Elbow Xray Positioning - Lateral Projection - Lateromedial

Griswold gave two reasons for the importance of flexing the elbow 90 degrees:

• the olecranon process can be seen in profile
• the elbow fat pads are the least compresed

It must be realized that in partial or complete extension the olecranon process elevates the posterior elbow fat pad and simulates joint pathology.

Image Receptor: 8 x 10 inches single or 24 x 30 cm divided.

Patient Position:

Let patient seat at the end of radiographic table low enough to place the humerus and elbow joint in the same plane.

Part Position:

• From the supine position, flex the elbow 90 degress and place the humerus and forearm in contact with the table.
• Center the image receptor to the elbow joint. Adjust the elbow joint so that its long axis is parallel with the long axis of the forearm. On patients with muscular forearms, elevate the wrist to place the forearm parallel with the image receptor.
• Adjust the image receptor diagonally to include more of the arm and forearm.
• To obtain a lateral projection of the elbow, adjust the hand in the lateral position and ensure that the humeral epicondyles are perpendicular to the plane of the image receptor.
• Shield gonads

Central ray:

Perpendicular to the elbow joint, regardless of its location on the image receptor.

Structure shown:

The lateral projection demonstrates the elbow joint, distal arm, and proximal forearm.

Evaluation Criteria:

• The following should be clearly demonstrated:
• Open elbow joint centered to the central ray.
• Elbow flexed 90 degrees
• Superimposed humeral epicondyles
• Radial tuberosity facing anteriorly
• Radial head partially superimposing the coronoid process
• Olecranon process seen in profile
• Bony trabeculation and any elevated fat pads in the soft tissue at the anterior and posterior distal humerus and the anterior proximal forearm. 

When injury to the soft tissue around the elbow is suspected, the joint should be flexed only 30 or 35 degrees. This partial flexion does not compress or stretch the soft structures as does the full 90 degree lateral flexion.