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Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_6019_Библиотеки_им_академика_М_И_Перельмана.pdf
246
R.F. Heary and J.C. Quinn
Fig. 20.3 Case example preoperative imaging. A lateral
radiograph (a) and sagittal (b) and axial MR of the L4–L5
(c) and L5–S1 (d) disc space demonstrate an L4–L5
cages, and in the lateral gutters is ideal for
achieving stable arthrodesis.
• A variety of interbody cages of different
design made of different materials have been
developed. Some options include titanium
mesh cages, wedged structural allograft,
threaded cylindrical cages, banana-shaped
cages, and straight cages.
• Straight cages are typically inserted in an
oblique fashion. Lordosis restoration using
straight cages relies the anterior height of the
cage being larger than the posterior height.
degenerative spondylolisthesis with significant bilateral
foraminal stenosis at L4–L5 and L5–S1
Use of banana cages with a rotatable inserter
allows for the ability to “steer” the implant
into a horizontal position along the anterior
portion of the disc space. With posterior
compression the cage acts as a fulcrum and
allows for a greater degree of segmental
lordosis.
• Careful, meticulous end plate preparation is
critical to achieve interspace fusion. Avoid
violation of end plate during discectomy to
prevent graft subsidence which may lead to
loss of indirect decompression.
20 Transforaminal Lumbar Interbody Fusion
247
Fig. 20.4 Case example postoperative imaging.
Postoperative AP (a) and lateral (b) radiographs following
L4–L5 and L5–S1 TLIFs. Complete posterior column
osteotomies were performed at each level; discectomy
and cage placement were performed from the right side at
Complications and Strategies for Avoidance
TLIF has been shown to be a safe and effective
technique for lumbar spine fusion. Complication
rates for single-level TLIF are relatively low with
fusion rates of greater than 90% for single-level
procedures. Rates of transient neurological deficit
in the range of 2–7% have been reported [16–18].
Care should be taken to identify and protect all
neural structures during discectomy and interbody placement to avoid inadvertent injury.
Following interbody grafting the neural foramen
should be palpated with blunt probe to ensure
there is no residual compression of the exiting
nerve. There have been reports of the development of contralateral radicular pain symptoms
following unilateral TLIF. It is hypothesized that
with compression and lordosis correction, there is
risk for increased foraminal stenosis when a facetectomy is not completed. Care must be taken to
evaluate both foramen on the preoperative MRI
regardless of which side the symptoms are on.
both levels. Titanium cages were placed into the anterior
third of the disc spaces at each level followed by compression across these segments allowing for a restoration of
segmental lordosis across the L4–S1 segments
Hardware complications from misplaced ped-
icle screws are relatively rare with an incidence
of less than 5% in most studies. Cage migration
rates have been reported as high as 8% without
posterior instrumentation. This is a rare complication with the additional stabilization afforded
by segmental pedicle screw instrumentation,
which allows for compression across the interspace after graft placement. Appropriate sizing of
interbody graft, preservation of the anterior annulus, and proper placement within the anterior 1/3
of the interspace graft migration are important in
limiting the rates of graft migration. Graft subsidence may occur and result in loss of correction,
loss of indirect decompression, and hardware
failure. Factors predisposing to subsidence
include inadequate graft technique, sizing, end
plate violation during discectomy, and patient
factors such as osteoporosis. Biomechanical
load-sharing properties of the interbody graft are
predicated on the bony stability of intact end
plates. Fracture or violation of the end plate during the procedure may result in subsidence. To
minimize this risk, particular care must be taken
248
R.F. Heary and J.C. Quinn
to appreciate the sagittal orientation of the end
plates with intraoperative imaging and to maintain the trajectory of the instruments parallel to
this orientation.
Vascular injury during TLIF, though rare, is a
potentially catastrophic complication that all surgeons must be aware of. Violation of the anterior
annulus may result in inadvertent entry into the
retroperitoneum with either an instrument or an
implant, which may lead to catastrophe because
of the nearby location of the large vessels. During
preparation of the disc space, implant placement,
the surgeon must maintain direct visualization of
the working space. Intraoperative fluoroscopy
may be used to confirm location of instruments
during discectomy and during placement of the
interbody grafts to ensure the anterior annulus is
not violated. If there is a decline in hemodynamics stability at any point after beginning the discectomy, the potential of a vascular injury must
be considered.
