondromas are seen in Morbus Ollier. Multiple enchondromas and hemangiomas are seen in Maffucci's syndrome. Polyostotic lesions \> 30 years Common: Metastases, multiple myeloma, multiple enchondromas. Less common: Fibrous dysplasia, Brown tumors of hyperparathyroidism, bone infarcts. Mnemonic for multiple oseolytic lesions: FEEMHI: Fibrous dysplasia, enchondromas, EG, Mets and myeloma, Hyperparathyroidism, Infection.

Question 43

Name some spine lesions?

Answer 43

Hemangioma. Metastasis. Multiple myeloma. Plasmocytoma: vertebra plana. This 'Mini Brain' appearance of plasmacytoma in the spine is sufficiently pathognomonic to obviate biopsy (9).

Question 44

Name some foot lesions?

Answer 44

Question 45

What is the average number of bones of a dog/cat?

Answer 45

Dogs: 320 Cats: 244 50 vertebrae, 26 ribs, 8 sternebrae, 41 skull bones, 9 hyoid bones, 45 bones in each pectoral limbm 48 bones in each pelvic limb, 1 os penis

Question 46

Cortical (compact) bone forms the outer layer (cortex) of most bones (including all long bones), Rad appearance is dense, opaque, and \_\_\_\_\_\_. It makes up \_\_\_% of total bone mass.

Answer 46

homogenous 80

Question 47

Calcellous or trabecular bone are found in the ____ of long bones, in vertebrae and in flat bones. Rad appearance is \_\_\_\_\_\_\_, spongy, or porous. It makes up \_\_\_% of total bone mass. Bony trabeculae are surrounded by \_\_\_\_\_\_. It provideds nearly ___ times the surface area of cortical bone. It si capable of high rates of remodeling, especially during growth and \_\_\_\_\_.

Answer 47

end trabeculated (any of various rod-shaped structures that divide organs into separate chambers) 20 blood 10 disease

Question 48

What are the names of the different shape bones in the skeletal system?

Answer 48

Long Short Flat Irregular Sutural Sesamoid

Question 49

What bones are classified as LONG bones?

Answer 49

Humerus, Ulna, Radius, Metacarpals, Phalanges, Femur, Tibia, Fibula, Metatarsals.

Question 50

What bones are classified as SUTURAL bones?

Answer 50

Small irregular bones found between cranial bones.

Question 51

What bones are classified as IRREGULAR bones?

Answer 51

Vertebrae, Sphenoid, Ethmoid, Facial bones.

Question 52

What bones are classified as SHORT bones?

Answer 52

Carpals, Tarsals

Question 53

What bones are classified as FLAT bones?

Answer 53

Frontal, Parietal, Occipital, Temporal, Hip, Ribs, Scapulae, Sternum.

Question 54

What bones are classified as SESAMOID bones?

Answer 54

shaped like a sesame seed - Patella

Question 55

What are the seven parts of a long bone?

Answer 55

1. **_Physis_**- 2. **_Diaphysis_** 3. **_Metaphysis_** 4. **_Epiphysis_** 5. **_Apophysis_** 6. **_Periosteum-_** 7. **_Endosteum_**-

Question 56

Physis is what?

Answer 56

(growth plate, epiphyseal cartilage, or epipyseal plate). Present in immature animals. Separates the metaphysis from epiphysis or apophysis. composed of hyaline cartilage (appears as a less opaque band) In mature animals, the physis is absent and the metaphysis and epiphysis blend together.

Question 57

What is ithe diaphysis?

Answer 57

("between physis")- middle portion or shaft of a long bone. Consists of cortical bone surrounding a less opaque medullary cavity.

Question 58

What is the Metaphysis?

Answer 58

("next to physis")- Wider portion located at either end of diahysis. contains cancellous bone. Functions as a zone of transformation where cancellous metaphyseal bone becomes cortical diaphyseal bone. (called the cut back zone)

Question 59

What is the epiphysis?

Answer 59

("upon physis")- Rounded end that supports articular cartilage. Compsed of cancellous bone and a layer of dense subchondral bone.

Question 60

What is the Apophysis?

Answer 60

("away or apart from physis")- A non articular epiphysis. Provides a prominence of bone for attachment of tendons and ligaments. Examples: femoral greater trochanter, tibial tuberosity, humeral greater tubercle.

Question 61

What is the Periosteum?

Answer 61

Completely covers all long bones except articular areas that are covered by cartilage). It consist of two layers: a) inner layer (cambium) produces bone via osteoprogenitor cells. b) outer layer is fibrous connective tissue. It is attached to the cortex by Sharpey's fibers. It blends continuously with tendons and ligaments at their attacements. Supplies nerves and blood vessels to underlying bone. It is responsible for circumferential growth of immature long bones. It provides the healing reponse when bone is damaged.

Question 62

What is the endosteum?

Answer 62

Lines the medullary cavities of bones. It is similar to periosteum but thinner.

Question 63

Dog body references

Answer 63

Question 64

What are the different types of bone classifications?

Answer 64

Question 65

Name the different types of collagen in making of bones?

Answer 65

Question 66

What are Sharpy's fibers?

Answer 66

Question 67

Illustration of a typical long bone showing the location of cancellous bone ("trabecular bone" on the image).

Answer 67

Question 68

Light micrograph of a decalcified histologic specimen of cancellous bone showing its bony trabeculae (pink) and marrow tissue (blue).

Answer 68

Question 69

There are 2 types of bone marrow, what are they and what defines them?

Answer 69

_There are two types of bone marrow:_ **Red, or hematopoietic** Produces red blood cells, white blood cells and platelets Gets its red color from the hemoglobin in the erythroid cells Hematopoietic cells mature and migrate into sinusoids to enter the circulation when they are formed. Highly vascular **Yellow, or stromal** Produces fat, cartilage, and bone Gets its yellow color from the carotenoids in the fat droplets in the high number of fat cells Paucity of vasculature