Floating meniscus

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Floating meniscus (also known as meniscal avulsion) occurs in acute traumatic settings when the meniscotibial coronary ligaments get disrupted leading to avulsion of the meniscus from the tibial plateau.

Radiographic features

MRI

Displacement of the meniscus for 5 mm or more from the tibial plateau with fluid interposed between the inferior surface of the meniscus and tibial plateau indicates a floating meniscus.

Differential diagnosis 

  • Wrisberg ligament type of discoid meniscus:
    • has an anterior tibial attachment
    • lack of history of trauma differentiates from floating meniscus