Добавил:
Sekretar
kiopkiopkiop18@yandex.ru
t.me/Prokururor I Вовсе не секретарь, но почту проверяю
Опубликованный материал нарушает ваши авторские права? Сообщите нам.
Вуз:
Предмет:
Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_6013_Библиотеки_им_академика_М_И_Перельмана.pdf
Procedure 27 | Lateral Extracavitary Approach for Vertebrectomy 269
P O S T OP E R AT IV E P E A R L S
• Patients should be mobilized fairly
quickly.
• If patients are not rapidly mobilized,
they should be on prophylaxis for deep
venous thrombi.
P O S T OP E R AT IV E P I T F A L L S
• When removing surgical drains or
epidural pain catheters, care must be
taken to ensure that no part of the
catheter is retained in the body.
Postoperative Care and Expected Outcomes
n
Most patients are kept intubated in the intensive care unit for the first night
after surgery because of increased facial swelling.
n
Patients are mobilized in an orthosis, usually by postoperative day 2, and they
are evaluated by a physical therapist.
n
Surgical drains are also usually removed by the second postoperative day.
n
Upright films are obtained.
n
Patients may require patient-controlled analgesia devices.
n
Patients are ready for discharge by the third to fifth postoperative day.
n
The most common complications include pneumothorax, pleural effusions, pneu-
monia, wound infections, and cerebrospinal fluid leaks.
Evidence
Alexander GL. Neurological complications of spinal tuberculosis. Proc R Soc Med
1946;39:730-4.
Bohlman HH, Eismont FJ. Surgical techniques of anterior decompression and
fusion for spinal cord injuries. Clin Orthop 1981;154:57-67.
Capener N. The evolution of lateral rhachotomy. J Bone Joint Surg Br 1954;36:
173-9.
Clark WK. Spinal cord decompression in spinal cord injury. Clin Orthop 1981;154:
9-13.
Erickson DL, Leider LL, Brown WE. One-stage decompression-stabilization for
thoracolumbar fractures. Spine 1977;2:53-6.
Larson SJ. Unstable thoracic fractures: treatment alternatives and the role of the
neurosurgeon. Clin Neurosurg 1980;27:624-40.
Larson SJ, Holst RA, Hemmy DC, et al. Lateral extracavitary approach to traumatic
lesions of the thoracic and lumbar spine. J Neurosurg 1976;45:628-37.
Morgan TH, Wharton GW, Austin GN, et al. The results of laminectomy in patients
with incomplete spinal cord injuries. Paraplegia 1970;9:14-21.
Schneider RC. Surgical indications and contraindications in spine and spinal cord
trauma. Clin Neurosurg 1962;8:157-84.
Wagner FC Jr, Chehrazi B. Spinal cord injury: indications for operative
intervention. Surg Clin North Am 1980;60:1049-54.
P R O C ED U R E 2 8
Osteotomy Techniques
(Smith-Petersen and Pedicle
Subtraction) for Fixed
Sagittal Imbalance
Lukas P. Zebala, Michael P. Kelly, and Keith H. Bridwell
I N D I CAT I O NS P I T F A L L S
• Smith-Petersen osteotomies can lead to
coronal imbalance, pitching the patient
toward the concavity.
• Inadequate facetectomies can cause
nerve root impingement with deformity
correction through the SPO.
• Smith-Peterson osteotomies require a
mobile disk space to allow correction
by closing down the middle and
posterior columns and opening up the
anterior column.
• Pedicle subtraction osteotomies can
lead to neurologic deficits (usually
single nerve root injury), subluxations,
and substantial intraoperative blood
loss.
• Pedicle subtraction osteotomy
performed below L3 or through prior
laminectomy sites carry a greater risk of
a neurologic deficit.
• Pseudarthrosis may develop cranial
or caudal to a PSO, with normal or
only slightly degenerated cranial
intervertebral disks above or below the
PSO site.
