Human body has three sorts of joints viz. fixed joints, cartilaginous joints and synovial joints, to facilitate various limb movements. Knee joint, the one of the most significant joints in human body, is a synovial joint. This Knee Joint assists to carry the body weight during the movementslike, walking, sitting, bending of legs, driving and various other activities performed by a human. Humans mostly make use of knee while having mobility orwhen they need support to stand and sit.
The structure of knee joint has, majorly three bones. They are Femur or the Thigh Bone, Tibia or the prime bone of lower leg and Patella, what is known as Knee-Cap. These all bones are having a cover of cartilage at their ends. Thus a joint is formed, which has a fluid, known as Synovial fluid to lubricate the movements of joint. This lubricant, synovial fluid is held inside the synovial membrane, generally known as joint capsule
During a total knee replacement, a surgeon removes some bone and cartilage from the areas of your thighbone and shin bone, where they meet at your knee joint. The surgeon then replaces the knee area of your thighbone with a metal implant and the knee area of your shinbone with a plastic implant. This gives both bones of your knee joint smooth surfaces again so they can flex and bend more freely and painlessly. In many cases, the surgeon also replaces the undersurface of your kneecap with a plastic coating.
The main purpose of this cartilage is to provide a movement to the bones, which is smooth, having nofriction among them and is without any effort. The synovial fluid provides synovial membrane such wonderful abilities to maintain these kinds of free movements of knee joints. The cartilage is a much like a layered structure of a tissue, which is flexible and it ensures that the surfaces of bones in the joint, slide smoothly, thereby protecting the bone also. However, this cartilage restores itself, while it wears out, but, in a very limiting way.