Subaxial spine (2)

SUBAXIAL CERVICAL SPINE
SAURABH SHARMA

Anatomy-‐
• 3 columns-‐Anterior, middle
and Posterior
• Anterior-‐ALL, Ant 2/3 rd
body & disc.
• Middle-‐Post 1/3rd of body
&disc, PLL
• Posterior-‐Pedicle, lamina,
facet, transverse process,
spinous process, Ligaments-‐
Interspinous, lig.ﬂavum
• Articulations-‐Disc-‐vertebral
body, Uncovertebral ,
Zygapophyseal joints.
2

Cervical spine injuries
3
• Common cause of disability
• Incidence
– Spine without cord injury-‐ 3%
– Cord without #-‐0.7%
• Most commonly involves C5 and C6 levels.
• Primarily involves adolescents and young adults
• Males predominate.
• Most common causes-‐
– RTA, Fall, Penetrating trauma, Sports

Clinical features
4
• Neck pain
• Restriction of neck movements
• Neck tenderness
• Varying degrees of neurological deﬁcits
– Complete cord syndrome
– Incomplete cord syndrome
• Central cord syndrome
• Brown-‐Sequard syndrome
• Anterior cord syndrome
• Combination

Mechanisms of injury
A-‐Axialcompression force;
5
B-‐Hyperextension injury; C-‐Hyperﬂexioninjury

By mechanisms of injury
6
• Flexion
– Anterior subluxation
– Unilateral facet dislocation
– Bilateral facet dislocation
– Wedge compression fracture
– Flexion teardrop fracture
– Clay Shoveler's fracture
• Extension
– Hangman's fracture
• Compression
– Jeﬀerson fracture
Burst fracture
• Complex
– Odontoid

IMAGING
Lateral view
•
•
•
•
– Disc spaces, vertebral
body, facet joints
AP view-‐Spinous
process,
Uncovertebral joints
Oblique view-‐
Foramina, pedicles,
facet joints, lateral
mass, lamina

• Up to 20 % of fractures are missed on
conventional radiographs.
• The sensitivity and speciﬁcity of CSR to detect
fractures around 31.6 and 99.2%, respectively.
• For radiographic clearance of the cervical
spine-‐CT is a must.
• CT-‐Excellent details about the # morphology.

Classiﬁcation
• AO SPINE
• SLIC
• Allen
10

AO spine classiﬁcation
• Based on 2 column concept of Nicolle and Holdsworth.
• Similar to the ones of thoraco-‐lumbarinjuries
• Isolated spinous/ transverse process # not considered.
• Type B and type C injuries are the dominating cervical spinal
injuries.
• The severity in terms of instability of the injuries as well as the rate
of neurological deﬁcits does not continuously increase from A to C
in the cervical spine as it does in the thoracolumbar spine.

Cervical Spine Fractures Classification
System 5
Compression injuries
Type Description
AO
No bony injury or minor injury such as an isolated lamina fracture or spinous process fracture
A1
Compression fracture involving a single endplate without
involvement of the posterior wall of the vertebral body
A2
Coronal split or pincer fracture involving both endplates without
A3 Burst fracture involving a single endplate with involvement of the posterior vertebral wall
A4 Burst fracture or sagittal split involving both endplates

System
6
Distraction injuries
Type Subtype Description
B1
Posterior Tension Band
Injury (bony)
Physical separation through fractured bony structures only
B2
Posterior Tension Band Injury
(bony Capsuloligamentous,
ligamentous)
Complete disruption of the posterior capsuloligamentous
or bony capsuloligamentous structures together with a
vertebral body, disk, and/or facet injury
B3 Anterior Tension Band Injury
Physical disruption or separation of the anterior
structures (bone/disk) with tethering of the posterior
elements

System 7
Translation injuries
Type Description
C
Translational injury in any axis-displacement or translationof one vertebral
body relative to another in any direction

System
8
Facet injuries
Type Description
F1
Nondisplaced Facet Fracture with fragment <1cm in height, <40% of lateral mass
F2 Facet fracture with fragment >1cm, > than 40% lateral mass, ordisplaced
F3 Floating lateral mass
F4 Pathologic subluxation or perched/dislocated facet
BL Bilateral injury

