And I assume these are provided to let user share links to individual posts in a thread.
In a large forum there would be cases when threads are merged/split/moved... these links shared at external sources might not remain accurate (though you might already be using redirects to their new position on the forum making the point of this thread invalid but still...).
My worthless suggestion is to link the permalinks with absolute links instead. These links are already used in the news feed section.
I am going to post sample links after posting this thread. I hope I have managed to explain my trivial point here!