Your surgeon has probably explained the pros and cons of either waiting or taking action now. If you have not had this discussion, it would be a good idea to contact him or her by phone to review your options.
There is no clear way to know what is best. Each patient must be considered individually. Studies have not been done to show the optimal time for revision surgery once there are signs of bone changes or implant loosening.
In general, some surgeons advise a wait-and-see approach when patients do not have painful symptoms and the process is slowly progressing. Eventually the problem will probably get worse and revision surgery will be required. In such cases, the patient should stay in close contact with the surgeon to determine the best time for the operation.
On the other hand, surgery is recommended right away for patients who do have painful symptoms and/or when the X-ray shows rapid bone changes. Any time bone support is eroding, instability can occur making matters even worse. Removing and replacing the failed implant can help restore function and prevent further joint damage.