There are federal laws regarding health issues for employers/employees. In lots of situations the employers must provide the items needed so employee can work. See your HR dept. with a note from dr. regarding any needed accomodations.....if can't stand all the shift perhaps a tall stool can be provided. Knee surgery now is nothing like it used to be. I get weepy and scared at thought of surgery, but also know as soon as I get to hospital if I am weepy they bring on the medication. One anethesiologist gave me an IV before I got to the operating room. She asked if I wanted happy juice. I was so glad to go ahead and get the IV. When you wake up you are on the road to recovery. Prayers for peace, comfort, strength & speedy healing. HUGS....