Meniscus

Extended Definition

The meniscus is a special type of cartilage found only in the knee joint. Unlike the smooth articular cartilage that covers bone surfaces, meniscal cartilage is tougher and more fibrous. Each knee contains two menisci: the medial meniscus on the inside of the knee and the lateral meniscus on the outside.

These crescent-shaped structures serve multiple important functions. They act as shock absorbers, distributing body weight evenly across the knee joint during activities like walking, running, and jumping. They also help stabilize the knee, improve the fit between the rounded femur (thighbone) and the flatter tibia (shinbone), and assist in lubricating the joint by helping spread synovial fluid across cartilage surfaces.

Meniscus tears are common injuries, especially as people age. The meniscus can tear due to sudden twisting movements or gradually degenerate over time. Damaged menisci don’t heal well on their own because only the outer edges have blood supply. Importantly, meniscus tears and damage are strongly associated with the development of knee osteoarthritis—research shows that people with meniscus tears are at significantly higher risk of developing arthritis in that knee later on. Treatment options range from conservative management with physical therapy to arthroscopic surgery to repair or partially remove damaged meniscal tissue.