Rob Lowe is still not over losing the lead role of Ren McCormack in ‘Footloose’ to Kevin Bacon. The 59-year-old actor was left gutted when his knee “exploded” trying to nail a key dance move in the 1984 musical classic. The producers then decided they needed to hire a professional dancer, only to cast Kevin Bacon, 65, a week later. He told USA Today: “The thing that’s awful about it was, I was the guy. I was going to get this part. I just had to do the dance, which was to a Styx song, by the way. Not helpful. But it ended with that drop-to-your-knees slide across the floor. My knee just explod…