I agree that re-staking it would seem the best course of action.
From what I gather the stem is bent but the root-ball is stable, in this case, it should be better to support the stem above the bend, in the hope that it may build re-action wood at the point of the damage.
If on the other hand, the wood is splintered and delaminated, you could try sawing the stem off below the break, and it might sprout some new growth at the point where you have cut.
Difficult to tell realy without seeing it, to be honest.