Conclusion
The transforaminal lumbar interbody fusion
(TLIF) is a safe and versatile procedure and can
be used to treat a number of degenerative conditions in the lumbar spine. The transforaminal corridor has advantages over other direct posterior
approaches in that it provides direct access to the
disc space and lateral recess with minimal retraction of neural elements through a lateral-tomedial trajectory. TLIF allows for excellent
fusion rates, the ability to provide indirect
decompression and restore segmental lordosis
with relatively low complication rates.
References
1. Madigan L, Vaccaro AR, Spector LR, Milam
RA. Management of symptomatic lumbar degenerative disk disease. J Am Acad Orthop Surg.
2009;17(2):102–11.
2. Eismont FJ, Norton RP, Hirsch BP. Surgical manage-
ment of lumbar degenerative spondylolisthesis. J Am
Acad Orthop Surg. 2014;22(4):203–13.
3. Humphreys SC, Hodges SD, Patwardhan AG, Eck JC,
Murphy RB, Covington LA. Comparison of posterior
and transforaminal approaches to lumbar interbody
fusion. Spine (Phila Pa 1976). 2001;26(5):567–71.
4. Ames CP, Acosta FL Jr, Chi J, Iyengar J, Muiru W,
Acaroglu E, et al. Biomechanical comparison of posterior lumbar interbody fusion and transforaminal
lumbar interbody fusion performed at 1 and 2 levels.
Spine (Phila Pa 1976). 2005;30(19):E562–6.
5. Jagannathan J, Sansur CA, Oskouian RJ Jr, Fu KM,
Shaffrey CI. Radiographic restoration of lumbar alignment after transforaminal lumbar interbody fusion.
Neurosurgery. 2009;64(5):955–63. discussion 63–4
6. Harris BM, Hilibrand AS, Savas PE, Pellegrino A,
Vaccaro AR, Siegler S, et al. Transforaminal lumbar
interbody fusion: the effect of various instrumentation techniques on the flexibility of the lumbar spine.
Spine (Phila Pa 1976). 2004;29(4):E65–70.
7. Heary RF, Bono CM. Circumferential fusion for
spondylolisthesis in the lumbar spine. Neurosurg
Focus. 2002;13(1):E3.
8. Cloward RB. The treatment of ruptured lumbar intervertebral discs; criteria for spinal fusion. Am J Surg.
1953;86(2):145–51.
9. Harms J, Rolinger H. A one-stager procedure in operative treatment of spondylolistheses: dorsal tractionreposition and anterior fusion (author’s transl). Z
Orthop Ihre Grenzgeb. 1982;120(3):343–7.
10. Hackenberg L, Halm H, Bullmann V, Vieth V,
Schneider M, Liljenqvist U. Transforaminal lumbar interbody fusion: a safe technique with satisfactory three to five year results. Eur Spine
J. 2005;14(6):551–8.
11. Heary RF, Kumar S, Karimi RJ. Dorsal lumbar interbody fusion for chronic axial, mechanical low back
pain: a modification of two established techniques.
Neurosurgery. 2008;63(1 Suppl 1):ONS102–6. discussion ONS6–7
12. Awad JN, Moskovich R. Lumbar disc herniations:
surgical versus nonsurgical treatment. Clin Orthop
Relat Res. 2006;443:183–97.
13. Peterson MD, Nelson LM, McManus AC, Jackson
RP. The effect of operative position on lumbar lordosis. A radiographic study of patients under anesthesia in the prone and 90–90 positions. Spine (Phila Pa
1976). 1995;20(12):1419–24.
14. Potter BK, Lenke LG, Kuklo TR. Prevention and
management of iatrogenic flatback deformity. J Bone
Joint Surg Am. 2004;86-A(8):1793–808.
