Knee osteoarthritis, also known as degenerative knee arthritis, is a degenerative disease that occurs as a result of the wear and tear or damage to the cartilage in the knee joint over time. This condition breaks down the protective surface of the cartilage, causing the bones to rub against each other. Consequently, pain, stiffness, swelling, and limited range of motion occur in the joint. Normally, the knee cartilage covers the posterior surfaces of the thigh bone (femur), shin bone (tibia), and kneecap (patella), ensuring smooth joint movement. As the cartilage wears down, the space between the bones narrows. As the disease progresses, the cartilage can completely disappear, leading to direct bone-on-bone friction.