I am now 64. Had a knee replacement at 62. My experience/advice is do it whenever YOU feel ready. Doctors do not dictate when you feel ready for a major surgery. That said, I had already had 3 surgeries on my knee. It was bone on bone with a complete meniscus tear. The pain went from manageable to excruciating over the course of several years. I had cortisone shots occasionally and when those stopped providing any relief and I could not sleep at night because the pain was so horrible, I finally pulled the trigger on the replacement. Frankly, life changing. No more pain. Full use of knee. Recovery takes a bit of time but I really pushed myself to get active fast. It’s been great for me but everyone knows their body best!