Two types of cartilage exist in the knee, articular cartilage and meniscus cartilage. Both types of cartilage provide protection to the surrounding joint and bone structures of the knee. The various types of knee cartilage injury to either articular or meniscus cartilage include tears and degeneration over time.
Articular cartilage, also referred to as hyaline cartilage, covers the end of the bones that form the knee joint, including the femur, patella, and tibia. Typically, knee cartilage injury to the articular cartilage is a result of wear and tear of the cartilage over time. Osteochondritis dessicans (OCD) can also lead to articular knee cartilage injury. OCD is the result of a piece of bone or cartilage breaking off from the end of the bone. Sudden twisting can also lead to articular cartilage tear and damage.
Treatment of articular cartilage injuries is based on the extent of damage. An arthroscopy, magnetic resonance imaging (MRI) exam, or x-ray can help diagnose the extent of the injury. For relatively mild injuries, rest may be ordered. Severe injuries, especially those in conjunction with bone damage, may require surgery.
Meniscus cartilage injuries are among the most prevalent types of knee cartilage injury. These injuries are often seen in conjunction with other structural damage. This can include damage to surrounding ligaments, such as the anterior cruciate ligament (ACL).
Several different causes exist for meniscus related knee cartilage injury. Injury can occur from sudden twisting or shearing movements of the knee, as often seen in athletes during sporting events. As people age, something as simple as getting up out of a chair in an awkward manner can tear a meniscus that has experienced degeneration with age.
When someone experiences a meniscal tear, they may exhibit a wide range of symptoms. They may feel pain or a popping sensation right away. Over the course of the next few days, swelling and stiffness may develop. Reduction in the normal range of motion of the knee joint is also a sign of meniscal cartilage injury. Meniscal tears are categorized depending on the location and direction of the tear, and include longitudinal, flap, bucket handle, parrot-beak, transverse, and torn horn tears.
Treatment will depend on the severity and location of a meniscal tear. Severe tears may require surgery. Less severe tears that a physician thinks will heal with at-home care will require rest, ice, compression, and elevation. Over-the-counter anti-inflammatory medications can help with the swelling and relieve pain.