Hi I went in for my 1 year anniversary and was curious to know why I still had swelling, especially after standing for long periods. I have been very active since the surgery but no impact sports. Anyway my knee cap is moving off center, so far that the edge is actually lined up with the groove. The OS is having me get a second opinion, but he feels the only way to fix it is to open the knee back up, smooth the knee cap and insert the plastic button. He is hesitant to do this because he is afraid the button is going to wear out, I am only 47. He said out of the 1000's of knees he has done, this is the first time he has seen this. Has anyone else experienced this. I am really bummed that I have to go under whole muscle recovery thing again? Curious to know if anyone else has had this happen?