Lame - Diagnostic imaging - bone

Question 1

What can greatly change radiographic evaluation?

Answer 1

Positioning
Exposure/processing

Question 2

What are some signs you can see in soft tissue that suggest disease?

Answer 2

Swelling
Muscle wastage
Foreign material
Gas
Effusion

Question 3

What joint can you tell if there is an effusion of the joint capsule?

Answer 3

Stifle

Question 4

How can you tell if there is an effusion of the stifle joint capsule?

Answer 4

Radiolucent lines of fat running down the fascial planes on the caudal aspect of the stifle - if these are pushed backwards then it suggests distention of the joint capsule
Also fat in between the patella and the joint capsule - radiolucent unless squashed

Question 5

What is an example of when alignment can help to diagnose a condition on radiograph?

Answer 5

In cranial cruciate rupture, when the midpoint of the femoral condyle doesnt align with the midpoint of the tibia bumps - cranial draw

Question 6

What is the outline of the bone called?

Answer 6

The cortex

Question 7

What can be mistaken for a fracture in the cortex of a bone?

Answer 7

Nutrient foramen - well defined lucency extending through one cortex of the bone into the medulla
This is normal

Question 8

What can you assess of the cortex to determine if it is normal?

Answer 8

The outline - is it continuous
Thickness of cortex

Question 9

What is the outside and the inside of the cortex called?

Answer 9

Periosteal surface - outside of bone
Endosteal surface - inside, next to medulla

Question 10

What can you assess of the medulla on radiograph?

Answer 10

Integrity of trabeculae
Changes in opacity

Question 11

What is a normal change in opacity of the medulla?

Answer 11

The medulla in the mid-diaphysis of long bones is naturally more radiolucent - blacker, seems more see through

Question 12

What is a condition that affects long bones and is shown in the medulla on radiograph?

Answer 12

Panosteitis

Question 13

What is panosteitis?

Answer 13

Self limiting disease in young large breed dogs that affects the long bones causing shifting lameness between one leg and the other

Question 14

What does panosteitis look like on radiograph?

Answer 14

Uneven opacity with some areas of long bone more radioopaque and some more radiolucent - patchy

Question 15

What can you assess of articular surfaces on radiograph to determine disease?

Answer 15

Contours of surfaces - is end of bone shaped normally
Subchondral bone - normal opacity, any defects indicating osteochondrosis
Congruity - alignment normal, subluxation present

Question 16

What are physes?

Answer 16

Growth plates

Question 17

What can look like fractures in young animals?

Answer 17

Physes - are open in young animals
Can look like fractures, but often arent
They can fracture however - need to know how to differentiate this

Question 18

What can cause confusion in cases of osteochondrosis?

Answer 18

Condition is bilateral but animal may only be lame on one leg

Question 19

How can you tell there is bone loss?

Answer 19

Opacity of bone reduces - more like soft tissue
Thinning of cortices - outer bone
Thinning of medullary trabeculae

Question 20

How much mineral has to be lost to be radiographically apparent?

Answer 20

40%
So will be severe if can see on radiograph

Question 21

What can cause focal/multifocal bone loss?

Answer 21

Infection - osteomyelitis
Neoplasia
Trauma

Question 22

What can cause diffuse bone loss?

Answer 22

Disuse
Nutritional/metabolic cause

Question 23

What is an example of a disease causing nutritional bone loss?

Answer 23

Secondary hyperparathyroidism - calcium phosphorus imbalance leading to mineral resorption from bone

Question 24

What can cause increased bone production?

Answer 24

Trauma
Neoplasia
Infection - osteomyelitis
Craniomandibular osteopathy

Question 25

What is smooth pattern of distribution in bone production likely to be caused by?

Answer 25

Benign chronic lesion

Question 26

What is spiky/spicular pattern of distribution in bone production likely to be caused by?

Answer 26

Active aggressive neoplastic lesion Infection

Question 27

What are features of an aggressive lesion causing increased bone production?

Answer 27

Spicular spiky edges - no well defined margins Long zone of transition - not a discrete edge Mixed production and destruction of new bone - patchy

Question 28

When might there be both periosteal and endosteal thickening/bone production?

