My dad lost the top of his finger due to a very similar scenario to that of the one you described. He's lucky that was the only thing that happened to get "in the way" and squished. Crazy part is, they were able to reconstruct it. Initially he was just going to get the bone filed down, and have a shorter finger, but the doctor he was dealing with was a bit of an arrogant prick. So he went to someone else. They ended up opening up the finger beside the injured one, inserted the injured one into the other and sewed it up for a couple of months. He had this big boxing glove type cast.... Couple months later they cut the two fingers apart, and I guess the skin must have "grafted" (or whatever you call it) onto the injured one, and he literally had his finger back. The nail even grew back! Crazy shit!.... Somehow I don't think the procedure would go so smoothly for a leg however...