It's not a standard expression.
When something breaks (physically into more than one piece), almost by definition you can't put it together again. A broken plate, a broken egg, a broken leg -- they will always be in pieces. Even if you are able to glue the plate together or when the bone eventually knits back together, you'll see the line where the pieces were.
Only magic can "unbreak" something as though it never happened.
(That's the implication.)
Student or Learner