Cartilage interface sign

Cartilage interface sign, also referred to as double cortex sign, refers to the sonographic presence of a thin markedly hyperechoic line at the interface between the normally hypoechoic hyaline articular cartilage of the humeral head and an abnormally hypoechoic supraspinatus tendon. This arises due to the marked difference in acoustic impedances of the two tissues at the interface 1. The sign indicates the presence of partial or complete supraspinatus tear with fluid replacing the fibers and has been shown to be 100% specific 2.  However, it is not often present and has a low sensitivity for supraspinatus tear, around 30% 2.

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Article information

rID: 14197
Section: Signs
Synonyms or Alternate Spellings:
  • Double cortex sign

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Cases and figures

  • Case 1: cartilage interface sign
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