15. Kuklo TR, Lehman RA Jr. Effect of various tapping
diameters on insertion of thoracic pedicle screws:
a biomechanical analysis. Spine (Phila Pa 1976).
2003;28(18):2066–71.
16. Hee HT, Castro FP Jr, Majd ME, Holt RT, Myers
L. Anterior/posterior lumbar fusion versus transforaminal lumbar interbody fusion: analysis of complications and predictive factors. J Spinal Disord.
2001;14(6):533–40.
20 Transforaminal Lumbar Interbody Fusion
249
17. Villavicencio AT, Burneikiene S, Bulsara KR, Thramann
JJ. Perioperative complications in transforaminal lumbar interbody fusion versus anterior- posterior reconstruction for lumbar disc degeneration and instability.
J Spinal Disord Tech. 2006;19(2):92–7.
18. Potter BK, Freedman BA, Verwiebe EG, Hall JM, Polly
DW Jr, Kuklo TR. Transforaminal lumbar interbody
fusion: clinical and radiographic results and complications in 100 consecutive patients. J Spinal Disord Tech.
2005;18(4):337–46.
Percutaneous Spinal Fixation
Ken Hsuan-kan Chang, David McCarthy,
and Michael Y. Wang
Introduction
Pedicle screw fixation has been utilized for the
surgical management of thoracolumbar spinal
deformities, degenerative disease, and trauma
since the middle 1980s [1]. Pedicle screw fixation creates a rigid construct, establishing a stable
spine among destabilizing spinal pathologies,
and further facilitates the process of bone fusion
after fixation. Initially, pedicle screw fixation was
performed as an open procedure; however, as surgical techniques evolved, a minimally invasive
percutaneous screw fixation approach has developed in the last two decades.
Overall, both open screw fixation and percutaneous screw fixation approaches result in similar
radiographic and clinical outcomes [2, 3]. In the
twenty-first century, there has been increased
interest in percutaneous spinal fixation due to its
less invasive nature, technological advances in
devices and imaging, less radiation exposure, and
shorter procedure time. Many physicians that were
K.H.-k. Chang, MD • D. McCarthy, BS
M.Y. Wang, MD, FACS (*)
Department of Neurological Surgery and
Rehabilitation Medicine, University of Miami Miller
School of Medicine, Lois Pope Life Center, 1095
Northwest 14th Terrace, Miami, FL 33136, USA
e-mail: mwang2@med.miami.edu
21
initially trained in the open screw fixation approach
are starting to embrace percutaneous screw fixation nowadays. As surgical techniques and devices
continue to advance, percutaneous screw fixation
is also being adapted for spine deformity and
robotic surgery and has demonstrated the ability to
achieve an equivalent outcome.
In this chapter, percutaneous pedicle screw
(PPS), facet screw, and iliac screw fixation protocol
are described. This chapter will detail the indications/contraindications, preoperative considerations, surgical technique, outcomes, complications,
and new technology for these procedure.
Two-Dimensional Image Considerations (C-arm)
The major breakthrough for the development of
the percutaneous technique was the recognition
and utilization of image guidance when it comes
to pedicle screw fixation. Fluoroscopy-guided
method is by far the most common technique
adopted by spine surgeons in regard to percutaneous screw placement. Unlike open surgery, the
bony landmarks and relative anatomy cannot be
identified through direct visualization in the percutaneous technique. Thus, the entire percutaneous screw placement process relies heavily on a
series of intraoperative fluoroscopic images.
Satisfactory intraoperative fluoroscopic imaging
© Springer International Publishing AG 2017
L.T. Holly, P.A. Anderson (eds.), Essentials of Spinal Stabilization,
DOI 10.1007/978-3-319-59713-3_21
251
252
Fig. 21.1 Illustration of
the critical anatomic
landmarks on a true AP
image
K.H.-k. Chang et al.
is imperative for successful percutaneous screw
placement in minimally invasive (MIS) spine surgery. A radiological technician is the main person
that operates the C-arm during a surgery, although
the spine surgeon is responsible for training the
technicians and collaborating with them during
percutaneous screw placement. Therefore, a surgeon must have the capability to recognize the
adequate two-dimensional images acquired by
C-arm fluoroscopy.
