We often speak about the meniscal click and how that can indicate that it is being damaged. In this video Dr Sylvestre demonstrates, using a bone model and then a canine cadaver, how the meniscus becomes damaged.
The medial meniscus is firmly attached to the tibial plateau, therefore during the tibial thrust or drawer motion that occurs in a dog with a torn cranial cruciate ligament (CrCL) the medial femoral condyle rubs over the caudal aspect of the medial meniscus, damaging it. That caudal meniscal pole will then flip forward where it can become further damaged by the medial femoral condyle, especially during weight bearing.
The lateral meniscus has the good fortune of being attached caudally to the femoral condyle. Therefore, during the thrust or drawer motion, it moves with the condyle rather than being static and damaged by the condyle.
Watch this video to the end where you will actually see the medial meniscus pop back and forth under the movement of the femoral condyle.