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Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_6030_Библиотеки_им_академика_М_И_Перельмана.pdf
A
nterior
A
V
Vertebral
bodies
Stenosis
CSF
Cord
Posterior
C
Brain
Superior
nterior
CSF
fluid
ertebral
bodies
Posterior
Spinal
cord
CSF
visible
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50
Interior
SECTION I THE CERVICAL SPINE
Eurostile
D
Interior
perior edge of the lamina that is the deepest and thickest (usually not fully
resected), and then if the door still does not open, check the hinge groove
depth. If the hinge groove is too deep, it will fracture and destabilize the
door. The door is then held open with No. 1 Ethibond sutures placed
through drill holes in the spinous process and then into the facet capsule
(drill holes should be placed prior to opening the door). It is not uncommon to experience an increase in bleeding after the door is opened due to
the decompression of the epidural venous system at the leading edge (this
can be easily controlled with bipolar electrocautery and thrombin-soaked
Gelfoam). The door should be opened approximately 1 to 1.5 cm. All dural
attachments to the ligamentum flavum are bluntly released with a Penfield. Good dural expansion and pulsations should be visualized. Too aggressive an opening of the laminaplasty may lead to nerve root traction in-
jury, as the spinal cord floats posteriorly. A special eyelet screw can be
placed into the lateral mass.
Closure
Interrupted No. 1 Vicryl for fascia overlying spinous musculature and nuchal ligaments. Anatomic repair of musculature to C2 improves postoperative stability and function.
2. If the cuts are made too lateral, facet destabilization may occur.
3. If the sutures are not placed into the capsule but through the muscle,
they will fail and the door can close.
4. Failure to adequately decompress through poor placement of the bone
cuts and failure to perform foraminotomies when necessary (a gap of
1 cm translates into a 4- to 6-mm translation of the cord) (Fig. 10–3).
Complications of the Technique
1. Neural injury from aggressive bone and soft tissue resection.
2. Neurologic injury from excessive cord migration causing a traction injury to the root (usually resolves spontaneously).
3. Multiple complications due to poor technique and patient selection
that can lead to instability, closure of the door, or inadequate decompression.
Postoperative Management
1. Rigid cervical collar for 6 weeks.
2. Isometric exercises to begin at 2 weeks.
3. X-rays at 2, 6, 12, 24, and 48 weeks.
4. Office follow-up visits at 2, 6, 12, 24, and 48 weeks.
Technique Pearls
1. Place sutures in the spinous processes prior to attempting to open the
door.
2. Always check the superior edge of the laminae if the door does not
open. It is the most common location to have bone remaining.
Pitfalls
1. Meticulous thinning of the lamina on the hinge side. If the groove is too
deep, it can cause fracture and instability.
Suggested Readings
Herkowitz H. A comparison of anterior cervical fusion, cervical
laminectomy, and cervical laminoplasty for the surgical management
of multiple level spondylotic radiculopathy. Spine 1898;13:774–780.
Hirabayashi K, Satomi K. Operative procedure and results of expansive
open-door laminoplasty. Spine 1988;13:870–876.
Shaffrey C, Wiggins G, Piccirilli C, Young J, Lovell L. Modified open-door
laminoplasty for treatment of neurological deficits in younger patients
with congenital spinal stenosis: analysis of clinical and radiographic
data. J Neurosurg (Spine 2) 1999;90:170–177.
Eurostile
10 OPEN DOOR LAMINOPLASTY
51
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11
Posterior Wiring Techniques of the Spine
Alexander R. Vaccaro and Kush Singh
Goals of Surgical Treatment
Wiring techniques of the spine affords semirigid stabilization of the vertebral elements. It is often used as the primary method of fixation in the cer-
vical spine when combined with a rigid external orthosis. Wiring techniques of the thoracolumbar spine are often used in conjunction with other
modes of internal fixation (e.g., rods) to allow rigid segmental stabilization.
If the spinal elements are excessively loaded or the posterior elements are
osteoporotic, wire stabilization alone may not afford adequate immobilization even with supplemental external brace or cast application.
