A Baker's cyst is a fluid filled sack that forms in the soft spot behind your knee. Usually they are a result of some pathology within the knee itself. Therefore, simply addressing the cyst, without treating the knee issue, will probably be inadequate. Once the knee problem is corrected, the cyst usually goes away on its own
I had a Bakers Cyst removed a couple of years ago - small surgical procedure. They are fluid filled sacs from what I was told. I had it drained several years ago but it refilled with fluid. I can't say I notice any symptoms of it returning or filling again. Mine would get larger when I was extremely active and get smaller the less active I became.
They are a nuisance aren't they?