The primary obstacle for intraoperative fluoroscopy is obtaining a clear image with properly
aligned bony structures. A distorted image is usually caused by malalignment of the bone structure, in this case, the target vertebrae. Image
distortion can easily mislead the surgeon, resulting in misplacement of the percutaneous screw in
surgery. To avoid image distortion, the fluoroscope should be manipulated to a certain position
and angle in which the X-ray beam from the
source lies perpendicular to the vertebrae of
interest. The optimal image may be difficult to
capture under certain circumstances, such as
deformity, osteoporosis, obesity, abnormal anatomy, or revision surgery, etc.
A true anteroposterior (AP) fluoroscopic
image is the first step and might be the most useful image when performing K-wire cannulation
for PPS (Fig.
21.1). Lateral fluoroscopic image
is usually the second step and allows the surgeon
to examine if the guidewire and Jamshidi needle
are in an appropriate place inside the pedicle and
vertebral body. The optimal image can be
achieved with several aids. First, the target vertebrae should be placed in the center of the image.
Peripherally placed vertebrae will generate a
parallax phenomenon. In a true AP image, the
C-arm needs to be adjusted to an angle that
makes the superior endplate of the target vertebrae parallel to the central X-ray beam.
Therefore, the superior endplate can appear as
one single superimposed line. The pedicle should
appear as two oval shadows just caudal and lateral to the single superimposed line of superior
endplate (Fig. 21.1). The spinous process has to
be in the true midline of the rectangle image of
vertebrae to complete a true AP image
(Fig. 21.2). In a lateral view, the superior endplate as well as the anterior and posterior border
of the target vertebrae should appear as single
superimposed lines to avoid malrotation of the
fluoroscopic image. The superior and inferior
borders of the pedicle shadow need to be superimposed while performing lateral fluoroscopy.
The pivotal pearl of the percutaneous technique is to always perform the whole procedure
under well-aligned fluoroscopic images. The
interpretation and knowledge of the fluoroscopic
images are essential for minimally invasive spine
surgery.
Indications and Contraindications
Percutaneous screw fixation is indicated in minimally invasive surgery for cases of instability in
degenerative disease, thoracolumbar trauma,
infection, and neoplasia [4]. The cannulation
technique can also be applied for vertebroplasty/k
yphoplasty and vertebral body biopsy. PPS may
be advantageous in comparison to open procedures
for obese patients since the approach and soft tissue dissection are often more significant in such
cases. In theory, percutaneous techniques avoid
21 Percutaneous Spinal Fixation
Fig. 21.2 An adequate anteroposterior (AP) fluoroscopic
image for L4, undergoing Jamshidi needle cannulation.
L5 is already cannulated with a K-wire. The shadow of
superior endplate of L4 is superimposed. The pedicle
shadow is clear and just caudal to the superior endplate.
The spinous process is centered at the midline
the extensive dissection of an open procedure, in
return reducing the rate of wound infection, intraoperative blood loss, total operative time, and
postoperative pain [5].
A contraindication of PPS placement is the
absence of high-quality intraoperative fluoroscopic images. It is unsafe to perform the percutaneous procedure if anatomic landmarks are
unable to be identified on fluoroscopic imaging.
The situation may be encountered in patients
with obesity, osteoporosis, spine deformity, and
congenital abnormality or with inexperienced
surgeons and C-arm technicians. In these situations, navigated image guidance or robotic screw
placement is another option.
Surgical Technique
Percutaneous Pedicle Screw
The patient is almost always positioned prone for
percutaneous pedicle screw (PPS) placement,
although lateral position is sometimes adopted if
PPS procedure follows a lateral lumbar interbody
fusion. A radiolucent table, like the Jackson table
or Allen table, is mandatory for PPS placement
because intraoperative AP fluoroscopic images
253
Fig. 21.3 The tip of the needle is placed laterally to the
lateral border of the pedicle shadow to estimate the appropriate entry point for the Jamshidi needle on the skin
are required. The true AP image technique is
most commonly used for cannulation of the
K-wire in a PPS procedure.
