Any chance of getting an appointment with your gynaecologist as well, and / or with a physiotherapist, if you are not seeing one regularly?
Physiotherapy might just help both the arthiritis and the pelvic issues and even the slightest improvement would be a help.
I had trouble with bladder control and feared a prolapse, but as it turned out, I had a massive benign cyst on my left ovary and not the fibroids four different gynaecologists had thought were the problem. Not their fault either, as the ovarian cyst had weighed the ovary down to such and extent that it was in front of the uterus, so the cyst appeared to be a fibroid inside the uterus on the scans.
Having both ovaries removed, solved the problem with bladder control.
I hope you could be just as fortunate, if your consultants reach the right conclusion.