Test 2: 16 large animal xray

Question 1

5 steps to interpret if you have good large animal xray

Answer 1

1. Adequate quality study
2. Adequate number of views
3. Identification of abnormalities
4. Recommendations
5. Interpretation of abnormalities
   * Make diagnosis vs list differential diagnoses
   * Determine significance

Question 2

how many views for large animal

Answer 2

4 need obliques to see small details

Question 3

changes indicate bone damage

shape:—
size: —

Answer 3

shape: contour abnormality, malalignment, subluxation

size: soft tissue swelling

roentgen signs: size, shape, opacity, margination, number

Question 4

changes indicate bone damage

opacity:—
margination: —

Answer 4

opacity: increased or decreased bone density

margination: irregular periosteal proliferation, subchondral irregularity/bone loss

roentgen signs: size, shape, opacity, margination, number

Question 5

soft tissue and — have the same opacity

Answer 5

fluid

Question 6

4 ways to describe bone abnormality

Answer 6

• what is the abnormality
• where is it
• one bone or multiple bones
• localized, diffuse, multifocal

Question 7

disorder of the connective tissues between bones and tendons or ligaments

Answer 7

enthesopathy

Question 8

why is medullary cavity less opaque then cortical bone

Answer 8

fatty= less opaque= less white

Question 9

geographic lysis can be caused by

Answer 9

bone cyst
subcondral injury

Question 10

moth eaten or permeative lysis can be caused by

Answer 10

more aggressive destruction

osteomyelitis
neoplasia

Question 11

osteophytosis

Answer 11

“bone spurs”, are outgrowths of bone tissue that form around damaged joints

Question 12

Answer 12

severe osteophytosis
(bone spur)
periarticular new bone

Question 13

— bone pathology is likely to be painful no matter the location

Answer 13

“Aggressive”

rapidly changing= normally caused by sepsis or neoplasia

Question 14

— bone pathology may or may not cause lameness depending on its location and other regional factors

Answer 14

”Benign”

Question 15

Answer 15

joint space has thinned= loss of cartilage

Question 16

based on location is that a cyst?

Answer 16

no

that is where collateral ligament attaches= enthesis

need to know attachment points to rule in and out diagnosis

if this circle was on the long bone it would prob be a bone cyst

Question 17

Answer 17

well defined but irregular periarticular proliferation

caused by injury to intracapsular soft tissue

Question 18

Answer 18

this is where joint capsule attaches

proliferation of periosteum secondary to inflammation of joint capsule

Question 19

Answer 19

subchondral bone plate thickening/ trabecular sclerosis

Question 20

Answer 20

demineralization/lysis of the subchondral bone plate

Question 21

xrays with osteoarthritis will show

Answer 21

• Subchondral sclerosis +/- lucency —
• Joint effusion/capsular thickening (soft tissue swelling)
• Periarticular new bone formation
• Joint space narrowing (cartilage loss)

Question 22

what shows osteoarthritis

Answer 22

• Subchondral sclerosis +/- lucency —
• Joint effusion/capsular thickening (soft tissue swelling)
• Periarticular new bone formation
• Joint space narrowing (cartilage loss)

Question 23

why does septic arthritis cause lameness but little xray changes in early stages

Answer 23

need 30% loss to be able to see on xray

can have issues before we can see it on xray

early signs:
* joint effusion/capsular thickening
* subchondral lysis

late signs
* can look like end stage osteoarthritis

Question 24

early stage septic arthritis/physitis will show

Answer 24

— Joint effusion/capsular thickening (often marked)
— Subchondral lysis

Question 25

how to tell osteoarthritis from late stage septic arthritis

Answer 25

repeat xrays in 10-14 days aggressive (septic) will show a change in xray

Question 26

chip fractures vs chips

Answer 26

**chip fractures**: caused from chronic repetitive trauma- osteochondral fragmentation **chip**: developmental issue - osteochondritis dissecans (OCD)- young horse

Question 27

how to tell osteochondral fragmentation from OCD?

Answer 27

**osteochondral fragmentation**: from chronic repetitive trauma: like a racehorse in training **OCD**: osteochondritis dissecans: is genetic, usually young horses the chips will be in different spots and need to look at signalment

Question 28

what are the 5 roentgen signs

Answer 28

roentgen signs: size, shape, opacity, margination, number

Question 29

What is the body part/region included? Which of the images or sets of images is abnormal and which set is normal (A vs B)?

Answer 29

stifle B

Question 30

Describe the lesion(s) on the abnormal set of images using orthopedic Roentgen signs Include names of the bones and anatomical directions (e.g. dorsal vs palmar, medial vs lateral, proximal vs distal, if applicable)

Answer 30

Ill-defined osteolysis of proximolateral tibial epiphysis and metaphysis Moderate adjacent lateral soft tissue swelling ## Footnote roentgen signs: size, shape, opacity, margination, number

Question 31

Is the primary lesion radiographically aggressive or benign? Would you expect this lesion to cause lameness?

Answer 31

aggressive: ill defined margins yes →aggressive lesions and associated with joint (subchondral/epiphyseal location)

Question 32

What is the body part/region included? Which of the images or sets of images is abnormal and which set is normal (A vs B)?

Answer 32

R metatarsophalangeal joint (aka RH fetlock) A

Question 33

Which of the images or sets of images is abnormal and which set is normal (A vs B)? Describe the lesion(s) on the abnormal set of images using orthopedic Roentgen signs Include names of the bones and anatomical directions (e.g. dorsal vs palmar, medial vs lateral, proximal vs distal, if applicable)

Answer 33

Well-defined ovoid lucency within distal third metatarsal diaphysis, just proximal to proximal sesamoid bones, medial parasagittal to midline Thin rim surrounding sclerosis

Question 34

Is the primary lesion radiographically aggressive or benign? Would you expect this lesion to cause lameness?

Answer 34

benign (well-defined lucency, the surrounding sclerosis suggests this was not a rapid process (bone has time to remodel over time) No/unlikely (benign lesion and not associated with joint)

Question 35

Answer 35

Question 36

Answer 36

Question 37

where is a horse's knee and what is the equivalent human joint

Answer 37

knee is the front leg of horse between ulna and radius and the carpal joints equal to wrist of human

Question 38

where is the hock of a horse

Answer 38

back leg- after tibia and fibula and before cannon bone equal to ankle in a human

Question 39

a horse's cannon bone is --

Answer 39

metacarpals/ metatarsals is below the hock( back leg) or the knee(front leg) and befor the fetlock (metacarpal-phalangeal joint)