Articular cartilage is a firm, flexible connective tissue that covers the ends of bones in the knee joint. This tissue acts as a shock absorber and reduces friction in the joint. Sometimes, the cartilage area may become damaged, limiting the knee's normal movement and often resulting into severe pain. The cartilage of the knee is easily injured if the knee is twisted while bearing weight. The seriousness of the knee cartilage injury depends on the location and size of the tear. Various symptoms associated with knee cartilage damage are severe pain, swelling, locking of the knees, and weakening of the knees. Damage to the articulate cartilage of the knee is diagnosed with the help of X-rays, crunching of the joint (crepitus) or locking. There are various treatments available for knee cartilage damage such as exercises to strengthen muscles, electrical simulation, and surgery for severe knee injuries.