Vacuum phenomenon in shoulder

Last revised by Dr Yuranga Weerakkody on 11 Dec 2021

Vacuum phenomenon in the shoulder refers to the presence of intra-articular gas in the shoulder joint. It is a very common occurrence, particularly in external rotation. This can cause circular or linear areas of low signal intensity on GRE MR images of the shoulder obtained with external rotation of the arm and represents small foci of intra-articular gas. Awareness of this potential pitfall and an understanding of the characteristic appearance and location of this collection of intra-articular gas may help prevent misdiagnosis of intra-articular loose bodies or chondrocalcinosis.

The presence of gas in a joint can occur in almost any joint, such as the sternoclavicular joint, where it may outline the intra-articular disc (see case 2).

See also

ADVERTISEMENT: Supporters see fewer/no ads

Cases and figures

  • Case 1: in left shoulder
    Drag here to reorder.
  • Case 2: vacuum phenomenon in the SCJ
    Drag here to reorder.
  • Case 3
    Drag here to reorder.
  • Updating… Please wait.

     Unable to process the form. Check for errors and try again.

     Thank you for updating your details.