If you can get the loose hinges out of both surfaces I would replace them with new ones. If the new hinges slide into the old slots it should be fine, otherwise make new slots. If the hinges only came loose from one surface and you can't get them out of the other, check to make sure they are still good and just re-glue them. You may want to double check all the other hinges for tightness while you are at it. What ever you end up doing, just make sure you can't pull them apart after the CA cures.