mri knee meniscus degeneration maceration flap tear extrusion meniscocapsular separation radedasia


A few more MRI Meniscus abnormalities such as meniscus maceration, flap tears, extrusion and meniscocapsular separation.

menisco capsular sepration knee radiology radedasia

  • Meniscocapsular separation is a separation of the attachment of the external margin of the body of the medial meniscus from the Posterior Oblique ligament.

  • Normally they are tightly attached and there should be no high signal between them.

  • Here we see a rim of high signal where the two have separated.

meniscus flap tear displaced knee radiology radedasia


  • A flap tear of the meniscus is a horizontal type tear where one side of the meniscus rotates away.


  • Most commonly its in the medial meniscus body.


  • One fragment is displaced out of the joint to lie between the sMCL and tibia or femur.

meniscus extrusion tibia medial plateau margin knee radiology radedasia


  • Meniscal extrusion is when part of the meniscus is displaced from the joint.


  • This is measured on a coronal scan.


  • Displacement of the meniscus more than 2.5 - 3mm from the edge of the medial tibial plateau indicates extrusion.


  • The two causes of extrusion are:
  1. Reduction in joint space from loss of cartilage.
  2. Tear of the posterior horn root.

Edge > 2.5 - 3.0 mm from Medial Tibial Plateau Margin).

Knee meniscus maceration extrusion injury tear degeneration radiology


  • Maceration of the meniscus is the most severe form of meniscal degeneration. What to look for? Technical term alert…Looks like mush 😀


  • Think of grinding up something in a mortar and pestle and that’s what you get in maceration.


  • The meniscus generally retains it's shape but is ill defined and intermediate in signal.


  • Due to the degeneration it's more likely to tear and it also stops functioning like a normal meniscus.

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#radedasia #mri #mskmri #radiology

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