Total Disc Replacement
Spinal surgery is presently undergoing radical changes. Surgical
options for patients previously told to live with their pain may
now provide relief and resumption of active and enjoyable lifestyles.
This technology is predicated on the disc as a major source of
pain generation. Patients suffering from disc related pain may
have been given various diagnoses, such as degenerative disc disease,
lumbar spondylosis, annular tears, central disc herniations, vacuum
disc degeneration, disc protrusions, etc. The clinical symptoms
are characterized by severe at times, excruciating low back pain
with activity, particularly repetitive bending, sitting, driving
in a car, or twisting.
The lumbar disc as a source of pain began with the now famous
Mixter and Barr New England Journal of Medicine article that began
the era of discectomy surgery. However, what initially was perceived
as a panacea for back pain met with inconsistent results for back
pain relief. Over time, patients with disc pathology were felt
to be ideal surgical candidates, only if they experienced mostly
buttock and leg pain in the face of correlative imaging studies.
Patients experiencing mostly back pain were soon discovered not
to be ideal surgical candidates, with many experiencing worse pain
after surgical discectomy. This led many physicians away from regarding
the disc of a primary pain generator. Shrouding the disc in more
controversy were the occasional patients who benefited from posterolateral
fusion surgery. Why had some patients benefited while others did
not? Again, inconsistency led many physicians away from the disc
and in many cases; back patients began being regarded as chronic
complainers who never seemed to improve, despite technically well-performed
surgeries. Why posterolateral stabilization with or without hardware
could provide consistent back pain relief has been a major point
of contention among spinal specialists.
Fortunately, interbody fusion devices, although flawed in design,
focused attention back to the disc as a major pain generator. Physicians
recognized the excellent early results with interbody cages and
their application became immensely popular. Unfortunately, the
interbody space required more preparation than drilling cylindrical
cages into it to allow a solid interbody fusion, and late failure
6-8 months post op plagued many spinal surgeries. However, because
of the metallic artifact of the interbody cages, especially if
augmented with pedicle screw fixation, radiographic images became
nearly impossible to interpret. Patients were frequently imaged
and told everything looks as it did after implantation and therefore
could not be implicated as the source of their recurrent pain.
This gradually led to more conflict and confusion regarding surgical
indications for fusions and the inconsistent results despite technically
well-performed surgeries.
The advent of total disc replacement and nuclear replacement again
properly focuses spinal specialists on the disc as a primary pain
generator. This technology, if properly applied, may provide another
valuable tool for some specialists to utilize. Patient selection
as in most procedures will be critical, and an understanding of
the source of the pain generator is critical before indicating
any patient for a spinal procedure. For these reasons, the physicians
at the New Jersey Spine Institute, P.A. feel uniquely qualified to evaluate
and educate patients in order to provide a diagnosis and treatment
regimen specifically addressing the patient’s pain generator,
rather than adopting technology as it appears in the tabloid in
a haphazard fashion without the necessary understanding of its
indications.
We have always felt that the importance of new technology and
the procedures which this technology generates, should be rigorously
tested against existing technologies. For example, interbody threaded
cages were never adopted for more than a hand full of cases. In
comparison to the interbody fusion done with threaded bone dowels,
horizontally oriented titanium cages pale in comparison for clinical
success. We have in fact revised many horizontally oriented titanium
cages with clinical success. |
