The so-called knee wear is mainly caused by repeated stress and friction on the knee joint for a long time, which will cause edema and degeneration of the cartilage inside the knee joint, and even cause cartilage fracture and peeling, and will cause the meniscus inside the knee joint to tear and fracture after repeated compression, which will lead to significant swelling and pain in the knee joint. The pain is especially worse when flexing and extending and when moving down to the ground to bear weight. This condition is common in people who are engaged in heavy physical labor, athletes, and middle-aged and elderly people, and is likely to cause degenerative changes in the knee after the knee wears out, resulting in significant osteophytes around the knee and narrowing of the joint space inside the knee.