My thought was that it could just match ^\d*?(?=-) and ignore the title. I think the adantage of the dash over a separate parameter is that it would look more compact and the advantage over achors is that it does not misuse the URL semantics ("The fragment identifier #fragment, if present, specifies a part or a position within the overall resource or document"). And the title is an identifier of the item, so it would still make sense regarding the semantics of the id-parameter.
Search engine spiders, scrapers, etc. would end up hitting a bunch of dupes when the title change causes a new URL to be generated that really points to the same content (not that spiders don't already have to deal with that mess on other websites).
HTML headers can include a `<link rel="canonical" …>` that points to the up-to-date URL of this item. Furthermore, outdated or invalid titles could be redirected with a "301 moved permanently" to the current title.
