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.
• Anterior fat pad, normally a lucent teardrop; posterior fat pad only when a joint change displaces it.

• WARNING: with possible spinal injury or severe trauma, do not attempt to move the patient; do not rotate a severely injured part or remove splints (Bontrager). Merrill's: do not attempt true AP or lateral positioning of a severely injured limb; take two projections 90 degrees apart, moving it as little as possible, and move the IR and tube if the patient cannot reach the position.
• Verify patient identity using two identifiers.
• Remove watches, bracelets, and radiopaque items from the arm.
• Seat the patient at the end of the table with the elbow flexed 90 degrees.
• Align the long axis of the forearm with the long axis of the IR, elbow joint centered to the CR and the IR.
• Drop the shoulder so the humerus and forearm are on the same horizontal plane.
• Rotate the hand and wrist into a true lateral, thumb side up, interepicondylar plane perpendicular to the IR.

Mid-elbow joint, about 1 1/2 inches (4 cm) in from the easily palpated posterior surface of the olecranon process. Elbow flexed 90 degrees, wrist and hand in true lateral, thumb side up.

Perpendicular to the IR, directed to the mid-elbow joint.

kVp

70

mAs

DR 1.4 / CR 2.5

SID

40" (102 cm)

Notes

90-degree flexion is essential: in partial or complete extension the olecranon elevates the posterior fat pad and can simulate joint pathology. Exception: 30 to 35 degrees for certain soft tissue injuries, only when specifically indicated. Sample technique: DR 1.4 / CR 2.5 mAs at 70 kVp, 40 in SID, for an 8 cm part. Adjust for your equipment.

kVp and mAs are sample values. Use caution when applying them in your department.

• Elbow flexed 90 degrees (30 to 35 degrees only when soft tissue injury is specifically indicated).
• Exposure shows the soft tissue margins of the elbow fat pads: the anterior pad normally, the posterior pad only if displaced.
• Olecranon process seen in profile.
• Three concentric arcs (trochlear sulcus, capitulum and trochlea ridges, trochlear notch); epicondyles superimposed.
• About half of the radial head superimposed by the coronoid process.
• Olecranon process seen in profile.
• Three concentric arcs (trochlear sulcus, double ridges of the capitulum and trochlea, trochlear notch); epicondyles superimposed.
• CR and center of the collimation field at the midpoint of the elbow joint.

1. 1 Elbow not flexed 90 degrees, so the fat pads cannot be judged.
2. 2 Shoulder not dropped, so the humerus and forearm are not on the same horizontal plane.
3. 3 Hand not in true lateral (thumb not up): the interepicondylar plane is not perpendicular to the IR.
4. 4 CR not centered to the mid-elbow joint.
5. 5 Elbow not flexed 90 degrees: the olecranon elevates the posterior fat pad, which can mimic pathology.
6. 6 Hand and wrist not in true lateral, so the epicondyles are not superimposed.

• Trauma evaluation for elbow fracture or dislocation.
• Visible posterior fat pad, which suggests a joint pathologic process.
• Olecranon process assessment.
• Joint effusion evaluation.