Osteoarthritis of the knee is one of the most common causes that affects people’s ability to exercise and affects their quality of life. Degeneration of the knee joint usually begins in the 40s. According to the degree of degeneration of the knee cartilage, osteoarthritis can be divided into 4 stages. Stage 1 osteoarthritis: The main manifestations are mild pain and swelling of the knee joint, basically normal x-ray performance, and the appearance of articular cartilage. Non-surgical treatment is generally performed in this case, and the results are better. It includes activity reduction, physical therapy and medication, mainly NSAIDs anti-inflammatory and analgesic drugs. Stage 2 osteoarthritis: The main symptoms are pain, swelling and reduced range of motion in the knee joint. x-ray shows narrowing of the joint space, or early degeneration and fibrosis of the joint cartilage. This condition can be treated non-surgically or, if the disease is of long duration or recurrent, arthroscopic clearance can be performed with good results. Stage 3 osteoarthritis: In addition to the symptoms of stage 2 above, there is often a feeling of stuck or locked joints. x-ray shows narrowing of the joint space, formation of bone redundancy, and in some cases, inversion deformity, commonly known as rotundity. Large cracks or peeling of the articular cartilage may occur. Arthroscopic cleaning is usually more effective. Stage 4 osteoarthritis: The main manifestations are rest pain, deformity, and limited movement. x-ray manifestations, in addition to the above phenomena, are mainly complete cartilage wear, bone to bone contact, and ivory bone. This is a manifestation of end-stage osteoarthritis of the knee joint, and only artificial knee replacement can be performed. However, for early osteoarthritis, if there is a combination of patellar subluxation or patellar tilt, or inversion deformity, it is best to correct the problem surgically, which can delay the rapid degeneration of the articular cartilage.