I was doing a little bit of reading about osteoarthritis that leaves me
confused about what seems like it must be the central issue of the
disease.  On one hand, all conventional wisdom seems to agree that
cartilage virtually "doesn't heal", and that osteoarthritis results
from a cumulative "wearing away" of joints over a lifetime.  Yet it is
also acknowledged that different individuals with the same life-style
have wildly differing degrees of osteoarthritis, which seems strange
for a solely mechanical process.

On the other hand, it seems that cartilage transplantation is a very
hot topic of research, and that plugs of cartilage tissue are expected
to grow and fuse into the articular cartilage!  True, these may use
more cellularized tissue grown in vitro, but the in vitro manipulation
doesn't seem excessively sophisticated.  It's thought that treatments
like collagenase or hyaluronidase can increase the regeneration
potential of the plugs, but these enzymes are secreted as a part of the
normal inflammation process which undoubtedly occurs in arthritic
joints.  Of course, all processes of regeneration slow down with
cellular senescence - but they never stop completely.

I'm curious what people think of this apparent paradox.  I'm no expert
on arthritis, but my gut feeling is that there ought to be a way for
some new drug (together with rest, nutrition, and other therapies meant
to reduce strain on the joint) to let a person's arthritic joints to
"catch up" with the wear and tear they have suffered, without the need
for radical surgical intervention.  In theory, anyway - I'm not
pretending that there aren't a lot of people in pain who don't
currently see any other options.  But it'd sure be fun to come out with
that drug!