If "rotating" refers to pedaling, I had a similar thing except I found it too painful to do a complete rotation even backward. I used my good leg to push backward until my bad knee was as far up as I wanted, then used the sore leg to push back down forward with some resistance dialed into their bike. I only did complete rotations by accident, and usually experienced a sharp pain when I did. I can go all the way around now, though.
I have two instructor buddies who had total knees done last fall. The one who is six months younger than I--he just turned 71--continues to have some limitations, partly because he needs the other knee done and he's having trouble adjusting to walking correctly because he hobbled so long. The one who's six years younger pushed himself to tears in therapy and is basically unlimited now. Both got back onto skis this spring, however.