Discoid Meniscus

The meniscus is a cartilage structure in the knee that sits on top of the leg bone (tibia). Each knee has two menisci, an inner and an outer meniscus. The meniscus functions like an adapter between the rounded thigh bone (femur) and flat tibia. It also helps distribute the forces between the two bones over a greater area (rather than point to point), helps supply nutrition to the cartilage that lines the bones (articular cartilage), and helps stabilize the knee. A discoid meniscus is a congenital (born with) variant of the normal meniscus. Instead of being shaped like a cashew nut, the meniscus is more oval or disk shaped. Occasionally, it has a normal shape with abnormal attachment to the surrounding structures. It tends to occur in the outer (lateral) meniscus. The meniscus may cause symptoms without injury or can cause symptoms when torn or injured.