Joint Cartilage Meniscus
The meniscus is a crescent-shaped structure of cartilage that exists in the knee joint and is enclosed on two of its borders by the synovial membrane. The meniscus, is found in the knee joint, as well as the temporomandibular, sternoclavicular, and acromioclavicular joints. The meniscus of the knee has an important role in biomechanics and shock absorption. The meniscus acts as an additional layer of protection for knee joint structures such as the articular cartilage. When you walk, or climb stars, your knees must absorb forces 2-4 times your body weight. Higher impact activities such as landing after jumping running, and climbing may cause your knees to absorb ever higher pressures. The meniscus helps your knee joints to absorb some of these higher pressures, contributes to joint stability, and acts as a cushion between the tibia in the lower leg and the femur in the upper leg. Some people who have injured their meniscus (usually the medial meniscus) due to trauma or accident may require removal of their meniscus in order to stabilize the joint. In other cases of injury, surgeons may be able to repair the joint, depending on the type of tear of the meniscus and the extent of damage. Loss of the meniscus due to injury, degeneration, or surgical removal may cause may make the atricular cartilage more vulnerable to degeneration or injury due to the added weight it must absorb to compensate for its loss. Damage or loss of the meniscus may the articular cartilage more prone or injury or damage, and the joint itself may be more at risk of developing osteoarthritis in the future.
The main components of the knee joint include the lateral and medial meniscus, the lateral and medial condyle of the femur, fibular collateral ligament (which connects the fibula to the femur), Tibial collateral ligament (which connects the tibia to the femur). Other ligaments of the knee involved with movement and stability of the knee joint include posterior cruciate ligament, anterior cruciate ligament ACL, and ligament of Wrisberg. The anatomical parts that are most commonly involved with major knee injuries include the ACL, MCL (Medial Collateral Ligament), and meniscus. Injuries to the ACL and MCL usually involve letting these ligaments heal on their own or grafting new tendons from a different area of the body into in place of their sheared or ruptured tissues. Injuries to the meniscus may involve repair or removal, depending on the severity of the injury or extent of deterioration in a wear and tear condition. The shape and composition of the meniscus are similar to those of the intervertebral discs of the spine.
The two menisci of the knee are designed to withstand the considerable pressures causes by tension and torsion as we move our bodies and concentrate forces towards our lower leg. The menisci have a flat, disc shape, like the discs of the spine. The menisci articulate with the tibia inferiorly, where they have a flat shape, and the femur anteriorly, where they have a slightly concave curvature.
In some cases, the menisci are removed when they are considered beyond repair. One new development in orthopedic medicine is a procedure known as meniscal cartilage replacement therapy.
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