Splinting the lower leg bones is simple and effective; you just immobilize
the break as well as the closest top and bottom joints, and that is all
there is to it.  Upper limb bones are a different matter.  While humans
tolerate body casts to immobilize the shoulder or pelvic joints, most
animals do not, so using a splint is difficult.  In those cases (and even
for humans), the best solution is to pin or plate the bone, which requires
surgery.  When you pin a bone, you basically drill a hole and push a rod
(or pin) down through the marrow space; this acts like a dowel to hold the
broken ends together.  A plate is a small piece of metal which is directly
screwed to both ends of the bone, like a joiner plate holding two sections
of rail together.  In ferrets, the bones are so small (not in size, but in
thinness of the compacta which supports the screws holding the plate), that
plates are difficult to use, and pinning is generally preferred.  In some
cases, the bone is so fragmented that neither pinning or plating will
work, and sometimes wire is used to "sew" or "wrap" the larger fragments
together.  Sometimes these devices are left in the ferret, but often they
are removed later.  The best part about plating or pinning is the ferret
can usually use the limb in a few days.
 
Sometimes a ferret cannot risk surgery, and the bone cannot be splinted.
The best solution is simply quiet rest.  The bone will typically heal well
enough on it's own, believe it or not (that's how wild animals get by
without vets).  This happens much more often than you might think; when a
ferret breaks a bone, but it is not always noticed by the owner.  It also
happened to my Bear.  When Bear was a few months old, he fell on his hip,
pushing the head of his femur through the cup in the pelvis that holds
it (the acetabulum).  The tiny bone fragment from the acetabulum hid the
fracture to the head of his femur, which wasn't noticed until it was mostly
healed.  Because the treatment was a couple of weeks of enforced bedrest,
the bones healed fine, and while Bear now has hip problems (he has
reinjured the hip twice), they are probably no more than what would have
been expected if surgery was done.  It important to closely monitor the
situation, watching for signs of infection, the bone being moved out of
position, or other problems.  And even if this is the course of action you
are forced to take, make sure a vet is involved from the onset.  You need
an x-ray to make sure the bones are properly aligned, and vets are trained
to look for the slightest sign of infection and can get immediately
involved if the situation warrants action.
[Posted in FML issue 3436]