I was always active, marathons, triathlons, racket sports, etc. I lost the ACL in my left knee due to a college football injury. I kept up the activity even without that ACL which resulted in re-injuring that knee multiple times. I had ACL replacement surgery, meniscus repair surgery, excess fluid drainings and kept up the activity. Finally, the pain pushed me to go to a sports orthopedic surgeon who told me bluntly to stop all the sports stuff! He told me the last thing I should do is a knee replacement, spend the time you would be running to do strength exercises for both legs. He sent me to physical therapy to do that. That was 15 years ago and now I just walk. He told me that if after physical therapy day to day activities did not result in pain, then avoid knee replacement. At the time, even my walks (a few miles) resulted in pain, but after the physical therapy and continued strength training that pain has been gone for years. I still tweak that knee occasionally, but it heals after a few days. I can squat, climb a ladder, lift, slide under the trailer and drive long distances pain free.
Hope this helps, just another variable in your decision equation! Mike