Knee injury in the time of corona

As a fellow bad knee sufferer, my recommendation would be to work on strengthening the knee and all of the assorted muscles (e.g., hips, glutes) that stabilize the knee / contribute to strain on the knee if they are weak.

If you can, work with a PT to get a plan of exercises, and do them consistently.

If you cannot get to a PT, Jonathan’s long post [FAQ] How to Fix Knee Injuries for Cyclists (Knee Pain) is a good place to start / get ideas.