Generally, doctors say you should consider surgery when the quality of life is affected so that you can't do what you want or need to do. I put off my first knee surgery for several years after I was told it was an option. Going down steps or on uneven ground was painful, but I made do with cortisone and Synvisc injections a few times a year. My decision to do surgery was made suddenly, when one day going down a grassy hill, my right knee collapsed with no warning in a wall of pain and I tumbled head first down the hill. The next few days I experienced more pain than I had ever felt in that knee, and I was not willing to go through another episode, or wait for one to happen, so I contacted my ortho's office and said I was ready for the TKR. Surgery went smoothly, I had fast healing and good use of my knee. About two years later, I decided to have my left knee done. It never got as painful as my right knee, but I knew it was a matter of time, and thought I might as well get it over with before I got any older. There was a bonus in getting the left knee done, because that leg got a chance to be straightened from a pigeon-toed position that I had developed in an effort to shift the pain, which in turn affected my gait and back, and I no longer have the sciatica on the left leg which I had to deal with in the final year before the left TKR. I am glad I had the TKR's, no daily arthritis pain. I do a lot of gardening, have found I can kneel if I have a thick cushion to support just the lower leg, with the kneecap extending over the edge into air.