Will they put a cast on a broken and dislocated pinky finger?

Depends...: A fracture on the end of the finger can be splinted easier than those close to the hand. The closer you get to the hand the higher your chances for a cast. There are various types of fracutres that can occur with a dislocation and some are more severe than others. Some may require simple splinting, and others may require surgery. Can you provide more specifics about your individual situation?