1, diagnostic knee examination procedures: including examination of knee disorders with unclear clinical diagnosis, biopsy of intra-articular lesions, diagnostic confirmation prior to open surgery, and preoperative evaluation of total knee replacement or high tibial osteotomy for unicompartmental osteoarthritis to obtain visual information of the condition. 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. wrinkle resection for synovial strangulation syndrome, 7. hyperplastic hypertrophy of 8. removal of intra-articular free bodies or intra-articular foreign bodies caused by synovial chondromatosis and other causes; 9. joint irrigation and joint cleaning for osteoarthritis and cartilage repair and drilling; 10. repositioning and internal fixation for exfoliative osteochondritis or intra-articular fractures; 11. repair or reconstruction surgery after anterior cruciate ligament and posterior cruciate ligament injury; 12. joint repair for patellofemoral dislocation or subluxation caused by Arthroscopic tightening and suturing of the medial support band and release of the lateral support band for patellofemoral joint lesions.