The more commonly used drugs for knee joint protection include glucosamine sulfate capsules, glucosamine hydrochloride capsules, and sodium glassate injection. Among them, glucosamine sulfate capsule and glucosamine hydrochloride capsule, the main mechanism of action is to promote cartilage synthesis, inhibit cartilage inflammatory reaction, reduce cartilage surface damage, and have a very significant effect on the protection of the cartilage surface of the knee joint. Although sodium vitrate injection is also a protective agent for articular cartilage, its mechanism of action is not exactly the same as the first two. Sodium vitrate injection can be injected directly into the joint to nourish and lubricate the articular cartilage, joint surface and meniscus.