With 80 percent of adult Americans sustaining at least
one episode of severe disabling lumbar back pain in
their lives, lumbar surgical treatment alternatives are
always in the news. Approximately 85 percent of these patients
will improve with non-surgical interventions in the form of physical
therapy, medications, pain management, or a significant
lifestyle change. The remaining patients may be left with surgical
decisions to alleviate their lumbar symptoms.
Have the surgical options changed? Indeed they have. A myriad of
new surgical techniques and a pipeline of new technologies are being
developed. Not all can be addressed in this short article, so we will concentrate
on some of the newer and more efficacious surgical advances.
For patients who present with symptoms of lower extremity radicular
pain or sciatica due to lumbar herniated nucleosus pulposus (HNP) or
stenosis, a minimally invasive posterior approach is frequently recommended.
The procedure, termed MITR (minimal invasive tubular retraction), uses
a 16 mm to 18 mm skin incision with a series of cannulated tubes docked
onto the appropriate intervertebral space. The exact position and location is
verified by fluoroscopic guidance. The decompression procedure is then
usually accomplished with the aid of an operating microscope and specialized
instrumentation through this cannulated apparatus. Lumbar disc fragments,
synovial cysts, or osteophytic stenotic lesions can be treated in this manner in one or two level procedures. Most
patients obtain a 90 percent to 95 percent improvement
in their symptoms.
Significant advantages of this procedure include
minimal tissue destruction, the fact that it can be
performed in an outpatient surgical center, and
patients often are able to return to light work activities
within three to seven days. A majority of
patients have a successful outcome from this minimally
invasive procedure that avoids the increased
morbidity and pain of an open procedure.
Lumbar fusion procedures for various instabilities
have been greatly improved by the emergence
of new osteoinductive biologic products. The
most notable is bone morphogenic protein, or
rhBMP-2. This peptide is commercially available
as INFUSE®, and is FDA approved for several musculoskeleletal
indications. As an osteoinductive
agent, it is one million times more biologically
active than autologous iliac crest graft. Patients
who need spinal fusion but are at high risk for
non-union may achieve successful arthrodesis and
avoid donor site morbidity with the use of BMP.
The emergence of new spinal instrumentation,
implant technology, and biologics such as BMP
open the door to minimally invasive fusions
for selected patients. The advantages of neural
decompression accomplished through a minimal
posterior approach include minimal tissue dissection
and denervation. This significantly reduces
the infection rate, post-op pain, and the duration
of hospitalization. Already a number of patients
have benefited from this.
However, there are disadvantages to this new
approach. The greatest is a steep surgical learning
curve for new surgeons. Also, some of the available
percutaneous posterior instrumentation systems are
awkward and cost-prohibitive to hospitals.
As a solution to some of these difficulties, a
stand-alone interbody implant is being developed
to reduce the need for these posterior segmental fixation
devices. This technological improvement
offers the possibility of outpatient fusions in the
very near future. Having personally performed minimal
invasive lumbar fusions with current technologies,
the difference in short- and long-term recovery
for patients is truly remarkable when compared to
current open techniques.
Total disc replacement is a promising development
in the treatment of severe lumbar back pain
in patients with degenerative disc disease. It is
indicated in younger patients with one level disc
disease who have clinical and diagnostic findings
of lower lumbar degenerative disc disease. The
Charité artificial disc was approved by the FDA
in 2004, and the Prodisc in 2006. In selected
patients, implants are inserted through an anterior
retroperitoneal approach, creating an artificial
disc at that segment. Ideally, motion is preserved,
avoiding such fusion problems as adjacent level
disc and facet degeneration. This has been a longterm
problem in many fusion patients who may
require repeated fusions for adjacent level degeneration
or instability.
While the theoretical advantages of artificial discs
are evident, there remain important questions
regarding patient selection, early adverse events,
and the uncertain long term clinical outcomes. I
feel that continued improvement in artificial disc
implant technology will occur with better generations
of artificial discs ahead, much as was seen in
the evolution of total joint arthroplasty.
For older patients with severe spinal stenosis creating
significant lumbar back pain and neurogenic
claudication of their lower extremities, a promising,
less-invasive surgical procedure exists. The FDA
approved the X-Stop device in 2005, which is an
implant placed between spinous processes to prevent
extension of the spine at the symptomatic
level. This effectively unloads the respective motion
segment and increases spinal canal diameter and
foraminal height at this level, thereby indirectly
decompressing the stenotic nerve root. This avoids
any laminectomy or laminotomy procedure and
may be ideal for the patient unable to undergo a
more invasive surgical procedure due to significant
over-riding comorbidities.
This represents a new technology. There are no
long-term prospective randomized studies that represent
its long-term success, but there are some studies showing a higher re-operation rate due
to dislodgement of the implant. I feel it
will not replace the “gold standard” of
decompressive laminectomy for those
patients who can tolerate the more
invasive procedure.
We have reviewed some of the
recent advances in technology and
lumbar spinal surgery. The scope of
this article, however, is limited, and the
advances discussed are not intended to
be comprehensive. As in other surgical
specialties, minimal invasive surgical
techniques are currently available in
lumbar surgery. With new advances,
the surgical outcomes for future
patients remain bright.
Patients often recount a relative’s
earlier experience with lumbar spinal
surgery. They are apprehensive about
lumbar surgery due to some of the
extended recovery periods their relatives
incurred. With the advent of minimally
invasive lumbar surgery, their
concerns are greatly alleviated. At the
conclusion of the surgical consultation,
I remind them: “Remember, it is not
your father’s back surgery anymore.”
My prospective surgical patients seem
to find this comforting.
Paul T. Geibel, MD
earned his M.D. degree
from Tulane University
School of Medicine in
1983. His postgraduate
training included serving
as Orthopaedic
Chief Resident at
Tulane Medical Center and Charity
Hospital, New Orleans. After residency
training, he entered the Spinal Fellowship
program at the University of Louisville,
Leatherman Spine Clinic in Louisville,
Kentucky, and the Tulane Spine Fellowship
in New Orleans. He has served as Clinical
Instructor and Assistant Clinical Professor
of Orthopaedic at the University of Texas
Health Science Center at San Antonio.
Currently he serves as Chairman of the
Department of Orthopaedic at Southwest
Methodist Hospital and is the lead investigator
of clinical studies with interbody
fusions and Bone Morphogenic Protein
(BMP). Dr. Geibel may be contacted at
ptgeibel@spinaldoc.com or at 210-293-2921. His office is at 18626 Hardy Oak
Blvd, No. 300, San Antonio, TX 78258.
