The best thing to do is to use whatever works to make a clean sharp cut below where the tree is broken. It will sprout again where there is a bud...
so where a branch was, or is. In other words look for a knob where there is or was a branch. Cut the truck clean just above the knob. The tree will grow from that knob. You would be surprised how resulient trees can be if they get water. I planted a nice Mimosa tree in my son's yard. A neighbor child climbed on it when it was too small and it cracked in a V between the only two branches. I could not find anything but duct tape, so I taped it up and then tied rope around both branches to hold them up. I expected the entire trtree to die. To my surprise a year later it was still taped and both branches living. It is now 3 years later. The tape fell off. my son took off the rope and although I can see the crack, the tree healed all around the crack and now is very bog a strong. If your maple does not sprout from a bud on the truck, it will start a new bud from the ground.
JoAnne D.
September 2009