What Is It? A meniscus is a disk-shaped piece of cartilage that
acts as a shock absorber inside a joint. Each knee has one
lateral meniscus under the outer knob of the thighbone and one
medial meniscus under the inner knob of the thighbone. Each
meniscus acts as a natural cushion between the thighbone (femur)
and shinbone (tibia). The two cushions prevent excess wear and
tear inside the knee joint by keeping the ends of the two bones
from rubbing together. Each meniscus also absorbs much of the
shock of jumps and landings and helps to distribute joint fluid
evenly to lubricate and nourish the knee. In the United States,
a torn meniscus is the most common reason for knee surgery. The
symptoms of a torn meniscus can include: - Knee pain, usually on
one side of your knee - Tenderness at the side of the joint -
Knee swelling within the first 12 hours after injury - A
"locked" knee that can't be bent - A knee that catches during
movement, or can't be fully straightened - A click, pop or
grinding inside your knee w