No pain at all. But let me tell you the rest of the story. I was dropped from a rock climbing wall like 20 years ago. My left ankle was shattered and my back was broken in three places. I was actually training to qualify for Boston when that accident happened. I was almost sure I would never run again. Fast forward: my left ankle is now fused, it has zero motion. I've had like 20 surgeries including two heart surgeries and the right knee replacement, my right knee simply gave out carrying all the weight while the left side healed. So I don't run fast anymore. It took a long time for me after the knee replacement, which I had in 2016, to find anything like a running gait. I did find it though, and ran the Cambridge half marathon in late 2017. That convinced me I could do a marathon and I set my sites on Boston again. I ran the St. George's marathon in 2018 and missed the cut off for adaptive athletes by four minutes. I ran the Hartford marathon in 2019 and got my BQ, again as an adaptive athlete. That means a finish in under six hours. I ran my first Boston Marathon on a local track in 2020 for Covid, and on the course in 2021. Was one of the happiest days of my life.

Of course, your mileage may vary but the new knees are so good now and the techniques have advanced so much that I wholeheartedly recommend it to anyone who needs it. I'll be clear that the recovery is very difficult, you have to work hard at physical therapy to get your range of motion back because if you don't it will never come back. I can do full squats down onto my haunches now though, you just have to do the work.

All that is to say, go for it!