I am 12 days post surgery of a partial knee
Thoughts on this
If the swelling is about the same as before or decreasing slightly, it may just need more time to recover. However if the swelling is increasing, particularly below the level of the knee, it can mean that there is a deep vein thrombosis, and this should be checked out, typically with doppler imaging.
If the swelling is in the same area as the rash, it could be swelling due to an allergic reaction. Is the rash itchy? Painful? And by raised, do you mean small papules or wheels as in hives?