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Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_6013_Библиотеки_им_академика_М_И_Перельмана.pdf
P R O C ED U R E E P I TF A L L S
• Iliac screws require an additional
incision for placement.
• The procedure may decrease the
volume of autogenous bone graft.
• The procedure requires cumbersome
offset connectors (Figure 25-17).
• The procedure may cause pain because
of prominence.
• The procedure requires removal in 22%
of the patients (Tsuchiya et al, 2006).
Procedure 25 | Sacropelvic Fixation 249
n
Technique
• The starting point is slightly anterior to the PSIS. Figure 25-15 shows the
intraoperative starting point of iliac screws over the posterior superior iliac
spine.
• Two trajectories can then be taken for the screw direction. One trajectory is
directed toward the superior portion of the acetabulum (Figure 25-16,
A
). Another path is directed toward the AIIS (Figure 25-16,
Path B
). The latter
is preferred, because there is a lower risk for violation of the acetabulum and
longer screws can be used. The trajectory is 25 degrees lateral and 30 degrees
caudal. Fluoroscopy can be helpful in placement of iliac screws.
• The screw length is typically at least 80 mm, with a diameter of 7 to 8 mm.
Path
FIGURE 25-15
FIGURE 25-16
FIGURE 25-17
Path B
Path A
250 Procedure 25 | Sacropelvic Fixation
FIGURE 25-18
P R O C ED U R E F P E AR L S
• Partially burying the S1 screws allows
ease of insertion of the bar into the
iliac crest.
• Adding a gentle bend to the bar avoids
impingement on the spinal canal.
P R O C ED U R E F P I TF A L L S
• Sacral insufficiency fractures develop
in osteoporotic patients. The mode
of failure appears to be a shear/
compression fracture at or below the
S1 pedicle screws.
• Connectors can be cumbersome to
place.
• There is a high rate of implant removal
secondary to pain.
Procedure F: Transilial Bar
n
In the 1960s, Harrington devised a sacral bar. At that time fixation to the bar
was by hooks only, which did not control rotational stresses or flexion extension
as well. Kostuik (1988) subsequently modified the Harrington sacral bar moments
by using a transiliac bar fixed to S1 pedicle screws, to which proximal longitudinal members could be connected (Figure 25-18). Sacropelvic fixation using
the transilial bar technique is an easy and effective method of achieving pelvic
anchorage in long posterior spinal fusions but is not recommended without the
use of anterior column support.
n
Technique
• The starting point is 1 to 2 cm anterior to both the posterior superior iliac
spines.
• Regarding direction, the transilial bar is inserted in a retrograde fashion
(inside–out method) to one iliac wing, then passed through both tables of
the other iliac wing in a similar fashion. The bar is then attached to the S1
pedicle screws and subsequently attached to the rest of the construct.
Procedure G: S2 Alar Iliac Screws (S2AI)
n
Pelvic fixation using the S2 alar iliac technique was described by Kebaish (2010)
and by Sponseller and colleagues (2010) in the adult and pediatric populations,
respectively. Use of the S2 alar iliac technique may address some of the issues
with spinopelvic fixation. S2AI screws do not require a separate fascial or skin
incision or the use of offset connectors. Placement of S2AI screws does not
interfere with iliac crest harvest, while allowing the use of longer screws than
the iliac bolts allow. The solid pelvic anchor provided by the S2AI technique
allows performing corrective procedures at the lumbosacral junction, such as S1
and L5 osteotomies, thus achieving more linear correction of the sagittal vertical
axis, and hence better sagittal restoration of sagittal balance.
n
Technique (authors’ preference)
• The starting point is midway between the first and second sacral foramina
(Figures 25-19 and 25-20).
• Screw direction
◆
The trajectory is aimed lateral, approximately 40 degrees to the horizontal
plane and 20 to 30 degrees caudal, depending on the pelvic tilt. Figure
25-21 is a schematic representation of the S2AI screw direction in differ-
ent planes—transverse (Figure 25-21, A), coronal (Figure 25-21, B), and
sagittal plane (Figure 25-21, C ).
FIGURE 25-19
Procedure 25 | Sacropelvic Fixation 251
X X
FIGURE 25-20
A
C
FIGURE 25-21, A-C
B
252 Procedure 25 | Sacropelvic Fixation
P R O C ED U R E G P E AR L S
• Insertion of S1 screws first will ensure a
starting point that allows in-line rod
placement.
• Using the greater trochanter as a
landmark allows safe placement
without fluoroscopy in most patients.
Figure 25-22 is an intraoperative view
showing the direction of drilling of
the S2AI screw toward the greater
trochanter, which may be felt by the
surgeon’s opposite hand.
• Tap drilling and ensuring there is a hard
end point during advancement of the
drill will prevent violation of the cortices
of the ilium.
