I had my left ACL replaced back in 1998, then partially re-tore it in 2002. After three surgeries total on that knee, the Doc told me I’d have severe arthritis and possibly need a knee replacement one day.
Well, fast forward nearly two decades and not only did I have no cartilage at all left in that knee, but the long term limping and other changes in gait, and over-using my “good” knee for so many years, had destroyed all the cartilage in that one also.
Not long after we were shut down from Covid, I got to the point I could barely even walk across the room (use or lose it, and BJJ was the only thing keeping me functional!)
So, after a LOT of research and hard-fought acceptance that I no longer had much choice, and at age 51, I finally had my left knee replaced in February, and my right knee replaced in March.
The right one got infected and so I had to have another surgery for that in April.
At this point, just over 3 months post-op on the left knee I am beginning to be able to kneel on a regular hard floor again, so I am confident I’ll be just fine kneeling on mats once I’m all healed up. I may consider a knee pad with a gel front if necessary, but like you I put the surgeries off a long long time for fear of not being able to kneel again.
Everyone is different, but I’ve talked (online) with a couple other BJJ guys who had knee replacements (one of them had both done) and they are back to training and rolling also. They are kneeling just fine by the sounds.
At this point I’m very very motivated to get back on the mats and - after 20 years of almost continuously training BJJ - FINALLY getting my black belt. I spent 13 years at purple belt due to “life” (long long story) and then received my brown in 2018.
I’m rehabbing seriously, and won’t settle for anything less than a full recovery on the mats. With the way things are currently going, I think I’ll be back in the mats and better than ever before the end of the year.
My advice: Get it done. I wish now I had done it two years ago when the arthritis really started getting bad.