System 9
Neurology
Type Description
NO
Neurologically Intact
N1 Transient neurologic deficit
N2 Radiculopathy
N3 Incomplete spinal cord injury
N4 Complete spinal cord injury
NX Neurological status unknown
+ Ongoing cord compression in setting of incomplete neurologic deficit or nerve injury

System
1
0
Modifiers
Type Description
M1
Posterior Capsuloligamentous Complex injury without complete disruption
M2 Critical disk herniation
M3 Stiffening/metabolic bone disease (ie.: DISH, AS, OPLL, OLF)
M4 Vertebral artery abnormality

System 11
Injuries are first classified by their level and primary injury type, either C, B, orA. If there are
multiple levels, the most severe level is classified first. The secondary injuries are
parenthesized.
For example, a C6-C7 translational injury (C) with a C7 compression fracture (A1) would be classified as:
C6-C7:C
(C7:A1)
And a C5-C6 flexion distraction injury (B2) with a C6 compression fracture (A1) would be
classified as:
C5-C6:B2
(C6:A1)
Classification

System
1
2
Included in parenthesis are the remaining subgroups in the
order of: facet injuries, neurological status, and any
modifiers.
For bilateral facet injuries, the “BL”modifier is added after the facet injury if the injuries are
the same.
For example, a C6-C7 flexion distraction injury (B2) with bilateral facet dislocation (F4) would be classified as:
C6-C7:B2
(F4BL)
When there are different facet injuries to the same level, the right side is listed first, then
the left.
For example, a C6-C7 flexion distraction injury (B2) with right sided facet
dislocation (F4) and a left sided displaced facet fracture (F2) would be classified
as:
C6-C7:B2
(F4,F2)
If there are multiple injuries to the same facet (For example: small fracture (F1) and
dislocation (F4), only the highest level facet injury is classified (F4).
If only facet injuries are identified (No A, B, or Cinjury), they are listed first after the level of
injury.
Classification–Facet
Injuries

System 13
A0. Nobony injury orminor injury such as an isolated lamina fracture
orspinous process fracture
TypeA: Compression injuries

System
1
4
A1. Compression fracture involving a single endplate without

System 15
A1. Compression fracture involving a single endplate without

System
1
6
A2. Coronal split orpincer fracture involving both endplates without

System 17
A3. Burst fracture involving a single endplate with
involvement of the posterior vertebral wall

System
1
8
A3. Burst fracture involving a single endplate with
involvement of the posterior vertebral wall

System 19
A4. Burst fracture orsagittal split
involving both endplates

System
2
0
A4. Burst fracture orsagittal split
involving both endplates

System
1
2
Included in parenthesis are the remaining subgroups in the
order of: facet injuries, neurological status, and any
modifiers.
For bilateral facet injuries, the “BL”modifier is added after the facet injury if the injuries are
the same.
For example, a C6-C7 flexion distraction injury (B2) with bilateral facet dislocation (F4) would be classified as:C6-C7:B2
(F4BL)
When there are different facet injuries to the same level, the right side is listed first, then
the left.
For example, a C6-C7 flexion distraction injury (B2) with right sided facet
dislocation (F4) and a left sided displaced facet fracture (F2) would be classified
as: C6-C7:B2
(F4,F2)
If there are multiple injuries to the same facet (For example: small fracture (F1) and
dislocation (F4), only the highest level facet injury is classified (F4).
If only facet injuries are identified (No A, B, or Cinjury), they are listed first after the level of
injury.
Classification–Facet
Injuries

System
2
2
B1. Posterior tension band injury (bony)
Type B: Distractioninjuries
Physical separation through fractured bony structures only

System 23
B2. Posterior tension band injury
(bony capsuloligamentous,
ligamentous)
Complete disruption of the posterior capsuloligamentous or bony
capsuloligamentous structures together with a vertebral body, disk,
and/or facet injury

System
2
4
B3. Anterior tension band injury
Physicaldisruptio
n or separation
ofthe anterior
structures
(bone/disk) with
tethering of the
posterior
elements

System 25
C.Translational injury
Type C: Translationinjuries

System
2
6
F1. Nondisplaced facetfracture
(Fragment <1cm, < 40% lateral
mass)
Facetinjuries

System 27
F2. Facet fracture with fragment >1cm,
> 40% lateral mass or displacedFacetinjuries

