Severe cartilage wear is felt as pain, limited movement of the interlocking joints and joint swelling. The more severe the wear, the more pronounced the pain. 1. Pain: Cartilage covers the surface of the joint, there are no nerves in the cartilage, while there are nerve receptors in the subchondral bone tissue. After severe wear and tear of cartilage, it will expose the bone tissue underneath it, and the bone tissue to friction and extrusion will cause pain, the more severe the wear and tear of cartilage, the more serious the pain symptoms. 2. Interlocking and limited joint movement: cartilage fragments will be produced after cartilage wear, and the fragments will become joint free body when they remain in the joint cavity, and the free body will be stuck between the joints when the joints are moving, which will lead to interlocking phenomenon. Interlocking and joint pain will result in limited joint movement. It affects the movement of the joints. 3. Joint swelling: after the cartilage is severely worn, synovitis will occur due to pulling and irritation of the synovium, resulting in joint effusion. This leads to joint swelling. For severe cartilage wear and tear, joint replacement surgery is needed to provide relief. If the cartilage is severely worn and painful symptoms occur, it is recommended that the patient go to the hospital for a complete examination and targeted treatment.