I. Arthroscope The full set of arthroscope consists of lens, light source, monitor, surgical instruments under the lens, planing system, etc. During surgery, a 5mm diameter lens is inserted into the joint cavity, and with the help of fiber optic illumination system and computer imaging system, the lesion in the joint is displayed on the monitor after magnification, and the joint is examined and operated under the surveillance of the monitor. If a lesion is found, delicate special instruments are inserted to remove the lesion or perform joint debridement. Because arthroscopy can observe almost all parts of the joint, it is more comprehensive than open surgery; the image is magnified, so it can be observed more clearly, and all the surgical instruments of arthroscopy are small, so the skin incision is small, and no sutures are even needed after surgery. Arthroscopic surgery Arthroscopy is a high-tech minimally invasive technology, which is a major breakthrough in modern medical technology and one of the development directions of joint surgery. Arthroscopic technology is the use of arthroscopy to examine, diagnose and treat joints. The examination of the condition can be carried out under the microscope at the same time, without the need for large incision surgery. At present, arthroscopic surgery is used for shoulder joint, wrist joint, interphalangeal joint, hip joint, knee joint, elbow joint and ankle joint, etc., among which knee joint is the most widely used and mature. Knee arthroscopy Knee arthroscopy is considered to be a better treatment for knee lesions. Traditional knee surgery is very traumatic, bleeding, slow to recover, and has a large surgical scar on the joint. In contrast, knee arthroscopy has the advantages of less trauma, less bleeding, exact efficacy, faster recovery, fewer complications and smaller surgical scars. It is considered the “gold standard” in the diagnosis of knee disorders because of its high diagnostic accuracy and its ability to detect disorders that are difficult to detect on radiographs and MRI. Knee arthroscopy does not require extensive exposure of the joint, so it is less invasive than an incision, less bleeding, less painful, less complications, and allows for early release from bed and a significantly shorter hospital stay. In contrast, conventional knee surgery used to require an incision of about 10 cm. Such a small incision eliminates the fear of scarring for many patients, especially women, and makes them more receptive to surgical treatment. Fourth, the common scope of application of knee arthroscopy 1, the examination and diagnosis and treatment of knee injuries, post-traumatic intra-articular bleeding is an important indication for the selection of arthroscopic examination. (1) meniscal injury; (2) anterior and posterior cruciate ligament injury; (3) osteochondral injury; (2) rheumatoid arthritis; (3) septic arthritis; (4) tuberculous arthritis; (5) pigmented choriocapillaris-like synovitis; (6) degenerative arthritis; (7) synovial crease syndrome; (8) intra-articular free body of the knee; (9) tumor: observation of the extent of intra-articular cavity lesion invasion and intra-articular tumor tissue biopsy. 10. Examination and treatment of unexplained knee pain, swelling and restricted activity. V. Pre-operative preparation for knee arthroscopy Pre-operative knee X-ray or MRI, regular blood biochemical examination, exclusion of acute infectious diseases, serious local or systemic infections are required. After surgery, the knee joint should be wrapped with pressure and elastic bandage, and an ice pack can be used on the knee joint to reduce blood accumulation and swelling of the affected limb and relieve pain. Isometric contraction of the quadriceps muscle of the affected limb can be performed after surgery to effectively prevent the occurrence of postoperative muscle atrophy. Early after knee arthroscopy, active and passive rehabilitation of the knee joint is carried out, and functional training of joint flexion and extension can also be carried out with the help of CPM, with special attention to the training of quadriceps muscle strength, which should be continued after discharge from the hospital and should be maintained until about six months after surgery.