• Placing a guidewire after the initial
drilling could minimize the use of
a C-arm and guarantee a correct
trajectory.
• A teardrop view will guarantee a
correct trajectory in difficult pelvic
anatomy (Figure 25-23, A).
• Keeping the screw pathway just above
the greater sciatic notch allows the
biggest screw diameter (Figure 25-23,
B)
• Partially burying the screw head to
avoid prominence allows, on average,
15-mm deeper implants than with iliac
screws.
• S2AI screws can be placed
percutaneously by a minimally invasive
approach (Figure 25-24).
•
Figure 25-25 shows postoperative
radiography of double S2AI screws.
FIGURE 25-22
◆
Fluoroscopy is helpful but not always necessary; an anteroposterior view
showing the pelvis and the sciatic notch is most beneficial.
◆
The path of the drill should be within 20 mm proximal to the greater sciatic
notch and aimed toward the AIIS.
◆
A 2.5-mm drill is used initially through the sacral ala, and once the SI joint
is crossed, a 3.2-mm drill is used to guard against breakage.
◆
A teardrop C-arm view, at this stage, helps ensure the anteroposterior
trajectory within the thickest part of the ilium, without cortical breach.
n
A polyaxial screw of an average 80 to 100 mm is used; the diameter is usually
8 to 10 mm, but never less than 8 mm to avoid screw breakage.
Procedure 25 | Sacropelvic Fixation 253
A
FIGURE 25-23, A-B
P R O C ED U R E G P I TF A L L S
• Lateral cortical penetration is the most
common misplacement.
• There appears to be no significant
effect on the SI joint at 2 years;
however, the long-term effect of
violating the SI joint is unknown, and
longer follow up may be needed.
B
FIGURE 25-24
FIGURE 25-25
254 Procedure 25 | Sacropelvic Fixation
P O S T OP E R AT IV E P E A R L S
• Wound suction drains should be used.
• External immobilization is usually not
required, because the rigidity of the
fixation allows early patient ambulation.
Postoperative Care and Expected Outcomes
Complications of Pelvic Fixation
n
Misplacement and injuries to adjacent structures
• Injuries to structures in the sciatic notch, including the superior gluteal artery
and the sciatic nerve, are rare.
• This complication can be avoided by paying close attention to the anatomy
of the pelvis and using external bony landmarks. Some clinicians advocate
placing a finger or a blunt instrument in the notch, although doing so would
require additional dissection.
• Fluoroscopy can also be very helpful, especially in patients with unusual
anatomy, and until the surgeon becomes more experienced with the
procedure.
• Maintenance of a bony end point and the correct measurement, and choice
of the screw size, will avoid medial or lateral cortical violation.
n
Implant prominence and loosening
• Implant prominence is a major challenge in small patients and in those with
compromised soft tissues, as is the case with children with neuromuscular
deformities.
• Loosening continues to be a problem with the Galveston technique but
appears to be less common with S2AI and iliac screws. It may not cause
symptoms, especially if the fusion is already complete.
n
Wound complications and infection
• Techniques requiring extensive surgical exposure are associated with a higher
risk of wound complications, including infection.
• One study (Tsuchiya et al, 2006) of 81 patients treated with iliac screw fixation reported a 4% infection rate.
• A recent study (Sponseller et al, 2010) found no wound infection in 27 children who underwent pelvic fusion with the sacral alar iliac technique. This
finding may have been related to the minimum dissection needed with this
procedure, which preserved the soft tissue envelope.
n
Nonunion and implants failure
• If fusion does not happen in a timely manner, fixation failure is destined to
occur, possibly from implant breakage or loosening.
• These two problems often occur together; no matter how strong the fixation
is, the patient’s biology plays a role in achieving a solid fusion.
Procedure 25 | Sacropelvic Fixation 255
Evidence
Allen BL Jr, Ferguson RL. The Galveston technique for L rod instrumentation of
the scoliotic spine. Spine 1982;7:276-84.
Berry JL, Stahurski T, Asher MA. Morphometry of the supra sciatic notch intrailiac
implant anchor passage. Spine 2001;26:E143-8.
Bridwell KH, Edwards CC, Lenke LG. The pros and cons to saving the L5–S1 motion
segment in a long scoliosis fusion construct. Spine 2003;20:234-42.
Devlin VJ, Asher MA. Biomechanics and surgical principles of long fusions to the
sacrum. Spine State Art Rev 1996;10:515-44.
Farcy JP, Rawlins BA, Glassman SD. Technique and results of fixation to the sacrum
with iliosacral screws. Spine 1992;17(Suppl. 6):S190-5.
Glazer PA, Colliou O, Lotz JC, et al. Biomechanical analysis of lumbosacral fixation.
Spine 1996;21:1211-22.
