I was seeing an orthopedic doc for arthritis since last fall, then only a couple of months ago learned I have a couple plasmacytomas and am fixing to start with a MM specialist in a couple of weeks (following two months of local testing, got referred to a nearby specialty center)
There turned out to be newer, more intense/acute pain in one knee, but only recently was I concerned about the possibility of other lesions elsewhere and that it could be related. An x-ray did show small lesions and we are going to do an MRI to see what may/may not be going on.
So I would say if your "regular" arthritis pain intensifies, feels different, etc., consult with your care team.