Radiographic Techniques: Distal Humerus & Proximal Forearm

Distal Humerus AP Projection (Acute Flexion)

• Patient positioned at the end of the radiographic table with the elbow fully flexed.
• The image receptor (IR) is centered proximal to the humerus' epicondylar area.
• The long axes of the arm and forearm should be parallel to the long axis of the IR.
• Central ray is perpendicular to the humerus, approximately 2 inches superior to the olecranon process.
• Collimation should include the proximal half of the forearm and 1 inch beyond the olecranon process and sides of the elbow.
• The projection superimposes the proximal forearm and distal humerus.
• The olecranon process should be clearly visible.

Proximal Forearm PA Projection (Acute Flexion)

• Center the flexed elbow joint at the corner of the IR.
• The long axes of the superimposed forearm and arm should be parallel to the long axis of the IR.
• Central ray is angled perpendicular to the forearm entering approximately 2 inches distal to the olecranon process.
• This position superimposes the proximal forearm and distal humerus.
• The elbow joint should be more open than in a distal humerus projection.

Distal Humerus AP Projection (Partial Flexion)

• Patient seated low enough to place the entire humerus on the same plane.
• Support the elevated forearm.
• If possible, supinate the hand.
• The IR is placed under the elbow, positioned over the condyloid area of the humerus.
• Central ray is perpendicular to the humerus, traversing the elbow joint. Angling the central ray distally may be necessary based on the degree of flexion.
• The radiation field is adjusted to 3 inches proximal and distal to the elbow joint, and 1 inch on the sides.
• The distal humerus is shown in cases where the elbow cannot be fully flexed.

Proximal Forearm AP Projection (Partial Flexion)

• Patient positioning is similar to the previous projection.

• The elbow joint is centered on the IR.

• The long axis of the superimposed forearm and arm should be parallel to the long axis of the IR.

• Central ray angled perpendicular to the flexed forearm, entering approximately 2 inches distal to the olecranon process.

• Superimposing the proximal forearm and distal humerus.

Radial Head Lateral Projection

• Position the patient at the radiographic table, with the hand supinated.
• Ensure the patient is positioned high enough to permit the dorsal surface of the forearm to rest on the table.
• Central ray perpendicular to the elbow joint and long axis of the forearm; passing through the midpoint of the elbow.
• Flex the elbow 90 degrees, centering the joint on the IR and placing it laterally.
• Four different positions—1st exposure (hand supinated), 2nd (hand lateral), 3rd (hand pronated), and 4th (hand in extreme internal rotation) —are recommended for different views.
• The exposed area covers 3 inches proximal and distal to the elbow joint.

Radial Head and Coronoid Process Axiolateral Projection

• Patient positioned with the humerus, elbow, and wrist joints in the same plane.
• Pronate the hand and flex the elbow either 90° (radial head) or 80° (coronoid process).
• Center the IR on the elbow joint.
• Position with the patient supine: elevate the distal humerus on radiolucent sponge, with the IR vertically centered on the elbow joint.
• Ensure epicondyles are perpendicular.
• Gradually flex the elbow to 90° (radial head) or 80° (coronoid process).
• Turn the hand to position the palmar side medially.
• Central ray, angled to the shoulder: 45° towards the radial head (seated) or horizontally cephalad at 45° to the radial head (supine)
• Central ray, angled away from the shoulder: 45° to the coronoid process (seated), or horizontally caudad at 45° to the coronoid process (supine).
• Projected view shows an open elbow joint between the radial head and capitulum, and between the coronoid process and trochlea.