Clements-Nakayama Method - Trapezium

PA Axial Oblique Projection - Trapezium

Clements-Nakayama Method

Fracture of the trapezium are rare. However, if undiagnosed these fractures can lead to functional difficulties. In certain cases the anticular surfaces of the trapezium should be evaluated to treat the osteoarthritic patient.

Image receptor: 8 x 10 inches, lengthwise

Patient Position

With the patient seated at the end of the radiographic table, place the hand on the IR in the lateral position.

Part Position:

• Place the wrist in the lateral position, resting on the ulnar surface over the center of the IR.
• Place a 45 degree sponge wedge against anterior surface, and rotate the hand to come in contact with the sponge.
• If the patient is able to achieve ulnar deviation, adjust the image receptor so that the long axis of the image receptor and the forearm align with the central ray.
• If the patient is unable to comfortably achieve ulnar deviation, align the straight wrist to the image receptor and rotate the elbow end of the image receptor and arm 20 degrees away from the central ray.
• Shield gonads.

Centray ray:

• Central ray is angled 45 degrees distally to enter the anatomic snuffbox of the wrist and pass through the trapezium.

Structure shown:

The radiograph will clearly demonstrate the trapezium and its articulations with the adjacent carpal bones. The articulation of the trapezium and scaphoid is not demonstrated on this image.

Evaluation Criteria:

• The following should be clearly demonstrated:
• Trapezium projected free of the other carpal bones with the exception of the articulation with the scaphoid.