Your menisci are C-shaped cartilage discs that exist between the two main bones of your knee, at the end of your thigh bone and the top of your shin bone. There are two menisci. One is on the inner side of your knee, and the other is on the outer part of your knee.
Together, the menisci serve to take impacts and stabilize the joint. This protection helps minimize wear of the cartilage that lines the ends of your knee bones. The menisci also help fill other roles that assist in normal knee function and health. Wear or traumatic injuries to the knee can cause damage to this cartilage, which is known as a meniscal tear.