Low impact. Swimming or water based exercise are best. Stationary bike and elliptical are also good choices. Avoid high impact activity such as running and jumping.
Is knee cartilage damage painful? My knee has been feeling discomfort for 2 weeks, but it goes away when I forget about it. No pain, I can walk.
Depends. Knee cartilage damage can indeed be painful but this depends of the severity of the damage and your overall health and the time since the damage occurred. If you aren't having any significant pain then it's likely nothing to worry about, but do see a physician if symptoms worsen or persist.
Have knee cartilage damage. One doc wants to do microfracture but another says oats--allograft kind. How do I decide?
No right answer. Both can work might want to get a third opinion or even more.
Microfracture. Microfracture is appropriate for any defect less than 1 cm. Oats allograft is appropriate for any defects greater than two and 1/2 cm. Autograft oats is usually appropriate in between these sizes. Try discussing your options with your surgeon. Best of luck!