Let’s start with a photo: the many pieces of varying sizes shown in this photo are the “free bodies” we removed from a recurrently swollen knee, and that’s not all of them, some have been flushed out. This is his x-ray: the arrow shows the free bodies that we can see, but the amount obviously does not match what we removed in the picture above, because most of them are not visible on the x-ray. Therefore, it is not always possible to confirm the diagnosis of free bodies in this type of patient by radiographs, and an experienced physician needs to confirm the diagnosis by a detailed history and direct physical examination. This patient’s history was like this: recurrent swelling and pain in the knee joint, which could improve after treatment, but soon recurred. The sage of medicine said, “Seek the root of the disease”, what is the “root”? “The reason why the patient cannot be completely cured is that the free body cannot be removed. Even with the best Chinese medicine and acupuncture, I think Zhang Zhongjing would not be able to handle it if he were alive. How do we treat it? We used arthroscopic technique to remove the free body, and he could walk on the ground the next day without much pain. The first picture shows the free body removed by arthroscopy. The picture below shows the scar of the incision. For this type of patients, or similar lesions, and many knee lesions, including some fractures, such as tibial intercondylar spine avulsion fractures, tibial flat fractures, and some tibial plateau fractures can now be treated with arthroscopic surgery, and the results are much better than the previous incision (which required an incision of tens of centimeters). —— Not only is the size of the incision a problem, but the thoroughness and effectiveness of the surgery are not as good as the previous incision. The results are not only the size of the incision, but also the thoroughness and effectiveness of the surgery, which is unmatched by the previous open surgery, and the rapid recovery, especially the scar is very, very inconspicuous.