How to take a radiograph of a dog’s shoulder

Question 1

what are the common views used for radiographs of a canine shoulder?

Answer 1

Lateral
Caudo-cranial

Question 2

Describe the positioning for a lateral radiograph of the canine shoulder

Answer 2

The limb to be radiographed is pulled into extension using a rope tie (this also pulls the shoulder joint away from the neck soft tissues)
The upper limb is moved caudally out of the way with a rope tie
The neck is flexed dorsally and secured using a sandbag (this moves the cervical spine so it does not superimpose over the shoulder joint)
Place a foam pad under the chest to ensure the dog is parallel to the table and assist shoulder extension

Question 3

Describe the exposure and collimation for a lateral shoulder radiograph

Answer 3

The exposed area should include the distal 50% of the scapula and proximal 50% of the humerus
Collimate to include soft tissues cranial and caudal to shoulder
The centre of collimation should be the shoulder joint (just distal to the acromion)
Use L / R label

Question 4

What are common overlying tissues on lateral shoulder radiographs?

Answer 4

other limb, neck tissue, trachea, cervical spine

Question 5

Describe the positioning for a caudo-cranial radiograph of the shoulder

Answer 5

The dog is put in dorsal recumbency with the limb to be radiographed pulled into extension
The limb is pulled slightly away from the midline (approx. 5 degrees)
A sandbag may be use to push the head and neck slightly away from the limb
Aim to hold the long axis of scapula and humerus in line with each other

Question 6

Describe the centering and collimation of a caudo-cranial shoulder radiograph

Answer 6

Centre at the middle of the shoulder joint (just distal to the acromion)
Collimate to include the distal 50% of the scapula and proximal 50% of the humerus
Collimate to include the lateral and medial soft tissues
Use L/R label
A well positioned radiograph has the scapula and humerus in line with each other
Centring on the middle of the joint means there is good visualisation of the joint space

Question 7

What is the disadvantage of cranio-caudal radiographs of the shoulder?

Answer 7

can result in magnification distortion as it is difficult to get the shoulder close to the table

Question 8

What is this pathology?

Answer 8

Medial shoulder luxation (e.g. traumatic)

Question 9

Identify this pathology

Answer 9

Osteochondrosis (i.e. developmental):
- Loss of rounded contour of caudal surface of humeral head
- Radiolucent defect
- May have surrounding sclerosis
- May have calcified free body in joint

Question 10

Identify this pathology

Answer 10

Chronic shoulder arthrosis:
- Lots of new bone (osteophytes)
- Underlying cause often not evident

Question 11

Identify these radiographic findings

Answer 11