Fusion Surgery: An Overview
Guest: Dr. John Glaser – Orthopedic Surgery
Host: Dr. Linda Austin – Psychiatry
Linda Austin: I’m Dr. Linda Austin. Today I’m interviewing Dr. John Glaser, who
is Professor of Orthopedic Surgery and an expert here, at MUSC, in spine
surgery. I want to get to the topic, Dr.
Glaser, of spine fusion surgery, but I have one basic question, first. A couple of different kinds of surgeons can
do spine surgery. Who is trained to the
kind of surgery you do?
John Glaser: That’s right. In general, the people who do spine surgery
are neurosurgeons or orthopedic surgeons.
There are a few crazed people out there who actually trained in
both. Historically, the orthopedic
surgeon would deal with the structural part of spine surgery, scoliosis or
spine fusions, and the neurosurgeons would deal with the decompression part of
Linda Austin: Decompression, meaning?
John Glaser: Such as a laminectomy for a
disc problem, or if someone had a spinal stenosis, a narrowing of the area for
the nerves. As time has gone on, the
orthopedic surgeons have expanded to doing much of the decompressive surgery,
and the neurosurgeons have often expanded to doing much of the structural
surgery. So, often times, many of my
neurosurgical colleagues may not agree, but we’re often interchangeable parts
for a majority of the problems that an average adult would have with their
Linda Austin: And, in that way, not
dissimilar from many areas of medicine, where, now, there are folks trained in
different specialties who can do similar sorts of procedures. Let’s talk now about spinal fusion, a very
common procedure. When is that surgery
indicated? Who gets that operation?
John Glaser: Spinal fusion is a
procedure to biologically weld two or more of the bones of the spine together
into one solid bone. The people who
generally get it are the people who have severe degeneration of their spine
with pain, so that it’s irritating nerves or causing deformity, or people who
have a deformity such as scoliosis of their spine. The other folks who will end up getting a
spine fusion are, for instance, people who have a disc problem in their neck,
where the procedure to take care of the disc problem is removal of the entire
disc. And, once you remove the entire
disc, if you don’t put something in there, the segment of the spine will
degenerate badly. So, most of the people
in that situation will end up with a spine fusion. And there are other somewhat more rare
things, if someone has a bad infection of their spine or a tumor of their spine
that needs be taken out, leaving them with a large gap, they end up with a
spine fusion to fill that.
Linda Austin: Can you describe that
operation, please? How do you go about
doing a fusion?
John Glaser: There are a lot of ways to
do the actual carpentry of the fusion.
The most common technique is done from the posterior part of the spine
or the back, where we go through the muscles or move them aside. We take the area of the spine and we roughen
it up. We remove the outer layer of bone
to get to the marrow elements where the cells that can help with the fusion are
found, and we add bone graft of some sort.
Or, more commonly, these days, a bone substitute or a processed donated
bone, which is not the patient’s own bone, so that we don’t have to take a bone
graft from somewhere else, we often will add some other factors to help it
heal, such as some proteins that can stimulate bone healing or some
instrumentation, some screws and rods to hold it rigidly in place. The primary biology is to get the bone to
bridge across from one of the vertebral bodies to the others so that they
become a solid piece of bone. The
thinking there is if it’s a solid piece of bone, it doesn’t move. If it doesn’t move, it shouldn’t hurt.
Linda Austin: And, is that, indeed, the
case? Do you see decreased pain in those
patients over time?
John Glaser: Most people will have a
decrease in pain, but very few are pain free.
We’re not good enough to make it normal.
Lind Austin: Is it possible, or
advisable, at times, to get more than one fusion, more than one segment fused?
John Glaser: Yes. There are times we’d have to fuse two or
three, four, or many segments, and that depends on the actual problem. For instance, people with scoliosis generally
need a large number of segments of their spine fused. For people who have the degenerative
problems, we do our best to limit the number of levels we do, although, at
times, we do have to do more levels.
Linda Austin: I would imagine that the
tradeoff, then, is a loss of flexibility, mobility, in the spine. Am I right about that?
John Glaser: Yes. You do lose some mobility of the spine. Many people, though, find that their mobility
is better than it was before surgery because they don’t hurt as much. They have less mobility than someone who is
normal, but more than they had prior to the surgery.
Linda Austin: Interesting. What are some adverse consequences of this
surgery? What are legitimate things to
be concerned about?
John Glaser: Well, the most common
problem, I think, of spine fusion surgery is that it just doesn’t make you feel
as good as you want to. We can have the
perfect patient who has the absolutely correct indications and an operation
that goes just fine, and they still hurt.
And sometimes we don’t know why.
Now, fortunately, that’s not very common, but it is one of the more
common problems we run into. There are,
of course, the standard potential complications from any surgery, infection and
bleeding. And, as you mentioned, the
loss of mobility can be bothersome for people who are quite active. The thing that is quite debated in the spine
world but, I think, can be a problem long term is if you take one segment of
the spine and make it stiff and solid, the stresses of everyday life are
transferred to the next segment up and the next segment down, and they wear out
faster than they normally would if you had not done a fusion.
Linda Austin: Are there age limits for
getting this surgery?
John Glaser: The most common age range
is about 40 to 60 years old. But I have
done spine fusion surgery on people into their late 80s and young teenagers, if
they need it. So, there really is not an
upper age range, as long as someone is healthy and able to tolerate the surgery
and is bad enough off to need it.
Linda Austin: What’s on the horizon in
this area? What are some of the newer
techniques and strategies?
John Glaser: There are some very
fascinating new proteins that have now been on the market for spine fusion, for
a number of years, for some indications.
They’re called bone morphogenetic proteins. These are proteins that are circulating in
everybody’s body in small amounts.
They’ve managed to purify them and manufacture them so we can now apply
them in surgery. There are two that are
now on the market, and they can stimulate the cells in the area where you place
them to turn to cells that form bone.
So, we believe they will increase our success rate of getting a solid
fusion when we do this. One of the complications
of spine fusion surgery is that the fusion doesn’t take and people don’t get
the solid bone. And we feel this is
going to significantly increase our success rate at getting this to solidly
Linda Austin: Dr. Glaser, thank you very
John Glaser: Well, thank you.
If you have any questions about the services
or programs offered at the Medical University of South
Carolina or if you would like to schedule an
appointment with one of our physicians, please call MUSC Health Connection: (843) 792-1414.