Hi northlake. I can't stress enough that I agree with Erin that you should contact your doctor as soon as possible if you have concerns about a joint replacement. My wife, Kelly Mack (a contributor here) had an infection in an artificial joint and the doctors moved quickly (but with care) to take care of it. She has written about the process, however, since you do not yet know the cause of your problem the first step is to work with your medical team to determine what may be occurring and next steps. Wishing you the best, Richard (RheumatoidArthritis.net Team)