Hey Bill,
Welcome aboard. You've come to right place to get kokanee advice of all sorts.
You are lucky to have ample time following knee replacement for recovery and PT before the season begins. I wish you well. I had both knees replaced a few years back, one after school was out in December and the other at spring break, mid March. I was fishing in early May and the only knee concern was ice on the back deck from splashed water. I felt like a pig on ice skates. If you have carpet you'll face less risk, or wait for warmer weather. Working the PT consistently paid off handsomely for me.
I had a hip replaced last November and I'd go fishing today if the lake and the boat weren't frozen in. I also seem to have more mechanical moving parts than my boat, so my judgement is hardly sound.
Here is one thought about kokanee fishing: Kokes are the best fighters I know, pound for pound, and they are also the best eating. It seems to me some people optimize their gear to catch more kokes for eating (and may use heavier gear in order to lose fewer fish). Others optimize for the fight, using very light gear and probably losing more fish. It certainly isn't a perfect trade off, but I see plenty of boats equipped with very heavy gear and boats with very light gear, and not very many with both types. Or perhaps people just fish for kokes with the equipment they already have on board for other species. Try both heavy and light if you can, there is a world of difference.
Best of Luck, Roger