Several techniques have been described to stabilize the occipital-cervical/upper cervical spine. Occipital-cervical and upper cervical spine wiring techniques include the technique of Wertheim and Bohlman (occipitalcervical) and Gallie’s and Brooks‘ methods. Lower cervical wiring techniques include the Rogers, Bohlman, and Dewar methods. Modifications
and adaptations of each method have also been described.
Surgical Approach for Posterior Occipital and Cervical Wire
Application
Posterior occipital and lower cervical wiring procedures are performed
through a midline incision with careful dissection through the fascial
raphe to avoid muscular bleeding. This allows for subsequent exposure of
the intended occipital and posterior cervical elements in a subperiosteal
manner. To avoid excessive vascular bleeding in the upper cervical region
between the C1 and C2 articulation, the thin-walled cavernous venous
plexus is gently elevated at its medial margin with a small patty. Taking
care to avoid disruption of this plexus is important due to its lack of discrete endothelial channels, as this plexus represents a confluence of
venous sinusoids. A bipolar forceps is useful if a small venotomy is encountered. During the exposure of the subaxial spine, only the lateral margin of the lateral masses should be exposed, taking care not to go beyond
this boundary, especially in an anterior direction. One may encounter
dense arterial and venous networks in this area that are difficult to control
without temporary packing. At the completion of the surgical exposure,
any manipulative reduction may be performed followed by placement of
internal fixation (wires) and bone grafting.
Occipital-Cervical Spine
Technique of Wertheim and Bohlman (Fig. 11–1)
Indications
1. Occipitocervical instability
2. Odontoid fracture in the setting of C1 posterior ring incompetence
Contraindications
1. Arnold-Chiari malformation requiring a suboccipital decompression
2. Foramen magnum stenosis requiring significant suboccipital decom-
pression
Advantages
1. Achieves immediate semirigid fixation of the occipital cervical junc-
tion
2. Does not require the passage of wires through both cortices of the skull
and is easily modified to address important anatomical variables
Disadvantages
Requires rigid external orthotic immobilization.
Procedure
Occipital Wiring: At a point 2 cm above the rim of the foramen magnum, a
high-speed diamond bur is used to create a trough on either side of the
occipital crest or inion. This allows the formation of a central bony ridge.
With a towel clip or tenaculum, a hole is made through this bony ridge in-
volving only the outer bony calvarium of the skull. A 20-gauge wire is then
passed through the hole. Another 20-gauge wire is passed in a sublaminar
manner under the arch of the atlas, and an additional wire is passed
through a drill-hole in the base of the spinous process of the axis and
looped around its inferior border. Therefore, on each side of the spine there
are three separate wire ends, which are utilized to secure separate corticocancellous, longitudinally oriented bone struts.
The posterior iliac crest is exposed and the curved portion of the crest,
of the appropriate length and width, is harvested and divided to cover each
side of the intended fusion area. The convex surface of each tricortical
bone graft is decorticated to allow cancellous on cancellous (decorticated
posterior occipital-cervical elements) bony contact. Three drill holes are
then placed in each graft for wire passage. The grafts are then anchored in
place on both sides of the occipital-cervical junction. Additional cancellous bone is packed between the two grafts as needed (Wertheim and
Bohlman, 1987).
Pitfalls
A semirigid form of stabilization often requiring rigid external orthosis
wear for 2 to 3 months.
Complications
Care must be taken to avoid inner calvarium penetration during occipital
drilling or wire passage.
Postoperative Care
Patients are immobilized in a cervicothoracic orthosis or halo vest for 2 to 3
months.
Upper Cervical Spine
Modified Gallie’s Technique (Gallie, 1937, 1939) (Fig. 11–2)
Indications
1. C1-C2 instability
2. Odontoid fracture
Contraindications
Posterior (C1 or C2) element deficiency
Advantages
Technically simple
Disadvantages
1. Less biomechanically stable than the Brooks technique (see below)
2. Suboptimal stability in extension, translation, and rotation
Procedure
At the completion of exposure of the posterior cervical elements, the soft
tissue attachments to the C1 lamina (occipital atlantal and atlantoaxial
membranes) are elevated in a subperiosteal manner. A Woodson probe is
placed beneath the C1 lamina in a caudad and cephalad direction to make
sure it is free of any soft tissue attachments. A doubled-over 16- or 18-gauge
wire is then shaped in a semilunar fashion and gently passed in a caudad to
cephalad direction beneath the C1 lamina (Fig. 11–2A).
