Knee strengthening and injury protection

Elliptical and stairmaster everyday, low impact and it works the entire body

Seriously...

get thee to a PT

good luck getting back to full force soon!

Silas - sorry you're having Knee Challenges.
glad you're seeking solutions - the ones mentioning good PTs to me seem particularly valueable.
And don't overlook recovery time... geezers need lots of recovery time :

Olympic Physical Therapy has an approach called Athletic Engineering. I saw a presentation at REI and was intrigued. The focus was on building core strength, but it might be worthwhile to see what their approach to building and maintaining leg strength is. As well, they have eight locations.

I second the idea of adding bicycling to the training/rehab mix. It is a wonderful activity for an aging body.

The geezer body does not respond well to overuse. There is a higher than zero probability that skiing 8 out of 9 days might fall into that category.

I'll pick up something helpful here as well.
As someone who had two surgeries for meniscus repair I have a few ideas.
First surgery was over 8yrs ago at age 58. Most likely caused by being a bad telemark skier. I had a damn good Surgeon who knew my desire to get back on planks.After meniscus repair and scraping of arthritis I did my own therapy which included stretching weightlifting on machines and mt biking. In 5 months I was back skiing and in a year I was at top strength and slowly switched to AT rig with some telemarking. I retired last October and went ape skiing most every day that was practicable. As a result my knee took some serious strain and slowly went cranky until till last April when it final gave out at the top of Mt Batchelor. Again torn meniscus in couple spots. Painful and no control whatsoever. Surgery in May and now after self directed therapy I'm picking up the pace again. According to the Doc I have about 40 to 50 % meniscus left. Self rehab was more difficult this time and took longer. It's still not clear if I'll ever get a 6000' day again at age 66. Ive been moderating my days and am very thankful for how much I can ski. My advice is professional rehab, along with your own enthusiasm and pace yourself. Some glucosomine/chondriton tabs,constant stretching or yoga won't hurt.
Right now I'm good for about 3000' vertical or about 1/2 day lift served and I'm damn glad to get that.
Good luck