J. Brett Gentry, M.D. • Dennis A. Ice, M.D. • Wayne S. Paullus Jr., M.D.
806-353-6400 • 800-658-6636 • 1000 S. Coulter • Amarillo, Texas
Minimally Invasive Spine Surgery: Case Study
For some patients with serious spondylolisthesis, degenerative disc disease, or nerve
compression with associated low back pain, fusion surgery is the treatment of choice. Fusion
surgery involves joining or fusing two or more vertebrae together. PLIF and TLIF are two
different types of fusion surgery that can be effective treatments for these conditions.
PLIF versus TLIF
Posterior Lumbar Interbody Fusion (PLIF) is a common surgical technique used to treat the
conditions mentioned above. In this procedure, bone graft, or a bone graft substitute, is placed
between vertebrae in order to fuse them and create a stronger and more stable spine. The
bone graft is inserted into the disc space from the back (posterior). In addition, spinal
instrumentation such as screws and rods are used to hold the spine in position and help
promote successful fusion.
In recent years, many surgeons have begun to use a TLIF procedure (Transforaminal Lumbar
Interbody Fusion) in preference to a PLIF. A TLIF can accomplish the same goals as a PLIF
procedure. However, in TLIF the surgeon inserts the bone graft into the disc space from the
side. This results in the nerve roots being moved less during the procedure, as compared to a
PLIF, and may reduce the risk of scarring or damaging the nerve roots.
Open Versus Minimally Invasive
Traditionally, TLIF has been performed as an "open" technique, which requires making a larger
incision along the middle of the back. Through this incision, the surgeon then cuts away, or
retracts, spinal muscles and tissue to access the vertebrae and disc space. The cutting and
retracting of muscle and tissue is part of the reason that after the operation, patients are faced
with a long recovery period of several weeks or months.
Today there is a minimally invasive TLIF technique that is proving to be an effective alternative
to "open" fusion surgery. In a minimally invasive TLIF, the surgeon inserts a small tube through
the skin until it "rests" on the spine. Using special surgical instruments the surgeon then does
the entire TLIF procedure through the tube. Working through the small tube, instead of a larger
"open" incision, greatly reduces the amount of muscle and tissue that is cut or retracted. Blood
loss is dramatically reduced. These minimally invasive benefits also lead to shorter hospital
stays and quicker patient recovery times.
A Recent Study
A recent study of 49 minimally invasive TLIF operations has shown excellent results. This
study included 19 men and 30 women. Forty-five of the patients suffered from both mechanical
low back pain (related to the body's movement) and radicular pain (from pinched nerve roots)
in their legs. The remaining patients had low back pain alone. Eleven of these patients had had
previous surgeries at the same levels of the spine.
After their procedures, all 45 patients with both back and leg pain reported improvement of
their symptoms. The four patients with mechanical low back pain alone reported a decrease in
their pain. In addition, 18 months after their surgeries, all of these patients had solid,
successful fusions. The average hospital stay for these patients was 1.9 days. The patients
seemed to have less post-operative pain than for an open procedure, with narcotic pain relief
medications discontinued 2-4 weeks post-operatively.
Case Study - Meet Ray
Ray is a 55-year old man who suffered with severe low back and leg pain from
spondylolisthesis and spinal stenosis at L4-5. Figure 1 shows the spondylolisthesis (forward
slippage of L4 on L5, arrow) and Figure 2 shows the spinal stenosis (small spinal canal, center
arrow).
Figure 1. Spondylolisthesis
Ray's surgeon performed a minimally invasive TLIF through a METRx™ tubular retractor, using a oneinch incision (Figure 3).
Figure 3. METRx™ Tubular Retractor
SEXTANT™ screws and rods were used to hold the spine in position and were placed through
this same incision and a second one on the opposite side of Ray's back (Figure 4).
Figure 4. SEXTANT™ screws and rods stabilize the spine.
Pictures taken before and immediately after surgery show how well Ray's spine was realigned
(Figure 5). There were no complications and Ray was discharged from the hospital 2 days
after the procedure and returned to work three weeks later.
Figure 5. Pre- and post-operative images.
At his examination 2 years after his surgery, Ray was doing well and reported no back or leg
pain. His small incisions were barely visible (Figure 6).
Figure 6. Small incisions are barely visible.
The Future
The use and effectiveness of minimally invasive TLIF are still being studied. However, the
initial results of this innovative procedure look very promising. Stay tuned!