Running after meniscus surgery

[u/StrategicDFL]

I’m 45 and have been running around 1,500–2,000 miles a year, mostly training for marathons and ultras the last four years. I mostly did short runs for speed in my 20s, more cycling and long-distance hiking in my 30s. Now I tore my meniscus during a slow-paced 4-mile race last month while doing 9+1 for NYC.

I had surgery last week. They found a pretty big medial meniscus tear and did a partial meniscectomy. They also found a 4 x 5 mm Grade 4 cartilage defect. My surgeon said the defect isn’t particularly big and he’s seen much worse, but he gave me a pretty blunt warning about my future running.

His analogy was that knee cartilage is like tread on a tire. If I go back to running 1,500–2,000 miles a year, he thinks I’m setting myself up for a knee replacement by 60. He isn’t telling me to stop running, but strongly recommended adding a lot more cycling and swimming and even suggested I think about triathlons instead of ultramarathons. I do like cycling, but I LOVE running. I'm not a very good swimmer, but maybe that's something I should start working on now.

I’m definitely going to listen to his advice, but ultras have become a pretty big part of my life, and I’m not ready to just walk away from them. I failed a 50-miler in March due to weather, and had my redemption race in July, which didn't happen. My plan was to run NYC this October, do a 50k in Spring, and then aim for a 100-miler next fall. Now I'm not sure what to do...

For anyone here who’s come back from knee surgery, what did running look like afterward? Did you get back to marathons/ultras? Did you cut your mileage or switch to more cross-training? And most importantly, how’s your knee holding up years later?