Hi,
The USB port in the camera may have broken off the board because of the fall, (or perhaps some other component relating to the USB function).
Have you tried removing the SD Card and inserting it into a card reader connected to your PC and downloading (copying) your photos directly that way.
If you try opening the camera to find out what the problem is you could cause more problems. If this is the only problem with the camera and you can download (copy) your pictures using the method above, then leave it as is.