The menisci sit between the tibia (lower leg bone) and the femur (thigh bone) and protect the lower part of the leg from the shock created by our body weight. The medial meniscus sits on the inside of the knee and the lateral meniscus sits on the outside of the knee.
Meniscus tears usually take place when an athlete twists or turns their upper leg while their foot is planted and their knee is bent.
Occasionally menisci can develop as a block or disk shape, which is called a discoid meniscus. A discoid meniscus is more likely to tear and commonly presents in childhood.