Taking backup of DB does not mean that, just copying all the files physically when the Database is up and running. So is the problem you are facing when you want to recover it. Only the way is recreate it and import. But atleast make sure that you follow the procedure to have a nice backup right from now.

Like having a clean cold backup, or having a hotbackup which needs to be done with systematic procedure. If you want I will post you some sample script