Wrist (clenched fist view)

The clenched fist view is an additional projection used to evaluate suspected widening of the scapholunate interval, often performed bilaterally it is a functional view that requires the patient to clench both hands. 

Patient position

• patient is seated in front of the table 
• both hands are placed palm down on the image receptor as close together as possible
• shoulder, elbow, and wrist should all be in the transverse plane, perpendicular to the central beam
• the wrist and elbow should be at shoulder height which makes radius and ulna parallel (lowering the arm makes radius cross the ulna and thus relative shortening of radius)
• the patient can choose to hold something in their hands (a pencil) to squeeze down on, as long as a constant pressure can be maintained

Technical factors

• bilateral posteroanterior projection
• centering point
  • between the two hands 
• collimation
  • laterally to the skin margins of both hands
  • distal to the midway up the metacarpals
  • proximal to the include one-quarter of the distal radius and ulna
• orientation  
  • landscape
• detector size
  • 18 cm x 24 cm
• exposure
  • 50-60 kVp
  • 3-5 mAs
• SID
  • 100 cm
• grid
  • no

Image technical evaluation

• both wrists are equal distance from the middle of the image, with side markers on each side
• only minor superimposition of the metacarpal bases
• articulation between the distal radius and the ulna is open or has little superimposition
• concavity of the metacarpal shafts is equal ¹

Practical points

Often this projection is performed as part of a follow-up investigation, the patient may be suffering from chronic pain and find this view challenging. It is important to explain to the patient what they need to do and why they are doing it. Often it needs to be conveyed the examination may be a little painful, and this is due to the nature of the injury. 

After explaining the why and how, ensure everything is set up before asking them to make a tight fist, this will ensure the minimum time the patient needs to undergo any discomfort.