Master Wang had a knee replacement more than a decade ago, and the results were immediate after the surgery, with all the previous leg pain disappearing. However, in recent times, he has been experiencing pain again. He said that the pain was similar to the pain he had before the surgery more than ten years ago, that is, he felt pain when he moved around and was fine after resting. So, what exactly is the reason for the pain that disappeared and came back? Mr. Wang was very worried about this. In fact, there are many reasons for pain after knee replacement, and loosening of the joint prosthesis is one of them. There are many reasons for loosening of the joint prosthesis, mainly related to the surgical technique, the material used to install the prosthesis, and the amount of activity and activity of the patient after surgery. When the joint prosthesis loosens, it starts with a slight movement, which is not very obvious, but this slight movement can stimulate the local peripheral nerves and cause pain when the patient moves. When the loosening becomes obvious, the joint prosthesis is unstable, and this may then result in inversion deformity or ectropion deformity. Simply put, if Wang’s joint prosthesis is severely loosened, it will appear “flashing” phenomenon, that is, when walking to the side skew. So, what should be done at this point? Can we not have surgery? I’ve already been through one surgery, and I don’t want to go through another. Unfortunately, however, surgery is the best solution for patients who have clearly developed a loose joint prosthesis. After all, if the joint prosthesis is loose, just as the original joint is worn out and unusable, the loose prosthesis cannot continue to carry out its “mission”. Even if the patient does not do physical work, this prosthetic loosening will not recover, but will only get heavier. Therefore, joint prosthesis loosening must be treated surgically. As to whether the patient can be operated, the doctor needs to assess the patient’s age, physical condition and other circumstances.