Artificial knee replacement is required when the knee joint is too worn to walk and there are significant limitations in daily life. There are two types of replacement: total knee replacement and partial knee replacement, depending on the type of prosthesis. If 2/3 of the knee joint has been destroyed, doctors usually recommend a 3/3 total knee replacement because it is a simple and inexpensive procedure. However, this sacrifices the 1/3 of the joint that is not worn out and removes the anterior and posterior cruciate ligaments, making the post-operative function significantly inferior to that of a normal knee. Zhang Wentao of the Department of Sports Medicine and Rehabilitation at Peking University Shenzhen Hospital is ideal for replacing worn joints, but currently the manufacturer only offers a separate skid joint and unicondylar joint prosthesis, which means that if you want to do a 2/3 knee replacement, you have to do 1/3 + 1/3 separately, and the cost of two sets of joints is not acceptable to everyone, although the function is much better than a total knee replacement. If the wear is only 1/3, a unicondylar or pulley replacement is appropriate because it destroys very little of the normal structure and preserves most of the anatomy of the knee, such as 2/3 of the joint surface, anterior and posterior cruciate ligaments, etc. Also, the patient’s knee sensation is preserved and recovery is quick with minimal trauma. Usually, they can go down to the ground the day after surgery and can do cycling training ten days after surgery. The patient in the picture has been able to do cycling 10 days after the unicondylar knee replacement.