The knee is the largest joint in the body. Each bone end is covered with a layer of cartilage that cushions, absorbs shock and protects while allowing movement.
Cartilage contains no nerve endings or blood supply.
If damaged, the cartilage is not capable of repairing itself. Pads of connective tissue called menisci separates the bones of the knee. They are divided into two crescent-shaped discs located between the tibia and femur on the outer and inner sides of each knee. They act as shock absorbers, cushioning the lower part of the leg from the weight of the rest of the body. Surrounding the knee structure is the synovial lining, which produces a moisturizing lubricant for the cartilage.