Gokaslan ZL, Romsdahl MM, Kroll SS, et al: Total sacrectomy and Galveston
L-rod reconstruction for malignant neoplasms. Technical note. J Neurosurg
1997;87:781-7.
Harrington PR. Treatment of scoliosis: correction and internal fixation by spine
instrumentation. J Bone Joint Surg Am 1962;44:591-610.
Kebaish, KM. Sacropelvic fixation techniques and complications. Spine
2010;35:2245-51.
Kim YJ, Bridwell KH, Lenke LG, Rhim S, Cheh G. Pseudarthrosis in long adult
spinal deformity instrumentation and fusion to the sacrum: prevalence and risk
factor analysis of 144 cases. Spine 2006;20:2329-36.
Kostuik JP. Treatment of scoliosis in the adult thoracolumbar spine with special
reference to fusion to the sacrum. Orthop Clin North Am 1988;19:371-81.
Kostuik JP, Musha Y. Extension to the sacrum of previous adolescent scoliosis
fusions in adult life. Clin Orthop 1999;364:53-60.
Lebwohl NH, Cunningham BW, Dmitriev A, et al. Biomechanical comparison of
lumbosacral fixation techniques in a calf spine model. Spine 2002;27:2312-20.
Lehman RA Jr, Kuklo TR, Belmont PJ Jr, et al. Advantage of pedicle screw fixation
directed into the apex of the sacral promontory over bicortical fixation:
a biomechanical analysis. Spine (Phila Pa 1976) 2002;27:806-11.
Lemma M, Cohen DB, Riley LH 3rd, et al. Fusion to the sacrum: results of transiliac
fixation. Spine J 2002;2:3S-44.
McCord DH, Cunningham BW, Shono Y, et al. Biomechanical analysis of
lumbosacral fixation. Spine (Phila Pa 1976) 1992;17:S235-43.
Moshirfar A, Rand FF, Sponseller PD, et al. Pelvic fixation in spine surgery.
Historical overview, indications, biomechanical relevance, and current
techniques. J Bone Joint Surg Am 2005;2(Suppl. 87):89-106.
O’Brien JR, Matteini L, Yu WD, Kebaish KM. Feasibility of minimally invasive
sacropelvic fixation percutaneous S2 alar iliac fixation. Spine (Phila Pa 1976)
2010;35:460-4.
O’Brien, MF, Kuklo TR, Lenke LG. Sacropelvic instrumentation: anatomic and
biomechanical zones of fixation. Semin Spine Surg 2004;16:76-90.
Ogilvie JW, Schendel M. Comparison of lumbosacral fixation devices. Clin Orthop
Relat Res 1986;203:120-5.
Peelle MW, Lenke LG, Bridwell KH. Comparison of pelvic fixation techniques in
neuromuscular spinal deformity correction: Galveston rod versus iliac and
lumbosacral screws. Spine 2006;31:2392-8.
Ruland CM, McAfee PC, Warden KE, Cunningham BW. Triangulation of pedicular
instrumentation: a biomechanical analysis. Spine 1991;16:S270-6.
Santos ERG, Rosner MK, Perra JH, Polly DW. Spinopelvic fixation in deformity: a
review. Neurosurg Clin N Am 2007;18:373-84.
Schildhauer TA, McCulloch P, Chapman JR, Mann FA. Anatomic and radiographic
considerations for placement of transiliac screws in lumbopelvic fixations.
J Spinal Disord Tech 2002;15:199-205.
Shirado O, Zdeblick TA, McAfee PC, et al. Biomechanical evaluation of methods of
posterior stabilization of the spine and posterior lumbar interbody arthrodesis
for lumbosacral isthmic spondylolisthesis. J Bone Joint Surg Am 1991;73:518-26.
Smith SA, Abibto JJ, Carlson GD, Anderson DR, Taggart KW. The effects of depth
of penetration, screw orientation, and bone density on sacral screw fixation.
Spine 1993;18:1006-10.
Sponseller PD, Zimmerman RM, Ko PS, et al. Low profile pelvic fixation with
the sacral alar iliac technique in the pediatric population improves results
at two-year minimum follow-up. Spine (Phila Pa 1976) 2010;35:1887-92.
Tsuchiya K, Bridwell KH, Kuklo TR, et al. Minimum 5-year analysis of L5–S1 fusion
using sacropelvic fixation (bilateral S1 and iliac screws) for spinal deformity.
Spine (Phila Pa 1976) 2006;31:303-8.
P R O C ED U R E 2 6
Posterior Far Lateral
Disk Herniation
Chadi Tannoury, D. Greg Anderson, Alexander R. Vaccaro,
and Todd J. Albert
I N D I CAT I O NS P I T F A L L S
• Diagnostic process is complex.
