you can use that opportunity and cut the stem a bit more. If you dont want to, i can understand but i would still put tooth sticks in there. Thats a trainingtechnique but forgot the name. You can also just skip on that and simply repair it.
Before you put toothsticks or if u simply want to repair. i would apply one cabletie underneath the damage so it doesnt get worse and up above you can use a thick thread, bind it around both branches and the middle top inbetween like an 8 or simply around both branches, you can put a lot thread there till it looks like a ball. so press the 2 branches together that will pressure the wound together by itself.