Indications
n
Fixed sagittal imbalance.
n
Type I and type II sagittal imbalances: Type I imbalance is segmental, where a
portion of the spine is in a hypolordotic or kyphotic position, but overall balance
is satisfactory (C7 plumb falls through or within 2 cm anterior to the sacrum),
compensated by hyperextension of cranial and caudal segments. A type II
imbalance occurs when the patient cannot compensate because segments
above or below the kyphotic or hypolordotic spine are substantially degenerated
and, therein, they are not able to hyper extend and maintain balance.
n
Smooth and angular kyphosis.
n
Combined coronal and sagittal imbalance.
n
Smith-Petersen osteotomies (SPO) or Ponte osteotomy are reserved for smaller
sagittal deformities that are long, smooth, and rounded (Figure 28-1, A and B).
They can be safely performed in the thoracic and lumbar spine. No retraction of
the thecal sac is needed.
n
A pedicle subtraction osteotomy (PSO) is indicated in sharp, angular deformities
and for a more marked sagittal imbalance (greater than 10 cm positive) (Figure
28-2, A and B). They are best performed at L2 or L3, which allows for an
adequate number of fixation points above and below the osteotomy. A PSO
performed below L3 offers more sagittal correction but has reduced distal fixation points. A PSO can be performed in the thoracic spine, but a costotransversectomy approach is then needed, because the thecal sac should not be retracted
in cord territory. An asymmetric pedicle subtraction osteotomy can be used to
correct a combined coronal and sagittal imbalance.
I N D I CAT I O NS
C O N T RO V E R S IE S
• For most fixed sagittal and coronal
deformities, the options are either
multiple Smith-Petersen osteotomies or
one pedicle subtraction procedure.
• A Smith-Petersen osteotomy is
performed through ankylosed spinal
segments. A Ponte osteotomy is exactly
the same as an SPO except through
unfused spine segments. Commonly,
the osteotomy is simply referred to as
an SPO, whether done through fused
or unfused spine segments.
Examination/Imaging
n
Assessment of the patient’s overall coronal and sagittal balance, both clinically
and radiographically, is important (Figures 28-1, A and B, and 28-2, A and B).
n
Long-cassette (36 inch), standing anteroposterior (AP) and lateral radiographs
(preferably with the patient’s knees fully extended) are obtained preoperatively.
n
For sagittal plane deformity, comparison of standing AP and lateral radiographs
to prone and/or supine fulcrum-hyperextension long-cassette radiographs will
help assess deformity flexibility.
n
For patients with prior spinal fusions, oblique AP and lateral radiographs and
computed tomography (CT) scans help determine if there is a pseudarthrosis
from prior surgery.
n
Magnetic resonance imaging (MRI) and CT myelogram are obtained to investi-
gate areas of spinal stenosis.
Procedure 28 | Osteotomy Techniques (Smith-Petersen and Pedicle Subtraction) for Fixed Sagittal Imbalance 271
1-7-00
31+2
Preop
Postop
6-27-05
36+7
4+11 yr po
A
Postop
6-27-05
36+7
98°
Preop
1-7-00
31+2
4+11 yr po
B
FIGURE 28-1, A-B
272 Procedure 28 | Osteotomy Techniques (Smith-Petersen and Pedicle Subtraction) for Fixed Sagittal Imbalance
FIGURE 28-2, A-B
Procedure 28 | Osteotomy Techniques (Smith-Petersen and Pedicle Subtraction) for Fixed Sagittal Imbalance 273
Smith-Petersen Osteotomy
Preop
Area of bony resection
FIGURE 28-3
T R E A T M E N T OP T I O N S
• Either multiple Smith-Petersen
osteotomies or one pedicle subtraction
procedure for fixed sagittal imbalance
can be used. Often for smooth kyphosis
or mild sagittal imbalance (5 to 10 cm
positive) multiple SPOs through the
apex are adequate to correct the
deformity. For angular kyphosis or
substantial sagittal imbalance (greater
than 10 cm), a single lumbar PSO may
be adequate. In general, the degree of
kyphotic correction with a single SPO is
10 degrees/level or 1 degree/mm bone
resected. On average, 30 to 40 degrees
of sagittal plane correction can be
achieved with a lumbar PSO, and less
(≈25 degrees) with a thoracic PSO.
• If the fixed sagittal deformity is
associated with a coronal deformity,
such that shortening of the convex side
will rebalance the patient, options are
either multiple asymmetric SmithPetersen osteotomies or one
asymmetric pedicle subtraction
procedure (see Figure 28-2, A and B).
