Arthroscopic surgery has the following advantages compared to arthrocentesis: 1. Small incision without infection and minimal skin scarring. 2. The surgery is less traumatic, safe, repeatable, and does not affect the joint to do other surgeries later. 3, a single arthroscopy can treat a variety of diseases at the same time, such as knee surgery can be performed at the same time joint cleaning, synovial wall resection, etc. 4, wide indications, it is applicable to a variety of lesions in the joint. There are few contraindications, such as poor physical condition that cannot perform conventional surgery, but not necessarily contraindicated arthroscopic surgery. Arthroscopic surgery can treat various inflammatory diseases in the joints. Such as osteoarthritis synovitis, traumatic arthritis, rheumatoid arthritis, tuberculosis arthritis, septic arthritis, exfoliative osteochondritis, etc., as well as synovial chondromatosis; patellar chondromalacia; bone redundancy (bone spur), free body, synovial wall, joint disorders, meniscal damage, joint capsule adhesions, various intra-articular fractures, various joint adhesions and joint movement restrictions, and various unexplained joint pain.