Dave,
I'm guessing with you being an avid outdoorsman, you've put your knee replacement to the test. My knee surgeon cautioned me about having a knee replacement at too young of an age. That they can wear out and it's hard to re-replace them. I'm 60 now, so I'm closer to the age he thought would be appropriate to do it. I've had 5 invasive knee surgeries already and don't look forward to many more if I can help it. I'm afraid magnets will start sticking to me.
Are you still satisfied with yours? I think I might want some hydraulics and a zerk fitting installed too.
The doctors told me to go until I just couldn't do it anymore without a replacement knee. So, when I couldn't walk more than a block without my knee swelling up and I had tried cortisone injections and such I said it was time. When they had cracked open my knee back in high school (before arthroscopes) they just took out the torn meniscus on the outside. They took the whole meniscus which they don't do anymore but it was just the lateral portion of the knee that was affected.
When I had the knee replaced, I had worn through the cartilage that covers the end of the bones and had been wearing the bones themselves down to where I was knock-kneed on that side and it was starting to give me hip pain. That was another factor, I didn't want to get to where I had to replace another joint.
I'm not a doctor, but my doctor said that the replacement joint doesn't commonly wear out. One of two things happen.
1) The articulating surfaces wear down. They can be replaced without getting a whole new joint, so every 2-3 years they X-ray that knee to see how its doing.
2) the metal rods that are inserted into the tibia and fibula (the upper and lower leg bones) can come loose. That happened on older models because as the surfaces wore, the particles would drift down and irritate the lower leg bone where it is adhered to the metal and the rod would come loose.
Newer models don't have that issue. For one thing, the surfaces are much, much more durable. I've had mine 8 years and there is no sigfnificant wear and that's with me at the gym on the elliptical or treadmill or sometimes the stair climber and doing classes similar to cross-fit that involve squats, lunges and burpees, etc.
That bone-to-rod adhesion can also come loose from jarring, so when I told my doctor that I was starting to do some running on the treadmill he told me to stop immediately. So, I stick to the aerobic machines and the classes I mentioned, plus I occasionally do stairs or go hiking. When the class is doing jumping jacks or skipping rope I do something different with my feet planted on the ground. Cycling or swimming would also be good if I liked them more.
Hope that story helps. I always tell people to get it done when they really need it and to have a super-specialist at a major medical center do it. I've heard too many stories of people whose joint replacement did not turn out well and it usually turns out that it was not done by somebody well-known in that field that does these things all day.
If I were you, I would lean strongly to having it done in Seattle, San Francisco or Denver. No offense to your doctor but this is one surgery where you need a top-notch doc that does no other kinds of orthopedic surgeries because if it goes wrong, you're up the proverbial creek.