A well-centered AP image for target vertebrae
is checked and is the first and most important step
for PPS placement. Marking the midline can help
the X-ray technician to properly center the X-ray
beam repeatably. Jamshidi needles are often used
for cannulation of the K-wire. The tip of the needle can be placed laterally to the lateral border of
the pedicle shadow before skin incision
21.3). This allows estimation of appropriate
(Fig.
entry point for Jamshidi needles on the skin under
fluoroscopy. The distance between the needle tip
and the lateral border of pedicle is approximately
1 centimeter (cm), but may vary depending on
individual patient conditions such as obesity,
muscularity, body habitus, etc. A 1.5 cm incision
through the skin and fascia is sufficient for
Jamshidi needle and screw insertion. Finger palpation of surface bony landmarks may also facilitate or enhance recognition of the vertebral body
anatomy. Simultaneous placement of the Jamshidi
needle on both sides can save time and reduce
radiation dose.
Jamshidi needles should dock on the junction
between the transverse process and the lateral
border of the facet joint. On AP image, the needle
tip would appear to be placed at the lateral border
of the oval shadow of pedicle. The shaft of the
254
K.H.-k. Chang et al.
Jamshidi needle is then adjusted to maintain parallel position with the superior endplate on AP
image. The Jamshidi needle is then advanced into
the pedicle bone for 2 cm in a proper angle such
that the tip will not breach the medial wall of the
pedicle (Fig. 21.4) [6]. The ideal trajectory of the
Jamshidi needle on AP image is toward the
medial border of the oval shadow of pedicle. The
position of the beveled tip will have an influence
on the direction of needle advancement. If the
bevel is in the lateral position, the needle will
tend to advance in a more slightly medial pathway due to the force vector. In the contrary, the
needle will tend to move forward in a more lateral pathway when the bevel is positioned medially. The surgeon can manipulate the bevel
position to gain a more desirable location of the
needle tip during its advancement. After 2 cm of
advancement, an AP image is obtained to show
that position for the needle tip is just lateral to the
medial border of the pedicle shadow and the needle shaft parallel to the superior endplate
(Fig. 21.5).
The C-arm is then rotated to take lateral fluoroscopic images. An aforementioned superimposed line of superior and posterior border of
vertebrae is critical to certify the bony structure is
well-aligned. Once an optimal image is obtained,
the tip of Jamshidi needle should be very close to
the base of the pedicle. The K-wire is then introduced through the Jamshidi needle into the cancellous bone of the vertebral body. We recommend
to advance the K-wire tip to the anterior half of
the vertebral body on the lateral view. It is important to avoid penetration of the anterior cortex
with the K-wire (Fig. 21.6).
The Jamshidi needle is then removed without
displacing the K-wire. It is important to palpate
the bottom of the K-wire and make sure it is
inside the bone of the vertebral body. The pedicle
bone and part of the posterior half of vertebral
body is tapped over the K-wire (Fig. 21.7). Then,
the cannulated screw is inserted through the
guidewire in a usual manner. The tapping and the
screw insertion should follow the trajectory of
the guidewire (Fig. 21.8). Excessive bending of
the guidewire during the tapping or screw
insertion may result in the unfavorable complication of breakage and retention of the K-wire
inside the bone.
After all the screws are placed, the percutaneous rod is passed. The proper rod length is
selected, and the rod is bent as required to correct
any angular deformities. It is important to pass
Fig. 21.4 Illustration for the true AP technique. A
Jamshidi needle is docked on the bony surface at the junction of the lateral border of the facet joint and transverse
process (a, oblique view; b, lateral view; and c, AP view).
