Menisci:

Semilunar fibro cartilaginous discs

Nearly semicircular and larger. More fixed by attachment to tibial collateral ligament and anterior cruciate.

Lateral:
Nearly circular in shape. more mobile

Functions of the menisci:

1. Increase the congruence of articular surfaces
2. Shock absorbance.
3. Protect the articular cartilage on the femoral and tibial condyles.
4. Distributes synovial fluid
5. Increase proprioceptive sensibility