A corticocancellous block of autologous bone is harvested from the iliac
crest, and a notch is created at its inferior border to straddle the C2 spinous
process. The upper margin of the graft is positioned dorsal to the C1 arch
(Fig. 11–2B). The leading edge of the wire loop is then brought over the
graft and opened to loop around the C2 spinous process. The free wire ends
are then brought around the sides of the graft and tied to each other over the
dorsal surface of the bone graft (Fig. 11–2C).
Pitfalls
Care must be taken not to posteriorly displace the C1 vertebral body during
wire manipulation or tightening.
Complications
This mechanical construct weakly resists translation, rotation, and extension compared with the modified Brooks technique for C1-C2 fixation
(White and Panjabi, 1978).
Postoperative Care
The patient is usually kept in a cervicothoracic orthosis or halo vest for approximately 2 to 3 months to allow for bony healing. Early after surgery the
patient is encouraged to carry out general isometric neck muscle exercises.
Modified Brooks Techniques (Fig. 11–3)
Indications
1. C1-C2 instability
2. Odontoid fracture
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52
SECTION I THE CERVICAL SPINE
Eurostile
Figure 11–1
Wertheim and Bohlman technique for occipitocervical fusion. The occiput, C1, and C2 are fused with midline wires and a pair of bone struts.
Type II fracture
Partially decorticated
spinous process
A
Figure 11–2
(A–C) Modified Gallie technique. A bone graft is secured over the posterior arches of C1 and C2 by passing a single wire under the arch of C1 and looping it over the spinous
process of C2.
Wire
(subperiosteal)
Eurostile
Bone graft
B
11 POSTERIOR WIRING TECHNIQUES OF THE SPINE
53
C
■
A
Figure 11–3
Modified Brooks fusion. (A) C1 and C2 are fused by placing bone wedges posteriorly in between their lamina. (B) Wires are then passed from below under the lamina of C2
and C1, securing the two segments and bone graft together.
B
Figure 11–4
Rogers technique. Two adjacent cervical spinal segments are secured by the passage of a looped interspinous process wire.
■
54
SECTION I THE CERVICAL SPINE
Eurostile
Tighten with
Notches
for wire
large needle
holder
A B
Figure 11–5
(A,B) The Bohlman’s triple wire technique is similar
to the Roger’s technique except for the addition of
spinous process wires that function to secure two
cortical cancellous bone graft stents over the posterior elements of the intended fusion area.
A
BC
Figure 11–6
(A–C) Subaxial cervical sublaminar wire technique. Sublaminar wires are carefully passed under the lamina of each segment only with direct visualization of the dura to
prevent neural compression.
Eurostile
11 POSTERIOR WIRING TECHNIQUES OF THE SPINE
55
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Figure 11–7
A B
Dewar fusion. (A) The cervical vertebrae are initially decorticated and then stabilized with Steinmann pins. (B) These are then passed through both the vertebrae and adja-
cent corticocancellous strut-grafts.
Figure 11–8
Oblique facet wiring. A wire is passed through a drill hole in the inferior cervical articular process. The wire is then passed through the spinous process of the inferior vertebra to secure the vertebral interspace.
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56
SECTION I THE CERVICAL SPINE
Eurostile
Figure 11–9
Thoracolumbar sublaminar wire passage. The wire utilized is often a 16- or 18gauge wire looped on itself to allow the smooth looped cord to be the leading surface during passage.
Graft
C
AB
Pars-interarticularis
defect
Tighten wires
Figure 11–10
(A–C) Scott technique. A bone graft is secured in the decorticated pars interarticularis defect by looping a wire around the transverse process and spinous process of the respective vertebrae.
Eurostile
11 POSTERIOR WIRING TECHNIQUES OF THE SPINE
57
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Contraindications
1. Spinal stenosis
2. Posterior (C1 or C2) element insufficiency
Advantages
1. Technically simple
2. Greater resistance to translation, rotation, and extension than the
Gallie fusion (White and Panjabi, 1978).
