Two months ago, an elderly female patient was unable to move her right knee due to swelling and pain from a sprain. After conservative treatment in a local hospital had failed, she recently came to our hospital for treatment. After careful study of her condition, she was diagnosed with 1. right knee meniscal injury and 2. right knee synovitis. After careful study of her condition by the general physicians of the Department of Orthopaedic Surgery, she decided to use knee arthroscopy to perform a minimally invasive subluxation meniscectomy. Indications for arthroscopic surgery: It is useful for a large number of joint pathologies, including trauma and other diseases. 1. meniscal injury, 2. congenital meniscal deformity (such as discoid meniscus), 3. intra-articular free body, 4. cruciate ligament injury, 5. early osteoarthritis, 6. rheumatoid arthritis, 7. synovial crease syndrome, etc. Arthroscopic surgery has the following advantages over traditional incisional surgery 1. 2. Smaller incision, less trauma, 3. Less inflammatory reaction and pain, 4. Less comorbidity, 5. Less postoperative sequelae, 6. No secondary effects, 7.