Leave it alone. The crown, if it is still opened, will grow a new tube and settle down. I have a purple and a orange. The purple one suffered several injuries and is still alive. In fact, I cleaned my tank 2 months ago, and I found 3 purples (I only bought one). Either the tube anemone split, OR, the injuries forced the anemone to split.
BTW, the tube anemone appreciates bits of seafood from time to time.