HI Joe and others. Each TKR is different, even when done by the same surgeon. Even when done robotic assisted or or not. How much arthritis did a person have? How much were their legs bowed because of the arthritis? How far did the surgeon go to straighten the leg out during surgery? Did your foot or ankle supinate or pronate before surgery? What are your feet doing now. Besides the low hemoglobin, all of these items affected me and rehab pain and getting back into my pace and continuation of mild to moderate pain in the knee that was in the worst pre-op condition. All of these affected my gait. In my case one leg is shorter than the other 1/2 inch. Some therapists will say that 1/2 inch is not significant. It was with me After a put a 1/2 heel lift in my right shoe my gait changed and my balance exercises became easier to do successfully. Which by the way, anyone with TKR especially if both are done, need to do balance exercises. Most people I have met after TKR can't stand on one leg for thirty seconds. Forget about doing it and closing their eyes. Joe where is your pain. The bio-mechanics from your waste down to your toes can all affect knee pain, especially after TKR. Is it mostly on the anterior side just above, at, or just below the knee at the top of the tibia? If any of the pain areas I mentioned are where your pain is at, talk to your therapist about your IT band and the Tensor Fascia Latae muscle which has an unbelievably complex anatomical relationship with the IT band and the stability of your knee. It plays an important part on your posture and one legged stance, which basically happens at every step we take. Think about it. The full weight of your body is on one leg or the other withe each step we take. The TFL muscle plays a super important role stabilizing all of that, even though it is at the upper end of your femur. Often times this muscle is in an over tensioned condition due to our not being in shape, over use or change of gait to to injury or surgery. The tense or weak TFL will cause the IT band to be in tension and that will cause mild to sever pain along the anterior side of your knee. Your therapist hopefully can explain more about the relationship, and show you one of the simple yoga exercises to stretch or loosen the tension of the TFL muscle
It is often called "the standing TFL stretch". I am not a therapist, but have gained an enormous amount of knowledge from the therapists and Doctors I have relationships with. It is simple to do and I have seen it work with eight individuals that I work out with that have had persistent IT band pain. The following technique may sound silly, but I have found that if I walk forward on my tippy toes in my athletic shoes for about 30 to 40 feet and then walk backward the same distance for about three reps, much of the mild to medium pain in my left knee is reduced. I hope some of this info helps you as well others. As Always, Stay Strong-Stay Safe!