Postop
Surgical Anatomy
n
Smith-Petersen osteotomy involves creating a chevron trough in the posterior
elements by resecting the posterior elements through the facet joints and pars
interarticularis and posterior ligaments (supraspinous, intraspinous, and ligamentum flavum). A mobile disk space allows closure of the middle and posterior
columns and spontaneous opening of the anterior column. (Figure 28-3).
n
A pedicle subtraction osteotomy requires resection of the posterior elements
and pedicles and decancellation of the vertebral body in a V-shaped fashion
through the transpedicular corridor. With osteotomy closure, a large cancellous
bone contact area is present as the posterior and middle columns are closed
and the osteotomy hinges on the anterior vertebral body. More aggressive
resections include the disk space above the decancellated segment, which may
lead to a greater sagittal plane correction (Figure 28-4).
274 Procedure 28 | Osteotomy Techniques (Smith-Petersen and Pedicle Subtraction) for Fixed Sagittal Imbalance
Three-Column Pedicle Subtraction Osteotomy
Preop
Area of bony resection
FIGURE 28-4
P O S I TI O N I N G PE A R L S
• Use Jackson table with six posts, which
allows the abdomen to hang free.
• Both osteotomies should be done
with the use of intraoperative
neuromonitoring.
P O S I TI O N I N G PI T FA L L S
• Positioning of the anterior chest and
abdominal pads is critical. If the pads
compress the abdomen, more epidural
bleeding can be expected.
• It is best to position the patient’s lower
extremities so that the nursing team
can access them to facilitate closure of
the osteotomies.
Postop
Positioning
n
The patient is prone for both procedures, with the abdomen free in order to
decrease intraabdominal pressure and epidural bleeding.
n
If the sagittal deformity is marked and fixed, position the patient with some
flexion of the hips and knees. Closure of the osteotomies is facilitated by extending the hips under the drapes.
n
Use of an intraoperative halo or Gardner-Wells traction allows the face and eyes
to be free during these lengthy procedures.
n
Arms are maintained on well-padded arm boards in a 90-degree–to–90-degree
position, with attention given to avoid shoulder hyperextension.
Procedure 28 | Osteotomy Techniques (Smith-Petersen and Pedicle Subtraction) for Fixed Sagittal Imbalance 275
FIGURE 28-5
S T E P 1 P EA R L S
• Fixation points can be placed before or
after the osteotomies are performed.
• For large deformities or abnormal
pedicle anatomy, performing a
Smith-Petersen osteotomy first, before
pedicle screw placement, can help
identify the medial and superior borders
of the pedicle, to assist in locating the
starting point and cannulation of the
pedicle tract.
S T E P 2 P EA R L S
• With Smith-Petersen osteotomies, it
is advisable to undercut as much
as possible and to remove all the
ligamentum flavum.
FIGURE 28-6
Procedure A: Smith-Petersen Osteotomy
Step 1
n
Identify the pedicles at all levels where Smith-Petersen osteotomies are planned
by placing pedicle screws (Figure 28-5).
Step 2
n
Remove the interspinous ligaments down to level of the ligamentum flavum,
and identify the median raphe. Ensure adequate space between the ligamentum
flavum and dura with a Woodson elevator, and use Kerrison punches to resect
a V of bone that starts centrally and works out laterally through the facet joints
and pars (Figure 28-6).
276 Procedure 28 | Osteotomy Techniques (Smith-Petersen and Pedicle Subtraction) for Fixed Sagittal Imbalance
Step 3
n
Close the osteotomies by a combination of compression and cantilevering
(Figure 28-7).
Procedure B: Pedicle Subtraction Osteotomy
Step 1
n
Resect all the posterior elements around the pedicles with a combination of
Leksell rongeurs, a high-speed burr, and Kerrison punches (Figure 28-8).
Step 2
n
Decancellate the pedicles and the vertebral body (Figure 28-9).
Step 3
n
The dorsal vertebral cortex is imploded into the vertebral body cavity with a
Woodson elevator or reverse angled curette. The dorsal vertebral cortex must
be thin to perform this step safely (Figure 28-10).
