The arthroscope is a very slim endoscope, with a diameter of only 1.9-4.0 mm. Other auxiliary equipment includes light source, optical fiber, video recording and monitoring system, and special surgical instruments. The operation is performed by making a 5mm hole through the skin to insert the arthroscope into the joint, and the detected images are magnified and displayed on a monitor. This allows the surgeon to see the lesions in the patient’s joint more clearly without cutting into the joint. At the same time, the surgeon can use the arthroscopic surgical instruments to remove the diseased tissues for cytopathological examination to make a clear diagnosis; he can also remove the lesions in the joint (e.g. hyperplastic synovium) or repair them (e.g. ruptured meniscus, etc.), and the postoperative function of the joint is almost unaffected, with no surgical scars and a hospital stay of only 7-14 days. It has the advantages of small incision, less trauma, less scarring, faster recovery, less complications and lower cost. Arthroscopic surgical indications: Arthroscopy has a wide scope of application. Arthroscopic examination and treatment of hip, knee, ankle, shoulder, elbow, wrist and other large joint diseases are feasible, mainly as follows 1. Knee diagnostic examination: including examination of knee disorders with unclear clinical diagnosis, biopsy of intra-articular lesions, diagnostic confirmation before open surgery, preoperative evaluation of total knee replacement or high tibial osteotomy for single-chamber osteoarthritis 2. total resection, subtotal resection, partial resection, suturing and disc cartilage shaping for meniscal or disc cartilage injury and degeneration; 3. synovial biopsy and synovectomy for different types of synovitis, including rheumatoid arthritis and other synovial lesions; 4. joint debridement and irrigation and drainage for septic arthritis; 5. focal removal for knee tuberculosis; 6. synovial strangulation 7. removal of hyperplastic fat pad; 8. removal of intra-articular free body or intra-articular foreign body caused by synovial chondromatosis and other causes; 9. joint washout and joint cleaning and cartilage scraping and drilling for osteoarthritis; 10. repositioning and internal fixation of exfoliative osteochondritis or intra-articular fracture; 11. repair or reconstruction surgery after cruciate ligament injury; 12. patella Dislocation and subluxation of the patellofemoral joint caused by the release of the lateral support band and the tightening and suturing of the medial support band; 13.Crystal removal of gout of the knee joint. 14, acute traumatic hematoma, X-ray does not find fracture, clinical examination and no obvious ligament injury can be arthroscopic examination, flushing, clear diagnosis of further treatment.