Elbow Lateral

• Distal humerus in profile.
• Olecranon process of the ulna.
• Coronoid process of the ulna.
• Radial head and neck, partially overlapped by the coronoid.
• Open humeroulnar joint space.
• Anterior and posterior fat pads if effusion present.

• Verify patient identity using two identifiers.
• Remove watches, bracelets, and radiopaque items from the arm.
• Seat the patient at the end of the table.
• Flex the elbow 90 degrees, thumb-side up, wrist and hand in lateral.
• Drop the shoulder so humerus, elbow, and wrist sit in the same plane.

Lateral epicondyle. Elbow flexed 90 degrees, wrist and hand in true lateral, thumb side up.

Perpendicular to the elbow joint, entering at the lateral epicondyle.

kVp

60–75

mAs

3–6

SID

40" (102 cm)

Notes

90-degree flexion is essential: less flexion distorts the joint space.

• Elbow flexed at exactly 90 degrees.
• Open humeroulnar joint space, free of bony overlap.
• Olecranon process seen in profile.
• Three concentric arcs at the elbow: trochlea, capitulum, trochlear notch.
• Proximal radius and ulna superimposed at the joint.
• Collimation: 3 inches proximal and distal to the elbow joint.

1. 1 Flexion less than 90 degrees opens the joint and distorts anatomy.
2. 2 Raised shoulder tilts the humerus and closes the joint space.
3. 3 Hand rotated off lateral foreshortens the radial head.
4. 4 Failure to drop shoulder superimposes the humerus over the joint.

• Trauma evaluation for elbow fracture or dislocation.
• Posterior fat pad sign for occult radial head fracture.
• Olecranon and coronoid process assessment.
• Joint effusion evaluation.