A meniscal tear can be seen when either the normal shape of the meniscus is disrupted by an abnormal signal, or if a portion of the meniscus is missing.
Meniscal high signal not disrupting the articular surface are caused by intrasubstance degeneration as a result of wear and tear due to age
Tear of the medial meniscus. Sagittal MRI through the medial part of the knee joint showing a tear in the posterior horn of the medial meniscus. The anterior horn appears normal.