Disadvantages
Risk of neural injury with C1 and C2 sublaminar wire passage
Procedure
At the completion of exposure of the posterior cervical elements, the soft
tissue attachments to the C1 and C2 laminar (occipital atlantal membrane,
atlantoaxial membrane, and ligamentum flavum) are elevated in a subperiosteal manner. A Woodson probe is then placed beneath each lamina from
a caudal and cephalad direction to make sure they are free of any soft tissue
attachments. A vascular needle is then selected of the appropriate size and
its needle edge is removed with a cutter. A 1–0 silk thread is then tied
through the eye of the needle and this end is then passed in a caudal to
cephalad direction beneath the C2 and C1 lamina with the silk thread trailing behind. The silk thread is then tied to a doubled-over 16- or 18-gauge
wire shaped in a semilunar fashion, which is then gently pulled beneath
the lamina by the silk suture. A Woodson is placed beneath the sublaminar
wire as it passes between C1 and C2 to prevent posterior thecal sac compression. Wires are passed on both sides of the spine. Two trapezoidalshaped corticocancellous autologous iliac crest bone wedges are harvested
and positioned bilaterally between the decorticated posterior C1 and C2
laminae (Fig. 11–3A). The wires on each side are then twist tightened over
the grafts securing the bone wedges into position (Griswold et al, 1978)
(Fig. 11–3B).
Pitfalls
1. Overtightening suboptimally sized grafts may lead to posterior dis-
placement of the C1 ring and subsequent loss of cervical alignment.
2. The use of cables, which are technically easier to apply than wires due
to their flexibility, may result in rare instances of late posterior thecal
sac compression as the bone grafts resorb and the cable returns to a
circular shape due to its inherent elastic memory.
Complications
1. The major disadvantage of this technique is that it requires sequential
sublaminar wire passage beneath C2 and C1, with the rare potential for
neurologic injury.
2. Delayed healing or nonunion due to lack of rigid stability as offered by
various screw fixation techniques.
Postoperative Care
The patient is usually kept in a cervicothoracic orthosis or halo vest for approximately 2 to 3 months to allow for bony healing. Early after surgery the
patient is encouraged to carry out general isometric neck muscle exercises.
Lower Cervical Spine
Rogers Technique (Fig. 11–4)
Indications
1. Ligamentous instability of the lower cervical spine
2. Pure interspinous ligamentous disruption
3. Flexion-distraction injury with facet subluxation/dislocation
4. Fracture dislocation/subluxation
5. Following a multiple level anterior cervical decompression and fusion
for added stability
Procedure
A transverse hole is placed at the junction of the spinous process and the
lamina (spinolaminar line) of the vertebral levels to be fused. The starting
hole is made on either side of the spinous process base and completed
using either a towel clip or bone tenaculum. Once the holes are completed,
a 16- to 18-gauge wire is passed through the completed channels and then
looped around its superior spinous process border and again through the
created passageway or channel. A similar wire passage technique is used
for the caudal vertebral level, with the wire being looped around the inferior spinous process border. The starting point of hole preparation for the
cephalad vertebral level is at the superior third of the spinolaminar line
and at the inferior third of the spinolaminar line for the caudal vertebral
level. The free wire ends of both levels are then secured to their respective
partners on each side of the spine. The method of cable placement is modified in that only one wire cable is utilized. Once the cable has been passed
through and looped around one spinous process, the free end (male portion) of the cable is then passed though and looped around the adjacent
vertebral level. The male end now engages its female counterpart prior to
tightening and crimping (Rogers, 1942; Songer et al, 1991).
Pitfalls
Semirigid fixation is not especially useful in the setting of anterior vertebral body insufficiency.
Complications
1. Inadvertent failure or breakage of the spinous process during wire/
cable placement or tightening.
2. The most common complication associated with any wiring procedure
in the cervical spine is loss of fixation and subsequent recurrence of
deformity. This complication is directly related to bone quality, the
surgeon’s technique, and postoperative external support.
