Osteoarthritis is a kind of arthritis caused by damage to cartilage and surrounding tissues in a jo...
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Osteoarthritis is a kind of arthritis caused by damage to cartilage and surrounding tissues in a joint. Osteoarthritis can develop in almost any joint, but it most commonly occurs in the knee. Four bones come together at the knee: the shin bone, or tibia; the fibula, which runs alongside the tibia; the thigh bone, or femur; and the patella, or knee cap. The knee joint itself is made up of the patella, tibia and femur. Normally, the ends of the femur and tibia and back of the patella are covered by smooth cartilage. It acts like a cushion between the bones. The cartilage also provides a smooth surface for the interactive movements of the bones. In osteoarthritis, the cushioning cartilage wears down. It can fray, tear, or even wear entirely away. The pressure on the ends of the bones increases, and they may begin to rub against each other. This can cause the ends of the bones to get thin. New growths of bone, called spurs, can form around the joint edges as your body tries to redistribute the weight to the damaged joint. The space between the joint narrows. Small holes can develop in the ends of the bone. Small pieces of cartilage or bone can break off and float around in the tissue capsule surrounding the joint. All of these changes can cause pain and loss of function in the knee joint.