System
2
8
F3. Floating lateral mass
Facetinjuries

System 29
F4. Pathologic subluxation orperched/dislocated facet
Facetinjuries

System
3
0
Facetinjuries

System 31
Facetinjuries

System
3
2
BL. Bilateral injury
Facetinjuries

System 33
C7-T1: C
(T1:A1; F4 BL;
N4)
(assume
bilateral)
Case Example 1.
25 year old male involved in high speed MVA,completeSCI

System
3
4
C7-T1: C
(T1:A1; F4 BL;
N4)
Translational injury (C), with compression
fracture at T1 (A1), bilateral facet dislocations
(F4 BL), complete SCI (N4)
(assume
bilateral)
Case Example 1.
25 year old male involved in high speed MVA,completeSCI

System 35
C5: F2, C6:
F2 (N2; M1)
Case Example 2.
42 year old male involved in high speed MVA,radiculopathy

System
3
6
C5: F2, C6:
F2 (N2; M1)
C5 and C6 displaced facet fractures (F2),
radiculopathy (N2), posterior
capsuloligamentous complex injury without
complete disruption (M1)
Case Example 2.
42 year old male involved in high speed MVA,radiculopathy

FIGURE 3. Reformatted computed
tomography (Compressive Flexion,
Vertical Compression, Distractive
Flexion and Compressive Extension)
and magnetic resonance (MR) views
(Distractive Extension) of the
Mechanistic Classification of Allen
and associates. Each phylogeny can
have several stages of injuries.
Copyright © 2017 by the Congress of Neurological Surgeons 55

FIGURE 7. Reformatted sagittal
computed tomography views
of cervical spine indicating
distractive flexion (DF) stages 2
to 4 of Allen et al
Classification. In DF stage 2 (A),
there is unilateral locked
facets. In DF stage 3 (B) facets
are bilaterally locked with
partial translation of the
rostral vertebral body and in
DF stage 4 (C) there is
significant translation of the
rostral vertebral body in
conjunction with bilateral
locked facets.

FIGURE 8. Reformatted axial
computed tomography
indicating a typical floating
lateral mass of C5 vertebral
body compatible with
compressive extension (CE)
stage 1 (A), and reformatted
sagittal computed tomography
views of cervical spine
indicating fracture of the
superior articulating processes
of C7 bilaterally compatible
with CE stage 4 of Allen et al
Classification (B).

FIGURE 9. 73-year-old male
who sustained a free fall down
a flight of stairs with his
forehead striking a dry wall.
Reformatted Sagittal views of
CT (A) and MRI (C) and
reformatted CT axial view (B)
of C6 indicate translation and
disruption of posterior arches
at C6. This patient also had
fractures of posterior arch at
C5 and C7 (A and C). ASIA
motor score at admission was
14 and ASIA Impairment Scale
(AIS) A. The findings on
imaging studies and the
history were compatible with a
compressive extension injury
phylogeny Stage 5 of Allen
Classification.

FIGURE 10. Sagittal
reformatted views of cervical
spine indicating distractive
extension stage 2 of Allen
Classification.

FIGURE 11. Mildest form of
flexion injury proposed by
Harris. Sagittal angulation
associated with increased
interspinous ligament is
conjunction with disruption of
capsular ligaments.

TABLE 1 Stability Checklist as
Suggested by White and
Panjabia

Table 2
TABLE 2 Subaxial Injury Classification and
Severity Scale as Suggested by Vaccaro and
Colleagues37,38

SLIC>5• Surgical
SLIC<3
• Conservative
SLIC=4• Equivocal
>
5
<3
=
4
SLIC

Management
65
• Assess ABC
• Initial neck immobilization in a hard collar.
• Assess neurological status.
• Check for associated injuries.
• Role of steroids-‐Not a guideline
• Imaging-‐Digital X ray C-‐spine,NCCT spine+/-‐ MRI
• Conservative v/s surgical management

Goals of treatment
66
• A pain free patient with normal spinal function and a
clinically stable spine
• The maintenance or recovery of neurological function
by reduction and decompression of neural elements.
• Restoration of a physiological spinal alignment.
• A deﬁnite bony healing of a surgically fused spinal
segment.
• An as-‐short-‐as possible stabilization and fusion
• Number of segments involved in surgical management
to be kept to a minimum.

