The only variation is that "La" can, optionally, be changed to "L'" before or after a vowel. Offhand, I don't recall any title starting with "L'". Fortunately, there is no case or gender variation in the definite article, and there is no indefinite article in Esperanto. So the only thing to deal with is "La" or (conceivably) "L'".
This is admittedly in the "not a big deal" category.