1 year, 2 days post-op. Last Friday I finished an 8-day backpacking/non-technical mountaineering/high lake fishing trip, half on-trail, half off-trail, some snow (including ascending a high pass in a hail storm), some scrambly (loose class 3 max). New knee felt quite good. I-T band irritation (new knee geometry?), a problem a couple months ago, is better and was not an issue on the trip.
In June, I hit my first 100-day ski season ever! 35 lift-served + 25 XC + 40 ski touring (light AT gear).
All in all, my new knee function is better one year post-op than I had ever anticipated. Knee is solid, strong and stable, although I'd like another 10-20 degrees of flexion. Lack of flexion forces me to do some high steps and higher step kicks on steeper terrain with my natural (i.e., non-TKR) knee. Bicycling the first couple miles can be stiff and a bit painful, but it seems to be gradually improving. Getting out of the tent in the morning is sometimes a hassle. But I'm not complaining. It's great getting back in the mountains! The new knee has allowed me to resume daily aerobic workouts and get more fit than I have been in 6+ years.
I look forward to at least two more week-long mountain trips this summer: Early August for my wife's birthday and early September for my birthday. And I'll likely do some overnights and 3- and 4-day weekends.
Good luck to our fellow post-op comrades!