I had one knee replaced and both legs were swollen from hip to toe. They gradually went down in three to six months. My surgeon said it was normal. I exercised and iced my replaced knee which went down more slowly. Physical Therapist also used athlete tape in strips diagonally down my knee and ankle. Don't know how that works but it did.

@lotsofpain I was having some swelling from fluid retention in my R leg and I was told to wear compression stockings. I asked if they did anything beyond helping my leg to not puff up as much by nighttime and was told that they do. I had three different ultrasound tests done on my leg but none showed anything so the nurse practitioner I saw suggested it was "Chronic Venous Disease".

I can't recall exactly what the benefit was but I do remember that it impressed me enough that it made me more conscientious of wearing compression stockings for the problem. It was just one leg and now it seems to have recovered.

I found an article about the benefits of compression stockings:
https://health.clevelandclinic.org/what-you-should-know-about-compression-socks/
The first time I got some I went to a pharmacy that actually measured your legs and fit them to you but you can measure your own legs and buy that brand (Jobst) online too. I liked the ones that go up to the thigh because my legs are sort of short and a bit heavy so the knee-high high-compression ones would bind me below the knee.

If you want just light compression and knee-high though I have also had luck with the Dr. Motion brand that can be purchased at Target, Kohl's, and Amazon. They come in patterns, dots, etc. so are not medical looking. Even my old PCP commented on them being nice! Being a lighter compression they don't hurt at my knee. I pretty much wear them all of the time except in the summer when I have sandals on.
JK