Everyone is different so I hesitate to reply but since I have at least my experience, I will share that... I have always been more or less fit, and a runner. By end of 2016, I also had terrible bone on bone knee pain as you, requiring NSAIDS to survive normal life. The real kicker was when I could not sleep more than about 90 seconds at a time, since the pain would continually wake me through the night. At any rate, running, BASE, skydiving, skiing are my hobbies and I told the surgeon and he went to work. Had the left knee replaced January 2017 with some high flexibility captured contraption. He said it would be 4 months till I'd be active, but I can (for me, anyway) dispel that myth and tell you it was more like just after 2 years. After the first knee replacement, the doctored leg got _significantly_ smaller as it seems muscles were compensating on both legs, leaving my right side very much over-powering my left side, leading to back pain and an odd stance. "Luckily" my rt knee was also shite so in February 2018, that one was replaced. My legs were significantly straighter, and the muscles began to even out on both sides. Pain is high for the first week or two. Can walk immediately, and activity returns quickly, but any impact sports need to wait. By 2019, I was fully active again although my running suffered horribly pace wise. Could do everything else, though I wear swoop pants with integrated knee pads just in case. Rt knee was still sensitive to impacts. By 2020, then 3 years on left and 2 years on right, can kneel to pack and do everything more or less normally. Knees are not as good as organic, and legs not as strong as before, but I would say maybe 90 percent as good and virtually no pain in either leg. I do squats with small weights, under 105 pounds, but all other exercises/activities are pretty much normal. Some weirdness prevails in the form of odd muscle spasms in odd places (calves and upper abdominals) from time to time. Didn't have that before. Nothing debilitating. All in all a very worthwhile experience, I would absolutely do it again. Been jumping again in 2021 and all is good, no issues. Currently a bit over 60yo, gonna join SOS I guess...
