Radiography: shoulder

• Accurate centering is essential when radiographing any joint.
• High resolution film-screen combinations are required.
• A grid is necessary when tissue thickness >10 cm.
• kV should not exceed about 60.
• Close collimation is essential to avoid scatter.
• If general anesthesia is not used, then sedation with analgesia is suggested.
• The film must include the whole joint, with soft tissues, must be correctly exposed and developed and free from movement blur and artefact.
• 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 shoulder.
• → Bony injury: fracture or dislocation Shoulder: luxation - traumatic .
• → Osteochondrosis Shoulder: osteochondrosis .
• → Bony neoplasia  , or soft tissue neoplasia Synovial cell sarcoma , invading bone.
• → Investigation of soft tissue injury.
• → Inflammatory, infectious or degenerative osteoarthrosis.
• → Congenital elbow luxation.

Advantages

• Non-invasive.
• Low cost and readily available.

Disadvantages

• Poor positioning can make subtle pathology impossible to detect.
• The presence of severe pain can make the procedure difficult in a conscious patient.
• Radiation exposure to patient/personnel.

Preparation

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

Procedure

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

Criteria for choosing test

• 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?

• Shows glenoid cavity and head of humerus.
• Demonstrates joint space.
• Shows soft tissue swelling and joint effusions.
• Can show calcification in tendons.
  Lateral oblique views may be necessary to visualize some osteochondritis dissecans (OCD) lesions.

• Necessary for minimum radiographic evaluation.
• Essential second view in cases of known or suspected fracture.
• Usually necessary in cases of dislocation.
• Useful to confirm or further assess osteochondrosis lesions.

• Most useful as part of a contrast arthrogram.
• May be useful in plain radiography to demonstrate calcification in the bicipital tendon, or bony change secondary to bicipital tendon damage.
• Also helpful to differentiate supraspinatous calcification from biceps tendon disease.

Other involvement

• Radiographer or veterinary nurse/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).
• Film ID system.

Ideal equipment

• High output X-ray machine.
• Rare Earth high definition screens.
• Automatic processing facilities.
• Film ID camera.

Minimum consumables

• X-ray film.
• Pharmaceuticals for chemical restraint.
• Film ID card or tape.

• 1-2 competent people.
• Sandbags.
• Foam wedges.
• Tying tapes.
• Positioning trough.

Step 1 - Lateral projection

• Place the patient in lateral recumbency on the side to be examined and immobilize.
• Use a sandbag to hold the contralateral limb out of the field caudally and dorsally.
• Use a tie to distract the affected limb well cranially to avoid superimposition of the scapulotium joint and thoracic structures and secure.
• Ensure the humerus is parallel to the film.
  Locate by palpation of the lateral aspect of the shoulder joint space.
• Center with a vertical beam directly through the joint space .
• Collimate to include the entire glenoid cavity, the soft tissues of the joint and the proximal third of the humerus .

Step 2 - Caudocranial projection

• Place the patient in dorsal recumbency in a trough and immobilize.
• Rotate the thorax slightly away from the affected side.
• Using a tie, extend the affected limb as far cranially as possible and secure.
• Adjust position of thorax and limb to ensure the joint is in the true craniocaudal position.
• Center the vertical beam through the joint space by palpation of the lateral aspect.
• Collimate to include the soft tissues of the joint and the proximal third of the humerus.

Step 3 - Cranioproximal-craniodistal (bicipital groove) projection

• Place the patient in sternal recumbency.
• Flex the shoulder and the elbow.
• Abduct the radius slightly so that it does not lie beneath the shoulder.
• Palpate the groove on the cranial aspect of the head of humerus and direct the beam tangentially through it.
• Collimate closely.

• Inadequate sedation.
• Incomplete studies (one view only) lead to inaccurate diagnosis.
• Poor technique: inaccurate positioning or collimation, wrong exposure factors, failure to label film.
• Poor processing.
• Equipment failure.

Refereed papers

• Recent references from PubMed and VetMedResource.
• Bradley K (2005) Radiography and radiology of the shoulder joint. UK Vet 10 (3), 52-55.