Many moons ago flew trans-Pacific (my own money...) on CO next to a HUGE woman, who also had support bandages on both her knees. I literally had half a seat, and could not use one end of my seat belt. I was constantly harrassed by the CC to either buckle up (fine, show me how....), or to stop standing around (I could only sit sideways - turning the other cheek, so to speak). The CC could not look me in the eye when I left the plane.
Wrote to CO and the FAA afterwards - didn't even get a reply ( well, I am an alien). Have never used CO again, and never will....