Conservative treatment
67
• Can be done in less severe deﬁcits (ASIA D,E)
• Cervical traction
• Early mobilization (to prevent chest infections
and bedsores)
• Physiotherapy (Limb and chest)

SURGICAL TREATMENT
68
• Timing of surgery
• Type of surgery ( Anterior/ Posterior/
Combined)

Timing of surgical intervention
69
• No clear consensus yet.
• Currently no standards regarding the role and timing of
decompression in acute SCI.
• For injuries of the cervical spine there is some evidence that
neurological recovery improved when the dislocation was reduced
as early as possible
– Indication, surgical technique and surgical results of 100 surgically
treated # and #-‐dislocations of cervical spine. Clin Orthop Relat Res;
(203):244–257.
• Currently no standards regarding the role and timing of
decompression in acute SCI.
• Role of surgical decompression in patients with SCI is only
supported by Class III and limited Class II evidence.
– J Neurosurg. 1999 Jul;91(1 Suppl):1-‐11.

Early treatment in acute central cord injuries
70
– Reasonable and safe to consider early surgical decompression (<24
hrs) in patients with profound neurologic deficit (ASIA = C) and
persistent spinal cord compression due to developmental cervical
spinal canal stenosis without fracture or instability.
• Spine (Phila Pa 1976). 2010 Oct 1;35(21 Suppl):S180-‐6.
– Surgical intervention consisting of Open door expansile cervical
laminoplasty can be safely applied in the subset of patients with
ATCCS without instability who have significant cervical spondylosis/
stenosis. 29 cases. Average delay from injury to surgery was 3 days.
• Surg Neurol. 2005 Jun;63(6):505-‐10
– Surgical decompression, however, was associated with immediate
neurologic improvement, faster recovery of neurologic function, early
mobilization, better long-‐term neurologic outcome, briefer hospital
stays, and fewer complications related to long confinements in bed
than was nonoperative treatment. 13/16 showed improvement.
• Spine (Phila Pa 1976). 1998 Nov 15;23(22):2398-‐403.

• Recommended-‐Urgent decompression of bilateral
locked facets in a patient with incomplete tetraplegia
or in a patient with SCI with neurologic deterioration.
Urgent decompression in acute cervical SCI remains a
reasonable practice option and can be performed
safely. There is emerging evidence that surgery within
24 hours may reduce length of intensive care unit stay
and reduce post-‐injurymedical complications.
71
• 66 articles were reviewed including 1 RCT
– Spine (Phila Pa 1976). 2006 May 15;31(11 Suppl):S28-‐35.

Anterior approaches
72
• Discectomy and fusion.
• Corpectomy
• Anterior cervical plating

Posterior approaches
40
• Posterior wiring technique and bone grafting approach
– Injuries of the posterior complex involving predominantly
soft tissue with insigniﬁcant damage to the vertebral body.
– Enhancement of other posterior fusion techniques.
• Lateral mass ﬁxation
– Posterior stabilization of the cervical spine from C3 to C7.
– Biomechanically stronger than posterior wiring techniques
and anterior plating
– Risks of injury to the vertebral artery and segmental nerve.
• Others-‐ not generally performed nowadays
– Interlaminar clamps
– Sublaminar wiring

• The cervical spine is the most mobile portion of the spinal
column and its stabilization has unique features.
• Cervical spine stabilization may be performed using anterior,
posterior, or combined techniques
• Anterior fusion techniques were first introduced in 1955 by
Smith and Robinson and then popularized by Cloward

• The first application of a metal plate as a supplement to an
anterior bone graft in cases of cervical dislocation was
performed in 1975 by Herrmann.
• In 1980, Böhler also used small plates as proposed by Orozco
and Llovet.
• In 1980 Caspar popularized the use of anterior cervical plates,
resulting in more widespread use of Caspar plating in the mid-
1980s in both Europe and the United States.

• Ideal cervical instrumentation must provide an immediate
stability to the motion segment, allow high rates of fusion,
correct deformity in any plane, and be low profile and easy to
apply.
• The risk of hardware failure must also be minimal, and
instrumented constructs should ideally be radiolucent and not
ferromagnetic so as to cause minimal artifact on magnetic
resonance imaging (MRI).