Postoperative Care
The patient is usually kept in a cervicothoracic orthosis or halo vest for approximately 2 to 3 months to allow for bony healing. Early after surgery the
patient is encouraged to carry out general isometric neck muscle exercises.
Bohlman’s Triple-Wire Technique (Fig. 11–5)
Indications
1. Ligamentous instability of the lower cervical spine
2. Pure interspinous ligamentous disruption
3. Flexion-distraction injury with facet subluxation/dislocation
4. Fracture dislocation/subluxation
5. Following a multiple level anterior cervical decompression and fusion
for added stability
Contraindications
1. Loss of structural integrity of the posterior cervical elements
2. Alone in the setting of three-column instability
Advantages
1. Minimal risk of neurologic embarrassment
2. Simple technically
3. Inexpensive
4. Superior biomechanical strength versus other posterior wiring techniques such as the Rogers method
Disadvantages
1. Requires intact posterior cervical elements
2. Requires adequate availability of tricortical iliac bone graft-size of
bone graft may increase the risk of bone graft site morbidity
3. Suboptimal stability in extension and rotation
Contraindications
1. Loss of structural integrity of the posterior cervical lamina
2. Alone in the setting of three-column instability
Advantages
1. Minimal risk of spinal cord compression or neurologic injury
2. Technically simple
3. Inexpensive
Disadvantages
1. Less stable in extension and rotation
2. Requires intact posterior cervical laminal elements
3. Bone graft not rigidly secured
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58
SECTION I THE CERVICAL SPINE
Eurostile
Procedure
A transverse hole is placed at the junction of the spinous process and the
lamina (spinolaminar line) of the vertebral levels to be fused. The starting
hole is made on either side of the spinous process base and completed
using either a towel clip or bone tenaculum. Once the holes are completed
a 16- to 18-gauge wire is passed through the completed channels and then
looped around its superior spinous process border and again though the
created passageway or channel. A similar wire passage technique is used
for the caudal vertebral level, with the wire being looped around the inferior spinous process border. The starting point of hole preparation for the
cephalad vertebral level is at the superior third of the spinolaminar line
and at the inferior third of the spinolaminar line for the caudal vertebral
level (Fig. 11–5A). The free wire ends of both levels are then secured to
their respective partners on each side of the spine. The method of cable
placement is modified in that only one wire cable is utilized. Once the
cable has been passed through and looped around one spinous process, the
free end (male portion) of the cable is then passed though and looped
around the adjacent vertebral level where it engages its female counterpart
prior to tightening and crimping (Fig. 11–5B).
In practice, frequently only a single wire or cable for this portion of the
procedure is used. This wire is passed through the created channels in the
respective vertebral levels and then twisted to itself without being looped
around the outer borders of the spinous processes. A separate wire is then
passed individually through each created channel. The ends of each wire
are passed through holes made along a corticocancellous iliac strut graft,
which is secured to the decorticated cervical laminae as the ipsilateral wire
ends are twisted to one another. The graft sizes are shaped in length to maximize bone-to-bone contact along the desired vertebral levels to be fused
(McAfee et al, 1985).
Pitfalls
1. This technique is the most stable biomechanical method of wire stabi-
lization of the subaxial spine.
2. However, it is still considered a semirigid form of stabilization and
may not be adequate alone in the setting of significant anterior column
insufficiency.
Complications
1. Inadvertent failure or breakage of the spinous process during wire
cable placement or tightening.
2. The most common complication associated with any wiring procedure
in the cervical spine is loss of fixation and subsequent recurrence of
deformity. This complication is directly related to bone quality, the
surgeon’s technique, and postoperative external support.
Postoperative Care
The patient is usually kept in a cervicothoracic orthosis or halo vest for approximately 2 to 3 months to allow for bony healing. Early after surgery the
patient is encouraged to carry out general isometric neck muscle exercises.
Subaxial Cervical Sublaminar Wiring (Fig. 11–6)
Indications
To secure a rod (or plate) to the subaxial vertebral posterior elements, that
is, box Luque, especially at the cervicothoracic junction.
Contraindications
1. Previous laminectomy
2. Cervical stenosis
Advantages
1. Segmental stabilization of cervical spinal elements at the cervi-
cothoracic junction
2. Technically easy
Disadvantages
1. Risk of spinal cord injury with sublaminar wire passage.
2. Cables are much more user friendly due to their flexibility and ease of
handling.
