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Minimally Invasive Spine Surgery is the use of small
incisions, meticulous tissue handling and the latest microscopic technologies to
do operations that i the past would have required large incisions and extended
recoveries.
This technology can be applied to:
1. Lumbar decompressions
2. Anterior
cervical fusions
3. Posterior
cervical foraminotomies
4. Some lumbar fusions
To illustrate a case in point the following was described
on the SpineUniverse website:
SpineUniverse Case Report:
Minimal Access Spinal Technologies (MAST) Fusion for Osteomyelitis
HISTORY
This
84 year old man was initially reviewed in September 2001 after having
had a laminectomy performed by an outside institution for presumed
spinal stenosis. He had had a poor outcome from the surgery in terms of
hip and thigh pain and postoperative MR scanning at that time confirmed
multiple lesions throughout the lumbosacral spine, which on CT-guided
biopsy confirmed underlying metastatic prostate cancer. He was managed
non-surgically with appropriate chemotherapy and radiotherapy.
This
man presented in April 2003 with severe mechanical back pain, in the
absence of neurological symptoms in his lower limbs and without bladder
or bowel dysfunction. On examination he was noted to be somewhat
cachetic, neurologically intact, with an elevated white cell count and
ESR. His initial imaging is shown below:
(Above): Marked osteopenia is present. The L2/3 disc space is
ill-defined and there appears to be a crush fracture in the L3 vertebral
body.
(Above): T1-weighted sagittal MR scanning showing low signal change in
the L3 body and lower portion of the L2 vertebral body. The L2/3 disc
space is poorly defined. No epidural collection was identified on the
imaging
Initially it was felt that the changes in the L3 body were due to
metastatic prostate cancer. Because of the peridiscal changes however, a
CT-guided aspiration biopsy of the disc space was effected and tissue
taken for culture. Enterococcus was cultured from the disc space and
appropriate antibiotic therapy was commenced. A preoperative DEXA scan
gave a lumbar T score of -3.4.
After 2 weeks of antibiotic therapy, repeat MR scanning was unchanged
and the patient still suffered from severe mechanical back pain
resistant to bracing and relieve with bed rest. He again had no
neurological symptoms in his lower limbs and was neurologically intact.
It was felt that the loss of the posterior columns from his initial
surgery had left him with a grossly unstable spine that may fuse over
time with the smouldering disctis/osteomyelitis, however until that
occurred he was at major risk of developing kyphosis, collapse and
neurological compromise. Assessment by our medical and anaesthetic
services deemed him unfit for a major reconstructive procedure to
perform either an anterior or posterior vertebrectomy. In view of this,
a minimally invasive procedure was offered in hopes of maintaining a
posterior tension band whilst fusion of the anterior column occurred.
OPERATIVE DETAILS
The patient was brought to the
operating room and general anaesthesia was administered. After
administration of intravenous antibiotic, the patient was placed into
the prone position on the Jackson operating table. A digital
fluoroscope was draped into the surgical field. A 2 cm incision was
then made over the pedicle of L4 on the right. Using both AP and lateral
films, the left L4 pedicle was then cannulated using and 11G bone biopsy
needle (see below):
Under
fluoroscopic guidance, guide wires were then placed into both the L2
and L4 vertebral bodies:
The
L4 pedicle was then tapped and a 7.5 mm x 45 mm Sextant®
(Medtronic-Sofamor Danek, Memphis, TN) screw was then placed. A 6.5 mm x
50 mm screw was then placed in the L2 pedicle (see below):
 
A rod was then passed through
the heads of both screw using the Sextant® apparatus (see
below):
 
The heads were secured and a
similar procedure was performed on the left. The final construct is
shown below:
 
The entire procedure was performed through 6
incisions 2 cm in length each (see below):
There were no problems
intraoperatively and no appreciable blood loss. The patient was
transferred to the ward uneventfully. Total operating time was 70
minutes.
POSTOPERATIVE COURSE
The patient was well
postoperatively and mobilized 48 hours after surgery in a brace. His
mechanical pain had improved dramatically. His upright x-rays and CT
scans at L2 and L4 are shown below and showed no adverse features:
 
