The knee is the largest and most complicated joint in the human body.The knee joint joins the thigh with the leg and consists of two articulations one between the femur and tibia, and one between the femur and patella.The Knee consists of 4 bones and an extensive network of ligaments and muscles. The knee is a mobile a pivotal hinge joint which permits flexion and extension as well as a slight medial and lateral rotation. Since in humans the knee supports nearly the whole weight of the body, it is the joint most vulnerable both to acute injury and the development of osteoarthritis.
The knee is made up of four main bones- the femur (thigh bone), the tibia (shin bone), fibula (outer shin bone) and patella (kneecap). The main movements of the knee joint occur between the femur, patella and tibia. Just below and next to the tibia is the fibula, which runs parallel to the tibia. The patella, or what we call the knee cap, rides on the knee joint as the knee bends.
The joint capsule is a thick ligamentous structure that surrounds the entire knee. Inside this capsule is a specialized membrane known as the synovial membrane which provides nourishment to all the surrounding structures
Although the knee joint may look like a simple joint, it is one of the most complex. Moreover, the knee is most likely to be injured than any other joint in the body. Injuries to the knee joint are amongst the most common in sporting activities. We tend to ignore our knees until something happens to them that causes pain.
The human knee is associated with the following ligaments:
Menisci of KneeThe meniscus is a C-shaped piece of tissue which fits into the joint between the tibia and the femur. It helps to protect the joint and allows the bones to slide freely on each other.
The articular disks of the knee-joint are called menisci because they only partly divide the joint space. These two disks, the medial meniscus and the lateral meniscus, consist of connective tissue with extensive collagen fibers containing cartilage-like cells. Menisci are cartilaginous elements within the knee joint which serve to protect the ends of the bones from rubbing on each other and to effectively deepen the tibial sockets into which the femur attaches. Either or both menisci may be cracked, or torn, when the knee is forcefully rotated and/or bent.
Movements of Knee
The knee permits the following movements flexion, extension, locking, unlocking, and slight rotation. The ligaments and menisci, along with the muscles which traverse the joint, prevent movement beyond the knee's intended range of motion.