Ozone injection in the knee is the use of special equipment to inject ozone into the knee joint cavity, which has a therapeutic effect on a variety of diseases of the knee joint, especially for degenerative osteoarthritis, acute or chronic synovitis resulting in joint effusion, including choroidal nodular synovitis, and trauma to the knee joint. The principle is that ozone, as a strong oxidizing agent, has certain analgesic and anti-physical inflammatory effects. Therefore, for the physical inflammation produced above, ozone injection can achieve the purpose of anti-inflammation and pain relief, and at the same time can improve local edema and remove free radicals from the injury site. Therefore, the effect is ideal for sterile inflammation caused by chronic strain injury. Generally speaking, ozone injection is not too harmful, but it must be operated with strict asepsis to avoid infection of the knee joint.