From all the reading I've done on foot-binding in China it seems as though it was done on young girls, presumably because their bodies could tolerate it better.
Do we know if it was ever attempted with adult women whose bones were fully developed, and what the outcomes were if so?
There have been no adult cases in China during that period to my knowledge but there have been three recent cases of this:
There was an American woman called Nancy Luna (who is mainly a contortionist) who appeared on 'Ripley's Believe it or Not!' second episode of the first season (aired January 19, 2000). No bones were broken in her foot so nothing drastic changed in the long term. She also appeared in a body modification magazine but I don't have any access to it.
Another case is oddly enough a man, who is in his mid twenties. He did it just so he can fit into smaller shoes. Having seen pictures though, his feet don't resemble the lotus flower but is somewhat deformed nonetheless. www.dailymail.co.uk/femail/article-3647169/Body-obsessed-man-hated-big-clown-feet-reveals-binding-two-years-THREE-TIMES-smaller.html
Lastly is the most drastic one, referred to as Mrs SM, is a young woman in her 20's who lives in China. I couldn't track down the original article but the pictures from it are in the following video. The translated text from it is also in the description. If the pictures are anything to go by, her foot looks closest to the bound foot. www.liveleak.com/view?i=206_1412186201
That's all that I know of, its obviously extremely rare for anyone to continue the practice.
I know this doesn't exactly answer your question but it does describe what a bound foot is like when the process is started from adulthood. Which is discovered to be rather difficult to achieve.