Radiography: elbow

• A high definition film-screen combination is required.
• A grid is not required.
• kV should not exceed about 50.
• Soft tissues should be included.
• General anesthesia or heavy sedation is required.
• The film should be correctly exposed and developed, and free from movement blur and artifact.
• The anatomical marker must be clearly visible, along with the patient's identification, the date, and the name of the hospital or practice.

• An important diagnostic aid in determining the cause of lameness arising from the elbow.
• Fracture Fracture: overview, especially of the humeral condyles.
• Dislocation Elbow: traumatic luxation.
• Joint effusion with other causes.
• Investigation of soft tissue injury.
• Neoplasia, but unusual site.

Advantages

• Non-invasive.
• Straightforward.

Preparation

• Dependent upon the method of chemical restraint (GA or sedation).

Procedure

• 10 to 15 minutes, or longer, dependent upon skill of radiographer.

Criteria for choosing test

Is the examination appropriate?

• Can you make the diagnosis without it?
• Can it tell you what you need to know?
• Will your management be affected by the radiological findings?

Choosing the right projections

Lateral

• Standard projection. Shows joint spaces and soft tissues.

Craniocaudal

• Essential in addition to lateral view in cases of suspected fracture and to localize lesions detected on lateral view.
  For optimum demonstration of the proximal radius and ulna use positioning method option 1. For optimum demonstration of the distal humerus, use option 2.

Other involvement

• Radiographer, or Technician carrying out radiography.

Minimum equipment

• X-ray machine.
• Cassettes with high definition screens.
• Processing facilities.
• Immobilization and positioning aids: sandbags, foam wedges, tying tapes.
• Protective clothing (lead-rubber aprons).

Ideal equipment

• High output X-ray machine.
• Rare earth high definition screens.
• Automatic processing facilities.

Minimum consumables

• X-ray film.
• Pharmaceuticals for chemical restraint.

• One to two competent people.
• Sandbags.
• Foam wedges.
• Tying tapes.
• Positioning trough.
• Positioning blocks.

Step 1 - Lateral

• Position the patient in lateral recumbency on the side to be examined and immobilize.
• Use a sandbag or tie to hold the contralateral limb caudally and dorsally away from the field.
• Use padding under the shoulder and carpus as necessary to ensure that the humerus and the radius and ulna are parallel to the film. This is essential to ensure a true lateral position for the elbow.
• The elbow should be flexed to approximately 90 degrees.
• Palpate the humeral epicondyle, which will be more prominent on the lateral aspect.
• Center the vertical beam at this point .
• Collimate to include the distal third of the humerus, the proximal third of the radius and ulna, and the soft tissues around the joint   .

Step 2 - Craniocaudal: option 1

• Place the patient in sternal recumbency.
• Extend the affected limb as far cranially as possible and secure.
  If the elbow and shoulder are not in full extension it will be very difficult to maintain an unrotated craniocaudal position of the elbow.
• Place the thin end of a 15 degree foam wedge between the elbow and the film. This will facilitate achieving the true craniocaudal position.
• Rotate the limb until the point of the elbow is palpable beneath the middle of the cranial aspect, ie until the elbow is in a true craniocaudal position .
• Center the vertical beam through the "crease" of the elbow.
• Collimate to include the distal third of the humerus, the proximal third of the radius and ulna, and the lateral skin surfaces .

Step 3 - Craniocaudal: option 2

• Place the patient in dorsal recumbency, with a positioning trough at hip level, and immobilize.
• Extend the affected limb caudally and secure with a tie.
  Elevate the film and the elbow on blocks so that the humerus lies flat.
• Rotate the thorax to achieve a true craniocaudal position of the limb.
• Center the vertical beam through the "crease" of the elbow.
• Collimate to include the distal third of the humerus, the proximal third of the radius and ulna, and the skin surfaces lateral to the joint.

• Inadequate sedation.
• Poor technique: inaccurate positioning or centering, wrong exposure factors.
• Poor processing.
• Equipment failure.

Refereed papers

• Recent references from PubMed and VetMedResource.
• Allan G S (2000) Radiographic features of feline joint diseases. Vet Clin North Am Small Anim Pract 30 (2), 281-302 PubMed.