Pain behind knee

Liked: 1 View Profile Personal Message (Online) Pain behind knee I am having trouble with my left knee. Pain at back of my knee after sitting down and while going up or down stairs. Any ideas what this could be? I had a microfracture on my right knee November 2019 which has also started hurting again. I will go to the doctors when I can but with covid i don't want to bother them at the moment