The needle is then advanced into the pedicle bone for
2 cm. The needle tip should not pass the medial border of
the pedicle shadow under AP image (d, oblique view; e,
lateral view; and f, AP view) (Adapted from Ref. [
6])
21 Percutaneous Spinal Fixation
255
Fig. 21.5 The position of Jamshidi needle during cannulation. On the right side of the image, a small diameter
needle is pointing at the 3 o’clock position of the pedicle,
the ideal entry point. On the left side of the image, the tip
of the Jamshidi needle already reaches the medial border
of the pedicle shadow after 2 cm of advancement. This is
the ideal end point for the needle tip
Fig. 21.7 The tapping of the pedicle bone and vertebral
body along the axis of K-wire
Fig. 21.8 Percutaneous screw insertion following the trajectory of the K-wire
Fig. 21.6 The lateral view of K-wire cannulation
the rod as deeply as possible so as to minimize
the amount of muscle compressed underneath it
21.9). There are several different methods
(Fig.
to pass the rod depending on the system used.
One of the common systems adopts a swinging
arm rod inserter which swings the rod in through
a geometrically constrained arc. In another system, the rod insertion is done through one of the
percutaneous skin incisions under the muscular
fascia with direct vision. In other circumstances,
the rod passage for multilevel and deformity
cases can be challenging but is out of the scope
for this chapter. The set screws are then inserted
and torqued as recommended by the manufacturer. If required, extension tabs are broken off.
256
Fig. 21.9 Placement of the rods in the screw heads
Final AP and lateral X-rays are taken to ensure
the construct is in proper place. In traditional
open-pedicle screw insertion, stimulus-evoked
electromyography (EMG) has been applied for
the detection of screw breach and is considered a
useful method to reduce the rate of screw misplacement. However, the utilization of EMG on
percutaneous pedicle screw with insulated sleeve
does not seem to be as reliable as it is in open
cases. Using a typical stimulation threshold
(<12 mA), the ability of detecting low-grade
breached screw is low in percutaneous setting
[7]. In our opinion, intraoperative imaging
remains a more reliable assessment than EMG
for percutaneous pedicle screw.
Alternative Targeting Methods
K.H.-k. Chang et al.
plate shadows should be superimposed and the
superior articular facet aligned properly with the
medial border of the pedicle. The skin incision
should be made directly over the projected image
of the pedicle. Since the cannulation of the
K-wire is parallel to the pedicle and X-ray beam,
the wire usually appears as one spot on the owl’s
eye image. The depth of the cannulation is determined before surgery by measuring on the preoperative CAT scan or MRI. The process of tapping
and screw insertion is similar to aforementioned
AP image procedure. The owl’s eye approach
requires that the right and left pedicles at any
given level be targeted independently.
The mini-open technique involves exposure of
the pedicle screw entry site by splitting the paraspinal muscles and using an expandable tubular
retractor to aid visualization. This method is most
appropriate for short segment (one or two intervertebral discs) PPS placement [10, 11]. After serial
muscle dilators and the retractor are set up properly, electrocautery is used to dissect the soft tissue
around the facet joint and transverse process. This
exposes the bone surface at the junction between
transverse process and the lateral border of the
facet joint. The junction is the ideal entry point for
a gearshift probe or cannulation of guidewire.
After the pedicle is probed or cannulated with a
guidewire, the following procedure to tap the pedicle and insert the screw is very similar to that of
open operation. The mini-open method serves as a
well-combination and modification of minimally
invasive technique and open screw placement
with much less tissue destruction than the traditional open surgery (Fig.
21.11).
If the true AP technique is not feasible or the
image quality is poor, an owl’s eye image may be
an alternative method. The owl’s eye image,
a.k.a. En face view, involves aligning the view
directly with the long axis of the pedicle [8].
The owl’s eye image is obtained by starting with
an AP image, adjusting the sagittal angle, and
centering on target vertebrae and then rotating
the C-arm on the axial plane to align with the
pedicle (Fig.
21.10). When the ideal view of the
owl’s eye image is achieved, the superior end-
Percutaneous Facet Screws
Transfacet screw can be an alternative choice to
pedicle screw. Percutaneous facet screws are
performed less commonly and have a much shorter
track record than pedicle screws. NSR – these
screws are popular among some MIS surgeons. As
with any percutaneous technique, facet screw
placement relies heavily on intraoperative fluoroscopy for guidance. After a small skin incision, for
an L4–L5 facet screw, a Jamshidi needle is placed