Radiography: stifle

• Digital radiography or conventional radiography using mammography films provide better definition.
• The contralateral stifle should be included for comparison.
• The soft tissues surrounding the joint should be included.
• General anesthesia or heavy sedation is commonly required, particularly if a fracture is present. Alternatively, calm rabbits may allow positioning just covering its eyes, dimming the lights and using sandbags and tape.
• 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.
  Print off the Owner factsheet on Xray and ultrasound  to give to your clients.

Uses

• Joint effusion, luxation or soft tissue swelling.
• Degenerative articular changes.
• Fracture Limb fracture (distal femur, proximal tibia, patella) .
• Neoplastic bone disease .

Advantages

• Non-invasive.
• Straightforward.

Time required

Preparation

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

Procedure

• 10-15 min, or longer, dependent upon skill of radiographer.

Decision taking

Criteria for choosing test

• Any lameness, abnormal gait, paresis or paralysis of the hind limbs.

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.
• Good for demonstrating joint effusion.
• Better visualization of patella and fabellae .

Craniocaudal

• Essential to have a second view to fully access fractures, luxations, degenerative changes, etc .
• Necessary for full assessment of neoplastic conditions.

Caudocranial (alternative to craniocaudal)

• This is arguably preferable to a craniocaudal projection as the stifle does not extend to a full 180°. The beam geometry (oblique rays) will help to achieve a good projection through the joint and of the proximal tibia only when the beam is directed from the caudal aspect.
• The caudocranial is definitely preferable where there is abnormal restriction of stifle extension.
• The position can be tricky to achieve and is normally only possible with good chemical restraint.
• In extreme cases of positioning difficulty the caudocranial projection can be carried out with a horizontal beam.