I've done 2 scopes on each knee and a lateral release on both knees. I turn 48 in a month. It's been about a year and a half since the last scopes/lateral release on both knees and I'm doing okay right now, but knowing my history, I'll be ready for something in another 2-ish years and the doc said that it'll probably be total replacements. I'm good with a TKR on both sides - don't care if they only last 20 years or so.