What Is a Meniscus?

The meniscus is, in fact, a fibrocartilaginous structure situated between the bones of the knee joint. The meniscus located on the medial side of the knee is called the medial meniscus and has a C-shaped configuration, whereas the one on the lateral side is termed the lateral meniscus and exhibits a more circular, O-like variant of the C-shape. In some individuals, the meniscus develops abnormally into a disc-like shape from birth—termed a discoid meniscus. This represents a pathological condition, and patients with discoid menisci often experience early-onset knee pain or joint clicking (crepitus).

The meniscus is one of the essential structural components of the knee joint. Anatomically, it lies between the femoral condyles and the tibial plateau, functioning like a shock absorber that protects the articular surfaces of both bones and dissipates compressive forces transmitted downward through the joint. Colloquially speaking, the meniscus acts as a cartilaginous “cushion” within the knee joint, serving to buffer mechanical stress and enhance joint stability. To fulfill its role in minimizing bone-on-bone wear, the meniscus itself undergoes gradual, cumulative wear and tear—akin to water slowly eroding stone over time—leaving it increasingly damaged. Ultimately, during a specific movement of the knee, the meniscus may succumb to excessive compression and tear or rupture.