When I had a severely sprained ankle, I used speedplay pedals, which allowed me to be basically pain-free. Though, I did have to ride with my right foot clipped in the entire time and take my foot out of my shoe with the shoe still clipped on when I got home.
I'm wondering the same thing as Deb- my problem was that my foot needed to float freely, and I could not torque it to unclip, so the speedplay/never unclip strategy worked for me.