He
was discharged on oral antibiotics 2 weeks later. At last follow-up, 4
weeks after surgery, he remained pain free with no evidence of kyphosis
on imaging.
DISCUSSION
Discitis and osteomyelitis leads to loss of structural strength of the
vertebral body. With the loss of posterior elements from previous
surgery gross instability can result. In patients who would not tolerate
major spinal reconstruction, prolonged bedrest may be associated with
significant morbidity and potential mortality. In this sort of scenario,
being able to provide structural stability through a posterior tension
band can lead to eventual fusion across the involved segments. This
approach has been described before in the face of osteomyelitis, where
pedicle screw fusion alone has lead to stability and eventual fusion.1
The application of minimally-invasive technology to this however is a
new approach. By using MAST® techniques and the Sextant®
apparatus, stabilization for osteomyelitis was effected in a patient who
otherwise may not have been fit for any surgical endeavour.
The
use of minimally-invasive approaches to spinal instrumentation is an
exciting new technology that will allow surgery to be performed in
patients who previously unfit for surgical intervention. Aside from
degenerative disease, this case illustrates a novel approach to the
stabilisation of the spine in the face of serious infection in a patient
unfit for a major intervention.
REFERENCES
-
Karlsson MK, Hasserius R, Olerud C, Ohlin A: Posterior transpedicular
stabilisation of the infected spine. Arch Orthop Trauma Surg 2002
Dec;122(9-10):522-57
Case 2- Lumbar Endoscopy
History
This 55 year old man was referred to the surgeons
at Dalcross Private Hospital and after having had 3 previous lumbar
operations. The initial operation had been performed elsewhere for
lumbar disc disease, at which time he suffered an inadvertent dural
breach. Postoperatively, she developed a lumbar pseudomeningocoele
and had 2 attempts elsewhere to try and close the leak. Their was
currently no leakage of CSF from the wound. Unfortunately, he
continued to have symptoms, and had postural symptoms of worsening
back pain and pressure in the standing posture, relieved by lying
down. His most recent preoperative MRI scan on referral is shown
below (figure 2.1-2.2):
The MRI suggested a multiloculated CSF collection
in the subfascial region of the lumbar wound. In view of the fact
that he had had 2 previous attempts to repair the
pseudomeningocoele, it was felt that a further open procedure would
not be of great benefit. Symptomatically, the patient had a one-way
valve effect with fluid draining from his thecal sac into his
pseudomeningocoele, that was thought to be giving him the majority
of his symptoms.
Technique
The patient was brought to the operating room and
general anaesthesia was obtained. He was place in a prone position
on the Andrews operating table. A rigid 6 mm 30( endoscope was then
navigated into the pseudomeningocoele through a 1 cm paramedian
lumbar incision. The pinhole connection between the dura and
surrounding tissues was identified and this was enlarged with
forceps and a 4F 5 ml Fogarty balloon (see figures 2.3-2.4
below).
Figure 2.3 and 2.4 (below): The 1 mm connection
between the pseudomeningocoele and the thecal sac is identified. A
magnified view is shown to the right. Neural structures are visible
inside the dura.
Figure 2.5 (above): Post-fenestration myelogram
confirming good retrograde flow of contrast material.
The procedure was uncomplicated and an on-table
myelogram confirmed good retrograde flow between the pseudomeningocoele and the thecal sac (see figure 2.5).
Postoperatively, the patients recovery was
unremarkable and he was well at last followup from her preoperative
symptoms.
Comment
Cerebrospinal fluid leakage can complicated up to
10% of spinal surgical cases. Typically these are primary repaired
and require no further intervention. Rarely, the leaks persist and
patients may present with persistent CSF leakage from the wound, a
subcutaneous swelling or a contained but symptomatic swelling. The
initial treatment in typically aspiration and lumbar drainage or
re-exploration. An epidural blood patch may also help. Occasionally
this is unsuccessful. In the case, with 2 previous re-explorations,
it was felt a minimally invasive procedure would avoid the pain and
risks of another open procedure. Coupled with this, the internal
architecture of the pseudomeningocoele was not disturbed, which
allowed for easier identification of the flap valve.
Case 3: SpineUniverse Case Report:
Minimal Access Spinal Technologies (MAST) Fusion for Trauma
HISTORY
This 86 year old man
was admitted with a history of a fall in the absence of neurological
deficit. He had significant comorbidities in terms of cardiac and
respiratory disease. His initial imaging is shown below:
(Above): Preoperative
T2-weighted MRI scan showing edema in the T12 vertebra is consistent
with a recent fracture.
(Above): Sagittally reconstructed CT scans showing
axial fractures in the T12 vertebrae extending through all 3 columns.
The injury was consistent with a T12 undisplaced Chance fracture.
INTERVENTION
Because of his general
health, the patient was not deemed fit for a major reconstructive
procedure. Prolonged bedrest was also preferably avoided. In view of
this he was offered percutaneous pedicle screw fusion via the MAST
(Minimal Access Spinal Technology) technique using the Sextant®
apparatus (Medtronic-Sofamor Danek, Memphis, TN).
The patient is shown
below positioned in preparation for the surgery:
Using the sextant apparatus the T11 and then the
L1 pedicles were sequentially cannulated with 5.5 x 45 mm screws. 4
screws were placed with 2 rods. The procedure was performed through a
total of six 2 cm incisions. The Intraoperative imaging is shown below:
The incisions at the end of the case are shown as
below:
There were no problems intraoperatively and no
appreciable blood loss. The patient was transferred to the ward
uneventfully. Total operating time was 75 minutes.
The patient was mobilized in TLSO with no adverse
surgical complications.
4 weeks after surgery he
was transferred to the rehabilitation service with no complications as a
result of the stabilization. It would be envisioned that the
instrumentation would be removed 12 months after surgery.
DISCUSSION
This case demonstrates
the application of minimally-invasive spinal fusion technology to spinal
trauma for the stabilization of a fracture that otherwise would have
required a more extensive operation in a patient with significant
comorbidities or for whom otherwise prolonged best and immobilization
were the only options, with the risks of the known complications of
these actions present as a result.
Chance fractures are
classically described as occurring after motor vehicle accidents with
seatbelt injuries. The fractures, if through the bony elements, if
undisplaced, may be managed in a brace, but most surgeons would suggest
some form of short segment fixation with early mobilization.(1,2)
This report described
the application of MAST technology to facilitate spinal fusion for
spinal trauma. In under 90 minutes, stabilization of an unstable
fracture in a medically unwell patient was achieved. The use of this
minimally-invasive technique offers home for the management of fractures
in elderly patients as well as allowing for minimal blood loss and
operative morbidity. Clearly, not all fractures are suitably managed
through this technique but for those deemed medically inoperable or
needed simple stabilization MAST fusion offers home of rapid
mobilization with minimal risk.
REFERENCES
1. Louis CA, Gauthier
VY, Louis RP: Posterior approach with Louis plates for fractures of the
thoracolumbar and lumbar spine with and without neurologic deficits.
Spine 23: 2030-2039, 1998
2. Parker JW, Lane J,
Karaikovic EE, et al: Successful short-segment instrumentation and
fusion for thoracolumbar spine fractures. A Consecutive 4 ½ year series.
Spine 25: 1157-1169, 2000
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