Anterior Stabilization Techniques
• Anterior cervical plates have significantly changed since their
early application in cervical trauma.
• They are now common place in anterior cervical
decompression and fusion (ACDF) procedures, especially in
cases requiring decompression of two or more levels.
• The first anterior cervical plates were unlocked and required
bicortical purchase.
• The latest plates are semiconstrained dynamic plates that
allow some movement in rotation and translation

BIOMECHANICS OF CERVICAL PLATES
• Anterior cervical plates must hold the interbody graft in place and provide
immediate rigidity
• Optimize the fusion environment and increase the fusion rate and improve clinical
outcomes.
• The plate–graft relationship is another important factor to consider during
anterior cervical surgery.
• A satisfactory amount of graft loading is necessary in order to achieve bony fusion.
• A very rigid plate can cause the bone graft to resorb, or it can result in
pseudarthrosis owing to inadequate graft loading.
• In the case of weaker constructs, anterior column height can decrease owing to
graft subsidance into the adjacent endplates.
• Plates bear and share loads and behave like a ventral tension band mechanically,
thereby building a barrier that limits vertical and horizontal translation of the
spine. This is particulary the case in extension.
• In the case of three-column injuries, anterior cervical plates provide little stability
in flexion and rotation, so either external fixation in a halo jacket or combined
posterior supplemental fixation is required to achieve adequate spinal stability.

• Plate–screw constructs increase the rigidity of the injured spinal segment,
they cannot restore the strength of a normal healthy spine.
• In other words, an uninjured spine is stronger than an injured and
internally fixated one.
• In the case of excessive loading, instrumentation can fail through fracture
or screw pullout.
• For these reasons, consideration should be given to external bracing or
additional supplemental fixation to provide additional load sharing with
the anterior construct.
• Screw choice and insertion technique also affect the biomechanical
properties of anterior plating.
• Hollow screws with small holes on the shaft were developed to allow
improved osteointegration at the screw–bone interface. They were
removed from the market because of high screw fracture rates and
increased difficulty of removal

• Medial or lateral angulation of anterior screws during
insertion results in a triangulation in the axial plane, whereas
cranial and caudal angulation results in sagittal plane
triangulation.

• Which plate should be used, constrained or nonconstrained?
• Should screws be placed in a unicortical or bicortical fashion?
• Should a screw be placed into the interbody bone graft?
• In the case of cervical corpectomy, should intermediate points
of fixation should be added to improve construct stability?

TYPES OF PLATES
Nonconstrained Plates
• First-generation plates are nonconstrained plates.
• Provide a weak interaction between the plate and the screw
heads.
• Types include Caspar plates and H plates.
• Screw backout is unrestricted in these models.

Static Plates
• Second-generation plates are constrained plates (static plates).
• Provide strong fixation between the plate surface and the screw heads.
• Examples include Synthes cervical spine locking plates (CSLPs), Orion
plates, and Atlantis plates.
• Screw backout is restricted in these models.
• The CSLP is an example of a second-generation anterior cervical plate and
was first introduced by Morscher with fixed-angle screws.
• Small set screws are placed into the main screw heads, widening the
screw head and locking the head to the plate.
• The CSLP variable-angle plate is a modification that allows up to 20
degrees of variability in the plate–screw angle.

Dynamic Plates
• Third-generation plates are semiconstrained plates (dynamic)
plates.
• Allow a variable amount of graft subsidence.
• Subsidence is observed during aging and after spine surgery
and is accepted as a naturally occurring process.
• Anterior cervical plates help to stabilize the spine, they also
constrict subsidence.

• An anterior plate that carries most of the axial load instead of
sharing it with the bone graft has a high rate of failure.
• Dynamic plates were developed to avoid the late
complications of rigid plates.
• Screw loosening and screw and plate fracture are more
common in cases of multilevel fusion with either a
corpectomy or ACDF grafts.
• The main reason is graft absorbtion resulting in subsidence.
• If the loss of graft height cannot be accommodated by the
plate–screw angle, the screw has increased risk of fracture.

• Bone density is another important factor that must be
considered during anterior cervical plating.
• If the bone is too dense, the screw will fracture instead of
rotating within its hole.
• If bone density is low, screw pullout is another failure mode
of anterior cervical constructs.

• Through a better understanding of the biology of bone
healing, plates now exist that allow stronger and quicker
fusion with lower failure rates while still achieving the
additional goals of restoration or preservation of lordosis and
protection of neural elements.

