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 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 O-shaped (though still essentially C-shaped) morphology. 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 knee pain or audible joint clicking (crepitus) at an early age.

The meniscus is one of the key structural components of the knee joint. Anatomically, it lies between the femoral condyles and the tibial plateau, functioning like a shock absorber: it protects the articular surfaces of these bones and dissipates compressive forces transmitted downward through the joint. Colloquially, the meniscus can be thought of 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—much like water eroding stone over time—leaving it increasingly damaged. Ultimately, during a specific movement of the knee, the meniscus may sustain excessive compressive force and, unable to withstand the load, tear or rupture.