I complained to my PA about a month ago about pain under the knee where the stem of the implant goes into the bone radiating to the inside. She said it's all part of the healing process. I don't feel it at all unless I do a whole lot of walking or biking, or carrying something too heavy. For now, I'm avoiding the heavy lifting! If you are concerned about yours, you can always call your doctor. They'll be glad to answer any of your concerns..