Joint replacement

Ive had both hips replaced and it was such a relief although I e never fully regain balance so use a rollator for longer walks and shopping a a stick at home.
Ive just been told I have arthritis in my knee. Am coping with co codamol at present and gp suggested steroid injections when meds dont help. My question is has anyone had a knee replaced when both hips are already done?? If yes, how did you cope. I know we are all different