Procedure
Once the desired cervical levels are exposed, the ligamentum flavum is ele-
vated in a subperiosteal manner with a 3–0 curved cervical curet from the
superior and inferior border of the respective lamina (Fig. 11–6A). The free
ends of the ligamentum flavum are then sharply removed with a 1–0 Kerrison punch. The male end of a stainless steel or titanium cable is folded
back on itself (so as to have a blunted tip for a leader), and the leading edge
is then passed underneath the lamina from a caudad to cephalad direction
(Fig. 11–6B). This procedure is performed bilaterally. Prior to tightening
the cables around a contoured rod or plate, the cables are secured to the
drapes or skin with a snap to avoid cable migration into the cervical canal
(Wilber et al, 1991) (Fig. 11–6C).
Pitfalls
Subaxial sublaminar wire passage should be discouraged as a routine form
of fixation for instability disorders of the cervical spine due to the limited
space available between the posterior cervical elements and spinal cord.
Complications
1. Catastrophic neurologic injury from spinal cord compression during
wire passage in the subaxial cervical spine. Meticulous attention to
detail is required, and all compressive pathology should be removed
with the dura well visualized prior to wire passage.
2. The most common complication associated with any wiring procedure
in the cervical spine is loss of fixation and subsequent recurrence of
deformity. This complication is directly related to bone quality, the
surgeon’s technique, and postoperative external support.
Postoperative Care
Use of a cervicothoracic brace or halo vest for 2 to 3 months until adequate
bony healing occurs.
Dewar Fusion (Fig. 11–7)
Indications
1. Ligamentous instability of the lower cervical spine
2. Pure interspinous ligamentous disruption
3. Flexion-distraction injury with facet subluxation/dislocation
4. Fracture dislocation/subluxation
5. Following a multiple level anterior cervical decompression and fusion
for added stability
Contraindications
1. Loss of structural integrity of the posterior cervical lamina
2. Alone in the setting of three-column instability
Advantages
1. Minimal risk of neurologic embarrassment
2. Simple technically
3. Inexpensive
4. Stiffer biomechanically than the Rogers technique
Disadvantages
1. Requires intact posterior cervical elements
2. Requires adequate availability of tricortical iliac bone graft-size of
bone graft may increase the risk of bone graft site morbidity
3. Suboptimal stability in extension and rotation
Procedure
Two-millimeter Steinmann pins are passed percutaneously through iliac
corticocancellous strut grafts that have been contoured and placed along
the posterior cervical elements of the proposed fusion levels. The pins are
passed through the spinous process and out through a graft placed on the
contralateral posterior cervical element before they are cut, leaving enough
length to secure a wire around their edges (Fig. 11–7A). A 20-gauge stainless steel wire is then looped around the four wire ends in a figure-eight
fashion and twisted to itself to compress the bone grafts to the posterior
cervical spine (Davey et al, 1985) (Fig. 11–7B).
Pitfalls
1. The technical difficulty of placing the Steinmann pin accurately
through the sandwiched spinous process
2. Preventing the strut graft on the contralateral side of pin insertion from
elevating off the posterior cervical elements when being penetrated by
the Steinmann pin
Complications
1. Canal penetration may occur during Steinmann pin placement if great
caution is not taken in predetermining the drilling path.
2. The most common complication associated with any wiring procedure
in the cervical spine is loss of fixation and subsequent recurrence of
deformity. This complication is directly related to bone quality, the
surgeon’s technique, and postoperative external support.
Postoperative Care
The patient is usually kept in a cervicothoracic orthosis or halo vest for approximately 2 to 3 months to allow for bony healing. Early after surgery the
patient is encouraged to carry out general isometric neck muscle exercises.
Oblique Facet Wiring (Fig. 11–8)
Indications
1. Rotational instability of the subaxial spine, i.e., unilateral facet subluxation or dislocation
2. Subaxial spine stabilization following a laminectomy
Eurostile
11 POSTERIOR WIRING TECHNIQUES OF THE SPINE
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