In reply to David Kirsfelds:
I had the same knee op/ issues.
Took me 6 months to get back into it. Full trust in the knee took me longer.
I have equalled my best grades since the op. But have slightly less flexibility then I used to.
Walking down hill with a pack Sucks.
Uphill isn't such a problem.
Sea cliffs are still great. Flat walk ins and easy abs to the bottom suit.
I gave up bouldering basically as the harness and rope can take the impact and make my knees last longer.
A friend of mine has had both knees done and does iron man regularly. What he'll be like in ten years us anyone's guess.
Good luck. K.