Hi Greg,
I suffer from arthritis in both knees. However, I'm not sure I have ever found a shoe with more cushioning that really made a big difference to that. I'm sure someone will be along to contradict me soon!
Personally what I have found, is that switching to more minimal shoes has forced me to run more on my toes and as such causes less pain in the knees. I used to run in Nike Pegasus on the road - now use Saucony Fastwitch. Again rather than aasics trail shoes, I generally now only use Inov-8.
Also regular exercises to strengthen the muscles around the knees and stretches e.g. ITB, calf etc. should help. I'm sure if you have an arthroscopy, you will be prescribed this by physio anyway.
Good luck and keep on running!
Edited: 15/02/2013 at 07:56