Learning German some 25 years ago we used to use words like "gebrötchen" to mean "a bread roll I had just eaten".
It was funny at the time.
I obviously like bad 'jokes' like that, but it can't have escaped your attention that participlisation doesn't work with a pure noun. :) It would have to include the full participle, e.g. "Gegessenesbrötchen", which you might as well write the way it's intended, as "gegessenes Brötchen".
Let's by all means keep this up for three pages now that the knee topic no longer has legs. I'm sure russmeyer will be enchanted. :)