Because of the "curse" pronounced on all Creation, our bodies are not perfect. We wear out, we break down, and finally, we die.
Our bones are no exception.
Joints continue to break down because of imperfect lubrication, or more
serious structural defects. If our bones were made of metal, most
repairs would involve a spot
of welding, or a new set of bearings, but bone
is not metal.
There are no non-body materials which are
fully compatible with the tissues and fluids
which move in and around bone. There are
also no man-made lubrication systems which
can survive the work load in the human body.
For example, bone is
able to stretch up to ten times the distance as steel, so fixing a
steel part to a bone is going to place some serious stress on the
bone-metal interface.
Some modern materials come close to
bone. These materials combine plastics,
with glass or other fibres combined,
but there is always deterioration over time, and quite often the new
part has to be replaced again.
"And
Adam said, This is now bone of my bones, and flesh of my flesh: she
shall be called Woman, because she was taken out of Man." Gen 2:23
Interestingly, bone from the rib is able to regrow completely when it is removed.
Eve was formed from Adam's rib bone.
