The elbow X-ray examination is requested frequently. At the Emergency Assistance department, it is used primarily to demonstrate/exclude a fracture. Other referrals to this examination come from e.g. GPs or orthopedists. A frequently asked question is whether there is osteoarthritis in the elbow joint.
A standard series includes an anteroposterior (AP) image and a lateral image. Additionally, a radial head – capitellum image can be made.
The arm is in exorotation (palm of the hand pointing upward) and in full extension. The back of the arm should be in contact with the plate (fig. 1). The joint is then imaged from above. A good image shows the elbow joint, plus 1/3 of the distal humerus and 1/3 of the radius/ulna.
Figure 1. Technique for AP image of the elbow.
For a purely lateral image, the shoulder should be at the same level as the elbow. Importantly, the medial side of the entire arm should be in contact with the table. Sometimes a sand bag may prove helpful. The hand is turned vertically, the hand palm pointing toward the patient (fig. 2). The X-rays will pass through the joint parallel to the humeral epicondyles. A good image will show the elbow joint with about 1/3 of the distal humerus and 1/3 of the proximal radius/ulna.
Figure 2. Technique for lateral image of the elbow.
Radial head – capitellum image
For improved visualization of the radial head, a separate radial head image can be made, e.g. in dubious/subtle fractures. The elbow is positioned as in the lateral image. It is then imaged under a 45-degree angle, rather than cranial as in a purely lateral image (fig. 3).
Figure 3. Technique of a radial head image.