Your surgeon is probably right and they are swollen knee bursae.I am 10 months out on my right knee just had the left done this May and I have two lumps on my right knee that are a little squishy and I asked my surgeon about and he said it’s bursitis and that there’s nothing to be done with them. One is right on the tip of knee cap and the other is on the outer right side. They don’t cause me any pain. I am hoping maybe they will go away w time.
This article explains:
Baker's cysts and other knee bursae
New Zealand