Sorry to say you damaged the logic on the edge of the LCD panel. What happens it the connections along the edge of the glass get damaged from the bang. Nothing here to fix, time for a new display assembly.
Follow this IFIXIT guide: [guide|7653|MacBook Pro 13" Unibody Late 2011 Display Replacement] if you're up to doing it your self. If you haven't worked on laptops before this maybe not the best project to start off on. Do you have a local Apple Store or Apple authorized service center?