Indication/Technique

Indication

X-rays of the wrist joint are requested frequently, particularly at the Emergency Assistance department. They are used primarily to confirm/exclude a fracture in the diagnostics of (rheumatoid) arthritis, and in functional hand and wrist symptoms.

 

 

 

Technique

By way of repetition of anatomical terminology: volar/palmar (palm of hand), dorsal (back of hand), ulnar (side of little finger) and radial (side of thumb). See also figure 1.

Palmar flexion / volar flexion vs. dorsal flexion & radial abduction vs. ulnar abduction.

Figure 1. Palmar flexion / volar flexion vs. dorsal flexion (dorsiflexion) & radial abduction vs. ulnar abduction.

When asked to confirm or exclude a fracture, the wrist should be imaged in at least two directions, as in any conventional image. A standard examination frequently consists of a posterior-anterior (PA) image and a lateral image. In a PA image, the shoulder is abducted to 90° and the elbow flexed to 90° (fig. 2). The wrist is placed flat on the X-ray plate.

Technique for PA image of the wrist.

Figure 2. Technique for PA image of the wrist.

A lateral image is obtained by turning the wrist with the thumb upwards (fig. 3).

Technique for lateral image of the wrist.

Figure 3. Technique for lateral image of the wrist.

To assess whether an image is purely lateral, consider the relationship between the capitate, pisiform and the scaphoid bones. The palmar cortex of the pisiform should be located centrally between the palmar cortex of the capitate and the scaphoid (fig. 4). Note: additional anatomy is discussed in the Normal Anatomy section.

Technique for purely lateral image of the wrist.

Figure 4. Technique for purely lateral image of the wrist. Ideally, the palmar cortex of the pisiform is located exactly between the palmar cortex of the capitate and the scaphoid (see top left). In the lower two positions, the image is not purely lateral.

Due to the complex shape of the scaphoid and the overlap of other carpal bones, a standard examination will not suffice. A so-called ‘scaphoid series’ can be obtained when a scaphoid fracture is suspected. Up to the present, there is no consensus in the literature what this series should include: both positions and number differ among hospitals/specialists. In most cases, the scaphoid is imaged in at least three directions.

Some common images include the PA image in ulnar deviation (fig. 5), 60° oblique image in ulnar deviation (fig. 6), fist image (fig. 7), lateral image (fig. 8).

X-wrist; technique for PA image in ulnar deviation

Figure 5. Technique for PA image in ulnar deviation (left wrist).

X-wrist; technique 60° oblique image in ulnar deviation.

Figure 6. Technique 60° oblique image in ulnar deviation (left wrist).

X-wrist; technique for fist image.

Figure 7. Technique for fist image (left wrist).

X-wrist; technique for lateral image

Figure 8. Technique for lateral image (left wrist).