• Clinical symptoms alone, without
radiographic studies, do not
differentiate this type of disk hernia
from other entities.
• Radiographic findings may have no
clinical correlation, and/or false-positive
results may be derived from imaging
studies.
I N D I CAT I O NS
C O N T RO V E R S IE S
• A far lateral disk herniation (FLDH)
associated with adjacent canal stenosis
at the level above
• Monoradicular symptoms (denoting
isolated far lateral disk herniation)
versus multiradicular symptoms
(denoting a far lateral disk associated
with medially located pathologies,
including degenerative changes, canal
stenosis, or central disk herniations)
Indications
n
Intractable radiculopathy resistant to conservative measures
n
Unilateral, single-level, nerve root compression lateral to the neuroforamen
n
Far lateral disk herniation confirmed by computed tomography (CT) scan or
magnetic resonance imaging (MRI): nucleus pulposus herniates beyond the
intervertebral foramen, or at least two-thirds lateral to the vertebral pedicle
(Papavero and Caspar, 1993).
n
Absence of segmental instability, facet incompetence, or additional pathologies,
that is, spinal stenosis or associated central disk herniation
n
Radiculopathy correlating with radiographic evidence of far lateral disk hernia-
tion (FLDH) compressing the symptomatic exiting nerve root
Examination/Imaging
n
Presentation
• Occurs most often in patients greater than 40 years of age
• Slight male predominance
• Most commonly affects upper lumbar roots (e.g., anterior thigh pain) although
can affect any level
• Exiting nerve root affected rather than traversing nerve root
• Lower limb pain predominates over low back pain
• Pain referred to the knee can be mistaken for primary hip or knee
pathology.
n
Physical examination
• Limitation of flexion/extension, lumbar list, antalgic gait
• Neurologic signs (sensory, motor, or both); L2 = groin/medial thigh; L3 =
anterior thigh; L4 = anterolateral thigh/medial leg; L5 = dorsal foot
• Diminished or absent deep tendon reflex
• Reproduction of symptoms by lateral bending to the side of the lesion
• Positive nerve tension tests: femoral nerve stretch and the Lasegue sign
(depending on level of herniation)
• Muscular atrophy
• Paravertebral point tenderness (intertransverse membrane level)
• Bowel/bladder dysfunction is not typically present.
Procedure 26 | Posterior Far Lateral Disk Herniation 257
A B C
FIGURE 26-1
T R E A T M E N T OP T I O N S
• Conservative management
• Local spinal infiltration (anesthetics,
corticosteroids, etc.) with or without
fluoroscopic guidance
• Surgical
• SPORT study showed beneficial effect
of surgery at each follow-up period
(Pearson et al, 2008).
• Midline interlaminar approach
• Intertransverse transmuscular
• Intertransverse muscle-splitting
• Transforaminal percutaneous
(partial/complete facetectomy, or
removal of the pars interarticularis)
(Figure 26-1, arrow A)
approach (Figure 26-1, arrow B)
approach (Figure 26-1, arrow C )
approach
A
n
Imaging
B
C
• Plain radiographs: mainly to rule out other disorders (spondylolysis/listhesis,
lumbar stenosis, etc.)
• MRI is the method of choice (most sensitive diagnostic tool); however, one
third of FLDH cases may be overlooked (Osborn et al, 1988). Seventy-five
percent of FLDH cases occur at L4-5 and above (O’Hara and Marshall, 1997),
with 46% occurring at L2-3 and L3-4 levels.
• Most accurate diagnosis offered by CT diskography (Jackson and Glah, 1987)
• Radiologic findings supporting the diagnosis of FLDH include
◆
Disk fragment lateral to the neural foramen
◆
Absence of foraminal or paraforaminal fat around nerve root
258 Procedure 26 | Posterior Far Lateral Disk Herniation
L3 vertebra
L4 vertebra
A
B
FIGURE 26-2
L3
FIGURE 26-3
L4
Surgical Anatomy
n
Anatomic definition: Far lateral, extraforaminal, or extreme lateral disk hernia-
tion denotes a disk hernia occurring lateral to the neuroforamen and the facet
joint complex (Figure 26-2). The herniated disk fragment usually compresses the
exiting nerve root and displaces it superiorly and laterally under tension.
n
Because of its anatomic location (Figure 26-3, A), unlike the posterolateral
herniated nucleus pulposus (HNP), which affects the traversing nerve root
(Figure 26-3, B), FLDH affects the exiting nerve root at the same level.
n
The anatomic boundaries of the “operative window” or “surgical corridor” for
the intertransverse lateral approach (Figure 26-4) are
• Superiorly: the lower edge of the pedicle and the superior transverse process
• Medially: the pars interarticularis
• Inferiorly: the facet joint and superior border of the inferior transverse process
FIGURE 26-4