It may work and it may not, but stems can be broken almost completely in half and then saved by taping it back up. It would be worth a shot, you will know in a few days if it is going to take or not.
Is your plant already in flower? If so how long has it been in flower? If it isn't in flower yet or is within the first couple weeks of flower then it really isn't a big deal at all, the plant will recover and your final yield should not be affected as much, the other shoots will grow bigger.
I know it isn't exactly the same but I had a puppy rip a freshly rooted clone out of a rockwool cube so that all the new roots were ripped off. I put more rooting hormone on it and put it in a new rockwool cube and it grew new roots all over again. If the top is not badly damaged...how about trying to make a clone from it?