I had the medial meniscus removed in my right knee over 30 years ago in response to a completely torn medial collateral ligament and a stretched and partially torn ACL. I was only 20 at the time, and I didn’t realize that the meniscus had been removed.
I took up ultrarunning and marathoning about 10 years ago, but had to stop due to pain in my ankle. Turned out I had developed arthritis in both the knee and ankle. I had surgery on the ankle in early 2007, and it’s a lot better now. I saw a couple of good orthopaedists about the knee, and both said knee replacement, or live with it. Apparently, the cartilage is gone in the medial compartment.
I found that weight training has helped with the pain I was experiencing in the knee. Strengthening the muscles around the joint helped.
As best I can figure, the removal of the meniscus changed the angle of the lower leg which put additional stress on the ankle, and that’s what led to the ankle problem. The lack of the meniscus eventually led to the deterioration of the cartilage in the knee. I battled a weight problem throughout that whole distance running phase, which I’m sure didn’t help anything.
One thing that they can do is to put you in a valgus unloading brace. This puts a torque on your knee which tends to bend the lower leg out (in the case of a medial meniscus removal). They suggested this for me.
So anyway, I hope some of this helps. If I had known then what I know now, I would have worked more on keeping my weight down, and maybe run less as well.