Arthroscopy is a rod-shaped optical instrument with a diameter of about 5 mm that is used to view the internal structure of a joint. This instrument has been used since 1970. The arthroscope is equipped with a lens at the end of a thin tube, which is inserted into the joint, and the internal structure of the joint is displayed on a monitor. As a result, the structures inside the joint can be directly observed. Arthroscopy is not only used for diagnosis of diseases, but has been widely used for treatment of joint diseases. Arthroscopic surgery is a minimally invasive procedure that was first used on the knee joint, and later on the hip, shoulder, ankle, elbow and small joints such as the fingers. Arthroscopy can see almost all parts of the joint, which is more comprehensive than cutting open the joint, and because the image is magnified, it is more accurate, and the incision is small, less traumatic, less scarring, faster recovery, and fewer complications. Arthroscopic surgery often has an immediate effect on the diagnosis of difficult joint conditions and on the treatment of joint injuries that have plagued patients for years. Understanding arthroscopy: Arthroscopic technology originated in Japan in the early 20th century and has developed significantly in the United States and other countries since the 1970s. Over the past few decades, arthroscopy has revolutionized the diagnosis and treatment of intra-articular disease. Arthroscopy allows for a comprehensive view of intra-articular structures that is more subtle than incisional surgery, and many intra-articular structures and lesions can be directly visualized and treated. Some have called arthroscopic techniques, along with internal fracture fixation and artificial joint replacement, the three most important advances in the field of orthopedics in the 20th century. Arthroscopy has become so widely accepted that it has become the standard diagnostic and treatment technique, having been called a “young man’s toy” in the past. Arthroscopic techniques are an important part of joint surgery and fully reflect the trend of minimally invasive modern surgery. The basic structure of the arthroscope is an optical system with a central rod system for image acquisition, surrounded by optical fibers for introducing the light source, and a protective metal sheath outside. The arthroscope is inserted into the joint by creating a tiny incision in the skin of about 0.8 mm to 1.0 cm, and a camera and display device is connected behind it, allowing direct observation of intra-articular morphology and lesions, and treatment of intra-articular diseases by using special instruments, thus avoiding many joint incisions. The advantages of arthroscopic surgery: 1. small incision, aesthetically pleasing, can avoid late irritation caused by scarring of the joint surface and sports areas; 2. minimally invasive surgery, less painful, less postoperative reactions, easy to accept by patients; 3. early postoperative movement and use of limbs, avoiding long-term bedside complications, reducing nursing staff and costs; 4. relatively few complications; 5. basically does not affect the peri-articular The muscle structure around the joint is basically not affected, and functional exercises can be carried out early after surgery to prevent disuse and complications caused by long-term fixation of the joint; 6.The observation and examination of intra-articular lesions can be carried out in a near physiological environment, which is known as “putting eyes and fingers into the joint”, and the dynamic examination of the joint can be carried out to improve the diagnostic ability. Some diseases, such as synovial fold syndrome, are established only through arthroscopy; 7. Arthroscopy can perform surgeries that were difficult to be completed by open surgery, such as partial meniscectomy.