Answer 28

Callus

Question 29

How can you tell if it is bone formation compared to dystrophic calcification of surrounding soft tissues?

Answer 29

If there are trabeculation to the bone being produced If it is attached to the periosteum

Question 30

What is the appearance of a benign bone lesion?

Answer 30

Well marginated Short zone of transition Smooth thinned cortices Expansile but no cortical destruction

Question 31

What is craniomandibular osteopathy? What does it occur in?

Answer 31

New bone formation on the cranium, tympanic bullae and mandible Occurs in young small breed dogs - terriers

Question 32

What is hypertrophic osteopathy?

Answer 32

New bone production on the periosteum of limb bones in response to a space occupying lesion in the thorax or abdomen Mechanism is unknown

Question 33

What is calcinosis circumscripta?

Answer 33

A build up of mineralisation in the soft tissues around pressure points eg. shoulders, hock

Question 34

How can you differentiate calcinosis circumscripta from bone formation?

Answer 34

Take radiographs in multiple different planes - will see it is not attached to the bones

Question 35

What features can you look at to help to describe and classify different fractures?

Answer 35

Orientation Number and position of fragments Involvement of growth plates Involvement of articular surfaces

Question 36

What are some different orientations of fractures?

Answer 36

Transverse - straight across bone Oblique Spiral

Question 37

What is a comminuted fracture?

Answer 37

Divides the bone into multiple fragments

Question 38

What is a simple fracture?

Answer 38

Divides bone into two pieces

Question 39

What does it mean if the bone is distracted in a facture?

Answer 39

Fragments moved apart

Question 40

What does it mean if the bone is impacted in a facture?

Answer 40

Shortened a bone

Question 41

What does it mean if the bone is overriding in a facture?

Answer 41

The fragments are displaced and overlapping

Question 42

What is the classification for physial/growth plate fractures?

Answer 42

Salter-Harris classification

Question 43

What is the convention for describing the position of the fracture?

Answer 43

Describe the distal part of the fracture relative to the proximal part eg. radius has moved cranially and proximally relative to the humerus

Question 44

Why is aging a fracture important?

Answer 44

Will be useful if determining if it was a pathological fracture - underlying pathology in the bone

Question 45

How do you age a fracture?

Answer 45

Look at the margins of the fracture

Question 46

What does a recent fracture look like when aging fractures?

Answer 46

Recent - margins are well defined

Question 47

What does the bone look like after 7-10 days when aging fractures?

Answer 47

Rounder, less well defined ends with some bone loss

Question 48

What happens after 10-14 days in fracture aging?

Answer 48

Periosteal new bone trying to form a callus over fracture site

Question 49

What happens after 4-6 weeks in fracture aging?

Answer 49

Bony union and then remodelling

Question 50

What is luxation?

Answer 50

Complete separation of the joint surfaces

Question 51

What is subluxation?

Answer 51

Displacement of joint surfaces but partial contact still remains

Question 52

What are two causes of luxations/subluxations?

Answer 52

Traumatic Congenital

Question 53

What causes nutritional secondary hyperparathyroidism?

Answer 53

Low calcium or high phosphorus in the diet

Question 54

What does nutritional secondary hyperparathyroidism cause?

Answer 54

Mineral resorption of bone - generalised decrease in bone opacity Thinning of the cortices - cause fractures Normal growth plates

Question 55

What types of fractures can nutritional secondary hyperparathyroidism cause?

Answer 55

Complete or folding

Question 56

What is different about nutritional secondary hyperparathyroidism caused by renal failure?

Answer 56

Skull is most affected - rubber jaw Teeth look like they are floating Similar radiographic appearance

Question 57

What causes rickets?

Answer 57

Lack of vitamin D

Question 58

What are the radiological features of rickets?

Answer 58

Affects the physes - widened physes Flares metaphyses Overall mineralisation often normal

Question 59

What animals tend to get hypervitaminosis A?

Answer 59

Cats fed a diet of mostly liver

Question 60

What does hypervitaminosis A cause?

Answer 60

Periosteal new bone formation in the cervical spine, spine and limb joints Can cause fusion of bone Wont correct after diet corrected