Degenerative osteoarthropathy (or osteoarthritis), when considered now, should be too general a diagnosis. Like a fracture, it is clinically useful to classify it in a way that facilitates treatment and prognosis, but it does the opposite. Since the advent of arthroscopic technology, many of our interpretations of knee pain as being due to “osteoarthritis” need to be reconsidered. If there is a free body in the joint, especially if there is a large amount of free body, the patient will feel as if there is something wandering in the joint. For this type of osteoarthritis, the application of arthroscopic techniques to remove the free body can provide longer-term pain relief or greatly reduce the frequency and degree of swelling and pain. 2, synovitis lesions This disease also has a variety of causes, mostly recurrent knee swelling, pain. Often the diagnosis is not clear and it is generalized to arthritis. Arthroscopic removal of inflamed synovium under direct vision is a great superiority and progress over previous open surgery: less traumatic, more complete resection, faster recovery, lower cost, and can be repeated if necessary, but the results are better in early stage. 3, chondromalacia patella It mostly appears after sitting in one position for a long time with obvious pain symptoms, sometimes obvious when going up and down stairs, but no symptoms when walking on a flat road. There are various causes of chondromalacia, and the following methods are available depending on the cause: A. Release of the lateral support band. B. Tibial tuberosity advancement surgery. C. Local excision of the defect combined with drilling of the subchondral bone in advanced and severe cases. For patients with narrowing of the joint space on x-ray and recurrent pain in the knee, many physicians advocate joint replacement, but many are reluctant to accept the greater surgical risks and costs, but for “unicompartmental lesions” a very old surgical approach is available for long-term pain relief ——- “Osteotomy orthopedics”. Because many people with this type of “unicompartmental lesion” complain of pain mainly on the medial side of the knee, but relatively little pain on the other side, and the appearance of an “O” leg, force line changes are fundamental, so this very old procedure can be used here to solve a major problem. The correction of the force line combined with arthroscopic intra-articular cleaning can relieve the pain of this lesion for a longer period of time. 5. Synovial crease syndrome The crease in the knee joint is an embryonic remnant, and some people can have knee pain due to its pathological changes. However, it is mostly seen in young people, around 20-30 years old. That is why it has also been diagnosed as osteoarthrosis. It can develop with a history of trauma and in most cases pain on the anteroinferior aspect of the knee after repetitive motion, or a popping, or bulging sensation. It can be treated with arthroscopic resection. Of course, there are many other factors, but finding the painful target and addressing it will relieve the pain, which is the purpose of my appeal.