Sternoclavicular joint (serendipity view)

The serendipity view is a specialized radiographic projection utilized in the setting of suspect dislocations of the sternoclavicular joint. The projection is seldom used in departments with functioning computed tomography, but still utilized in postoperative imaging.

Indications

The serendipity view is often requested in the context of significant trauma that can result in sternoclavicular joint dislocation or medial end clavicular fractures. Furthermore, this projection can be requested when following up on already known sternoclavicular injuries in the setting of outpatient appointments.

Patient position

• supine on the radiographic examination table 

Technical factors

• axial projection
• centering point
  • at the level of the sternoclavicular joint with a 40-degree cephalic angle 
• collimation
  • laterally to include the medial third of both clavicles 
  • inferiorly to include the sternoclavicular joints and part of the manubrium 
  • superiorly to include the entirety of the sternoclavicular joint
• orientation  
  • landscape
• detector size
  • 24 cm x 18 cm
• exposure
  • 60-70 kVp
  • 10-30 mAs
• SID
  • 100 cm
• breathing
  • suspended expiration
• grid
  • yes (this can vary departmentally)

Image technical evaluation

• both sternoclavicular joints are clearly evident
• sharp bony detail 
• no evidence of motion 
• use of appropriate angle evident via clear bony structures free from excessive distortion, an example of too much angle and inadequate collimation can be seen in figure 1
• normal anatomy
  • the medial ends of the clavicle are equal distance apart in the same horizontal plane 
• posterior dislocation
  • the medial end of the dislocated clavicle will be inferior to the mean horizontal plane of the sternoclavicular joint
• anterior dislocation
  • the medial end of the dislocated clavicle will be superior to the mean horizontal plane of the sternoclavicular joint (figure 2)

Practical points

• this projection is rarely practised; consequently, it is regarded as an advanced radiographic investigation. The most challenging part of the examination is ensuring your patient is supine on the correct portion of the table to allow adequate room to line up the detector to the tube.

Siehe auch:

• Articulatio sternoclavicularis
• Schulteraufnahme nach Rockwood