|After having total knee replacement (TKR) surgery on both knees in separate surgeries, I am experiencing severe pain in my left buttox and lower back. Physical therapy hasn't helped much and the prescribed exercises don't seem to help. Sitting for any length of time is miserable. Has anyone who had TKR surgery experienced this problem? Prior to my TKR sugery I had no buttox or back pain The pain is excruciating at times.