I. What is arthroscopy? Arthroscopy is the insertion of a metal tube with an illuminated lens into the joint cavity through a small incision hole to magnify the image on a monitor inside the joint and observe the lesion inside the joint, so it is more accurate than naked eye observation after joint incision. This is a new and advanced technology. Many people think that arthroscopy can be done by taking a picture, but in fact it is a minimally invasive surgery. What are the features of arthroscopy? Arthroscopy is more comprehensive than cutting open a joint because almost all parts of the joint can be seen; it is more accurate than cutting open a joint because the image is magnified; it is less traumatic because of the small incision, less scarring, faster recovery, and fewer complications. The diagnosis of difficult joint diseases and injuries that have plagued patients for many years can often have an immediate effect. In a nutshell, it is a simultaneous examination and surgery, examination and treatment. Which injuries are suitable for arthroscopic surgery? Most knee injuries are suitable for arthroscopic surgery, such as unexplained joint swelling, synovitis, mild to moderate traumatic osteoarthritis or senile degenerative osteoarthritis, intra-articular free body, meniscal injury, cruciate ligament injury, acute joint sprain, patellar subluxation, etc. Intra-articular infections can also be flushed through arthroscopy. Fourth, can arthroscopy completely replace arthrocentesis? The answer is no, because there are still some injuries that can only be solved by arthrocentesis, such as very serious osteoarthrosis, which requires total knee replacement, severe knee tuberculosis, which requires arthrocentesis and fusion, and synovial hypertrophy, which requires arthrocentesis. On the other hand, injuries that are amenable to arthroscopic surgery may still require arthroscopic surgery or a combination of arthroscopic and arthroscopic surgery for various reasons to completely resolve the problem, so when your doctor tells you that arthroscopic surgery is possible, he or she cannot completely rule out the possibility of arthroscopic surgery.