Lameness (Yr 4)

Question 1

what is a major artifact that could happen when radiographing the musculoskeletal system?

Answer 1

geometric distortion

Question 2

what is geometric distortion?

Answer 2

structures towards the edge of the collimation are not truly parallel to the beams so it will be distorted (lengthened or shortened) on the image

Question 3

what are the rontgen (radiographic) signs?

Answer 3

number
size
shape (and margination)
location
opacity

Question 4

what are the three specific assessments to make looking at musculoskeletal radiographs?

Answer 4

soft tissue (swelling/loss)
bones
joints

Question 5

what assessments should be made about the bones in musculoskeletal cases?

Answer 5

alignment, shape, length
periosteal reaction, cortical lysis, defects
endosteal/medullary changes
physes (growth plates)

Question 6

what can cause reduced size of soft tissues?

Answer 6

atrophy (focal) - chronic lameness, neurogenic, fibrosis/scaring
weight loss (general)

Question 7

what can cause a focal increase in soft tissue size?

Answer 7

trauma
abscess/seroma
granuloma
neoplasia

Question 8

what can cause a diffuse increase in soft tissue?

Answer 8

oedema
cellulitis/vasculitis
diffuse neoplasia

Question 9

what are the parts of a long bone?

Answer 9

epiphysis, metaphysis, diaphysis

Question 10

what are the layers of long bone?

Answer 10

periosteum
cortex
endosteum
medulla

Question 11

what changes can be seen with bones on radiographs?

Answer 11

reduction in opacity
periosteal reaction (bone surface)

Question 12

how can focal bone loss (lysis) be categorised on radiographs?

Answer 12

geographic
moth-eaten
permeative

Question 13

what is geographic bone lysis?

Answer 13

homogenous reduction in opacity

Question 14

what is moth-eaten bone lysis?

Answer 14

lots of coalescing areas of lysis

Question 15

what is permeative bone lysis?

Answer 15

slow lysis of a particular area

Question 16

what is the least to most aggressive categories of bone lysis (loss)?

Answer 16

geographic (least)
moth-eaten
permeative (most)

Question 17

how can periosteal reaction (bone surface) be described from inactive/benign to active/aggressive?

Answer 17

smooth
rough
brush border
palisading
spicular
sunburst
amorphous

Question 18

what do you need to critically assess when looking at joints?

Answer 18

soft tissue swelling
joint space width
subchondral bone opacity
oestophyte/enthesophytes
periarticular mineralisation

Question 19

what is the only joint that you can definitively say from a radiograph if there is effusion within the joint or soft tissue swelling around it?

Answer 19

stifle (due to infrapatellar fat pad)

Question 20

how can cartilage around a joint be visualised on radiographs?

Answer 20

contrast studies (or use another imaging modality)

Question 21

what are some causes of subchondral bone changes?

Answer 21

osteochondrosis (main one)
aseptic necrosis (femoral head)
septic arthritis
erosive arthritis
trauma (avulsion fracture)
soft tissue neoplasia
osseous cyst like lesions
osteoarthritis (if severe)

Question 22

what are some radiographic changes seen with osteoarthritis?

Answer 22

soft tissue swelling/effusion
periarticular new bone (at predictable sites)
subchondral sclerosis
narrowed joint space
(evidence of primary disease process)

Question 23

what are the predilection sites for oesteochondrosis?

Answer 23

caudal aspect of humeral head
medial part of humeral condyle
lateral femoral condyle
medial trochlear ridge of talus

Question 24

what are the predilection sites for osteosarcomas?

Answer 24

proximal humerus
distal radius/ulna
distal femur
proximal tibia