Orthopedic radiographs are difficult to achieve even with a cooperative patient. The importance of diagnostic quality orthopedic radiography is emphasized while demonstrating how to achieve them using hands free techniques. Orthopedic studies are, for the most part, performed on systemically healthy yet painful patients. While we will discuss the benefits of sedation in another section, the use of analgesics and appropriate sedation is imperative to patient comfort and to achieve the best quality radiograph for accurate diagnosis.

In this section we will cover how-to demonstrations (video and description) on the most common orthopedic radiographs including:

• Pelvis.
• Stifle (TPLO vs. routine, CdCr vs. CrCd).
• Elbows (CrCd view individual joint, flexed laterals).
• Shoulder (where does the joint need to be?).
• Fractures, long bones and other miscellaneous orthopedic radiographs.

Each study will be discussed in detail including anatomic landmarks for collimation, visuals to demonstrate what is straight/crooked and tips on how to achieve a properly positioned orthopedic radiograph using hands-free techniques the first time. As many of these demonstrations are video based, we welcome questions and can repeat any videos for clarification.

During the videos we will discuss the importance of proper positioning:

• Joint centered, collimated and close to the table
• Anatomical landmarks
• Orthagonal views
• Exposure settings and algorithms
• Cropping/viewing orientation (digital)
• Properly identified radiographs with lead marker (OFA)

Positioning Techniques

Pelvis

Pelvis (Lateral)

• Position: Entire pelvis, center at acetabulum.
• Radiographic inclusion: Entire pelvis, lower leg positioned cranial.
• Diagnostic quality: Straight—transverse processes overlap, wings of ilium overlap.
• Adequate collimation and contrast/density.

Positioning Tips

• Place animal in lateral recumbency.
• Separate legs with lower leg pulled forward in a natural walking position, raise as needed.
• Use sandbags/straps to restrain front end, and wedge raise hind legs to create a square pelvis.

Pelvis (Extended V/D)

• Position: Entire pelvis to stifle. Centre at acetabulum.
• Radiographic inclusion: Wings of ilium to stifle joint (include entire joint).
• Diagnostic quality: Straight—ensure that the wings are of equal width, and obturator foramen are the same size/shape. Femurs should be the same size/length and parallel to each other. Patellas centered and condyles equal size. Ensure tail is out of the way. Adequate collimation and contrast/density.

Positioning Tips

• Often moderate to heavy sedation will be required.
• Place animal in VD with or without trough.
• It is ideal to have the pelvis close to the table (i.e., use trough only under thorax).
• Secure animal in VD position with sandbags/straps.
• Use foam wedge under pelvis.
• Extend hind legs with straps and place 1” tape around patellas to hold stifles inwards.
• Edge artifact: Edge of foam trough will be seen on x-ray, make sure area of interest is out of trough.

Elbow

Elbow (Lateral)

• Position: Distal humerus to proximal radius. Centre on joint.
• Radiographic inclusion: Entire elbow joint, include distal humerus to proximal radius.
• Diagnostic quality: Straight—only one epicondyle should be visible. Adequate collimation and contrast/density.

Positioning Tips

• Place patient in lateral recumbency, with a natural bend in elbow.
• Restrain top leg with strap or sandbag.
• A wedge may be required under shoulder, especially with large patients to allow the elbow to lay flat against the table.
• Sandbag hind legs and neck as required.

Elbow (Cranial/Caudal)

• Position: Distal humerus to proximal radius. Centre on joint.
• Radiographic inclusion: Entire elbow joint, include distal humerus to proximal radius.
• Diagnostic quality: Straight—ulna should overlap middle of humerus. Only one elbow per radiograph to ensure proper collimation and centering.

Positioning Tips

• Sedation often required.
• Place animal sternal (in or out of trough).
• Extend front leg forward using strap or sandbag.
• If patient is in a trough, often a foam wedge underneath the elbow will prevent the leg from slipping or twisting.
• Elevate head using block or trough if the patient is sedated.
• Rotate the elbow as needed to adjust straightness.

Stifle (Lateral)

• Position: Distal femur to proximal tibia. Centre on joint.
• Radiographic inclusion: Entire stifle joint, include distal femur to proximal tibia. Include stifle joint to hock for preoperative TPLO radiographs.
• Diagnostic quality: Straight—condyles overlap so only one is visible. Adequate collimation and contrast/density.

Positioning Tips

• Place patient in lateral recumbency.
• Secure the front end with sandbag/straps.
• Extend affected leg to create a 90-degree angle in stifle and hock, this can be achieved by using a strap just above the hock and pulling leg back.
• Placing a sandbag over or behind the foot can help create a 90-degree angle at the hock.
• A foam wedge under the down hip may be required to create a straight lateral.