DS,
Your post is almost the exact post I wrote a couple of months ago.  The
EXACT same thing happened to Lucy but it was her back toe that got caught.
Have you taken her to see a vet?  Please do so ASAP.  Lucy's toe was
actually dislocated instead of broken.  Her toe was splinted and her whole
foot up to her knee was bandaged for several weeks.  Now her toe is
completely healed and looks normal.  If you don't have her checked out by
her vet, the toes could grow back together wrong and be very uncomfortable
and/or awkward for her (not to mention painful until then).
 
As far as the cage is concerned, I used duct tape down the corners of the
cage to prevent that from happening again.  If your fuzzies are prone to
chewing on duct tape, you will have to try something else.  Sorry, don't
have any other ideas right now.  I felt it was sort of a freak accident
because Lucy usually climbs down more towards the middle of the cage rather
than at the corners, But now that the same thing as happened to your
ferret, maybe it isn't such a freak accident afterall.  Feel free to e-mail
me if you have any questions, but PLEASE take her to the vet!
 
Barb, Lucy & Greta
 
P.S.  I think I have a Marshalls cage.
 
"Resolve to be tender with the young, compassionate with the old,
sympathetic with the struggling, and tolerant of the weak and
wrong...because sometime in your life you will have been all of these"
[Posted in FML issue 2622]