Step 4
n
Resect the lateral vertebral cortex with a Leksell rongeur bilaterally (Figure
28-11).
FIGURE 28-7
Step 5
n
Close the osteotomy by compression/cantilever/extension of chest and lower
extremities (Figure 28-12).
FIGURE 28-8
FIGURE 28-9
Procedure 28 | Osteotomy Techniques (Smith-Petersen and Pedicle Subtraction) for Fixed Sagittal Imbalance 277
S T E P 1
I N S T RU M E N T A T I O N /
I M P L AN TAT IO N
• Instrumentation should extend the
entire length of the fusion area.
S T E P 2 P EA R L S
• It is important to resect a symmetric
wedge of bone within the vertebral
body to minimize the potential for
coronal decompensation with
osteotomy closure.
S T E P 3 P IT FA L L S
• Attempting to greenstick the posterior
vertebral cortex that is too thick may
require too much force and increases
the risk of a ventral dural tear.
FIGURE 28-10
S T E P 3 P EA R L S
• Remember, that as osteotomies are
closed, the contour in the rods will
have to change. As more closure is
achieved, more lordosis is needed in the
rods.
• If possible, limit the amount of force
placed on the pedicle screws and apply
force more through the posterior
elements.
FIGURE 28-11
FIGURE 28-12
278 Procedure 28 | Osteotomy Techniques (Smith-Petersen and Pedicle Subtraction) for Fixed Sagittal Imbalance
A
FIGURE 28-13, A-B
S T E P 3
I N S T RU M E N T A T I O N /
I M P L AN TAT IO N
• Instrumentation should extend the
entire length of the fusion area.
S T E P 1 P EA R L S
• Fixation points should be placed before
the osteotomy is performed.
S T E P 5 P EA R L S
• Remember, that as the osteotomy is
closed, the contour in the rods will
have to change. As more closure is
achieved, more lordosis is needed in the
rods.
• If possible, limit the amount of force
placed on the pedicle screws and apply
force more through the posterior
elements.
S T E P 5 P IT FA L L S
• With pedicle subtraction procedures,
there is some risk of dural buckling and
the posterior elements imploding on
the dura. The authors’ preference is to
enlarge the field centrally to observe
dural buckling (Figure 28-13) and to
“feel” the dorsal canal with nerve
hooks/Woodson elevators.
• Watch carefully for subluxation.
B
Postoperative Care and Expected Outcomes
n
Most patients should show 20% to 30% improvement in SRS-30 and Oswestry
Quality of Life (QOL) scores at 2- and 5-year follow-up, as in the authors’
publications.
n
Stand the patient in the morning after surgery and have the patient walk in
place.
n
The patient should be able to walk 3 miles per day by 2 months
postoperatively.
n
Avoid flexion and axial loading of the spine for at least 4 months
postoperatively.
n
No cast or brace should be needed.
n
The patient should be off all pain medicines by 2 months postoperatively.
n
Use no nonsteroidal antiinflammatory drugs (NSAIDs) for 6 months
postoperatively.
Evidence
Berven SH, Deviren V, Smith JA, et al. Management of fixed sagittal plane
deformity: results of the transpedicular wedge resection osteotomy. Spine
2001;26:2036-43.
Substantial correction can be obtained by performing a pedicle subtraction
osteotomy. The procedure is not risk-free.
Bridwell KH. Decision making regarding Smith-Petersen vs. pedicle subtraction
osteotomy vs. vertebral column resection for spinal deformity. Spine
2006;31(19):S171-8.
Smith-Petersen osteotomies are most helpful for long-sweeping thoracic
kyphotic deformities and mild to moderate sagittal imbalances. Pedicle
subtraction osteotomies are most helpful for major sagittal imbalances, sharp
angular lumbar kyphosis, and coexistent type 1 coronal imbalances.
Bridwell KH, Lewis SJ, Edwards C, et al. Complications and outcomes of pedicle
subtraction osteotomies for fixed sagittal imbalance. Spine 2003;28:2093-101.
Substantial complications associated with pedicle subtraction osteotomies
include neurologic deficit, substantial blood loss, and adding on to the sagittal
deformity if the entire thoracic and lumbar spine is not fused.