Acromioclavicular joint (AP weight-bearing view)

The acromioclavicular AP weight-bearing view is an additional interjection often performed to rule out displacement when it is suspected but not confirmed on the AP view

See also, acromioclavicular joint injuries.

Patient position

• the patient is erect holding a weight in the affected sides hand
• the midcoronal plane of the patient is parallel to the image receptor, in other words, the patient's back is against the image receptor
• the acromioclavicular joint of the affected side is at the center of the image receptor
• affected arm is in a neutral position by the patient side

Technical factors

• anteroposterior projection
• centering point
  • at the acromioclavicular joint
• collimation
  • superior to the skin margins
  • inferior to the humeral head
  • lateral to include the skin margin
  • medial to lateral third of the clavicle
• orientation  
  • landscape
• detector size
  • 18 cm x 24 cm
• exposure
  • 60-70 kVp
  • 10-15 mAs
• SID
  • 100 cm
• grid
  • yes (this can vary departmentally)

Image technical evaluation

• the acromioclavicular joint is central to the image with no overlap
• the image is appropriately annotated weight-bearing

Practical points

This projection can be very painful for a patient with an AC joint injury; it is highly recommended that everything is set up and positioned, so the last thing you do is hand the weights over.