There are two major types of cartilage in the knee. One form of cartilage covers the surface of the bone that forms part of the joint, this is called hyaline cartilage.
Another type of cartilage found in the knee is fibrocartilage which forms the disc shaped material that lies between the ends of each bone (meniscus). There are two menisci, one on the inside of the knee (medial) and one on the outside of the knee (lateral). The menisci are in a C shaped disc, they serve to cushion and improve the surface area of contact between the relatively curved shaped surface of the femur (end of the thigh bone) and the relatively flat surface of the tibia (top of the shin bone).
Tears of the meniscus are more common following an injury than tears of the cartilage that lines the bone (hyaline). Meniscal tears often can cause symptoms of pain in the knee associated with swelling, occasionally they can be associated with locking of the knee or jamming and can also cause the knee to suddenly give way.
Tears of the hyaline cartilage can occur but are less common. Other soft tissue injuries can occur in following an injury. The patella tendon and quadriceps tendon may have tears to it as can the ligaments which hold the knee cap in place.