Story ident - Demon sleeps with disabled woman, cures her disability

A man possessed by a demon, or maybe the Devil himself actually, is left alone with a woman who is severly disabled. They have sex and by the end, she is no longer disabled.

I think this might be an older British movie, from the 70s perhaps.

I remember it being very short though, too short for a movie but I don't think it was an episode of a TV show. The story seems a bit much for something like the outer limits.

Does this sound familiar to anyone?