What Is a Meniscus?

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