• Dynamic plates now restrict screw back out
• Also allow some variability in translational and rotational
movements.
• There are two main two kinds of dynamic anterior cervical plates
manufactured by the spinal device companies, rotational and
translational.
• In the semiconstrained rotational design, variable-angle screw
systems allow the screws to toggle inside the bone.
• This rotational movement can also lead to instrumentation failure .
Examples include anterior cervical plates from Codman, Blackstone,
Acufix, Zephir, and Atlantis (hybrid and variable).
• The semiconstrained translational design allows translational
motion that is provided by the plate–screw interface. Examples
include the ABC plate, DOC system, and Premier plate.

• Dynamic implants allow natural subsidence to occur while
effectively stabilizing the spine by preventing excessive
movements in translation and rotation.
• Load sharing helps improve normal bone healing, resulting in
earlier fusion.
• Decreased rates of construct failure have been reported with
dynamic implants

Advantages of Anterior cervical plates
• Augment stabilization, enhancing the likelihood of a solid
fusion.
• Resist kyphosis.
• Reduce the need for external bracing or halo vest placement,
and they allow mobilization of the adjacent spinal segments.
• Reduce the risk of graft extrusion.
• Reduce the rate of nonunion
• Nonunion rates range from 11% to 63% in multilevel
interbody fusion cases and from 25% to 45% in corpectomy
and strut graft applications.

• Based on these advantages, anterior plating has
become the standard treatment for one-level
cervical discectomy procedures in order to avoid
complications of graft collapse and loss of
lordosis.
• If a cervical kyphosis is not severe, an anterior
plate can also be used to reduce it.
• This is achieved by spreading the disc space with
a vertebral body spreader, followed by lordotic
graft and plate placement

Disadvantages
• Increases the cost of surgery.
• Require special instruments and training for application.
• Plate-specific complications can occur, such as screw loosening
or fracture, infection, and neural injury.

INDICATIONS
• Cervical spine trauma with anterior column injury
• Cases of cervical spondylotic myelopathy requiring anterior
decompression via ACDF
• After cervical corpectomy
• In anterior surgery in patients who have been previously
treated with a cervical laminectomy
• Following decompression and stabilization of cervical spine
tumors involving the anterior column
• In post-laminectomy kyphosis following anterior
decompression

• In the case of plating following cervical corpectomy, vertebral
body reconstruction can be performed using bone autograft
or allograft, polymethyl methacrylate, or nonexpandable or
expandable cages.

Contraindications for anterior cervical
plating
• Severe osteoporosis
• Osteomyelitis or
• Discitis.

Anterior cervical disectomy and fusion

PLATE PLACEMENT
• To enhance fusion and improve outcomes, the following
general rules should be followed in to achieve better plate
fixation.
• Screw lengths can range from 14 to 22 mm.
• Using longer screws theoretically increases screw pullout
strength, especially when bicortical screw purchase is
achieved.
• This must be weighed critically against the increased risk of
cerebrospinal fluid (CSF) leak or spinal cord injury.

• Unicortical screws are more commonly used and do not
penetrate the posterior cortex.
• They are biomechanically weaker than their bicortical
counterparts, they are much safer to place and do not require
lateral fluoroscopy for guidance.
• An example of unicortical screws are Morsche screws, and
their standard length is 14 mm.
• Rather than using a perpendicular screw trajectory in relation
to the vertebral body surface, anterior plating screws should
be placed at an angle in order to increase the strength of
screw back out.

• Cranial and caudal angulation (approximately 12 to 15
degrees) provides a stronger construct.
• Convergent screws (medially angulated screws at
approximately 6 degrees in relation to midline) also provide
extra strength.
• Divergent screws (lateral angulation) might provide similar
strength, they are not as widely accepted owing to the risk of
nerve root injury .
• Prebent or lordotic plates help protect against screw
loosening. However, overbending of the plate should be
avoided to avoid implant fatigue.

• Placing a graft in compression increases the rate of bony union.
• Protecting the cortical end plate’s integrity during discetomy will
limit telescoping of the graft into the adjacent vertebral body.
• Increasing the surface area of the plate also helps increase the rate
of bony union.
• Removing all soft tissue from the fusion site can decrease the
likelihood of nonunion.
• Irrigation during drilling should be used to avoid thermal injury.
• The anterior plating screws must not be overtightened because this
can cause damage and subsequent loosening within the screw hole.
• Satisfactory tightening of each screw results in a better bone
purchase.

COMPLICATIONS
• Intraoperative complications of anterior cervical plating are quite
rare.
• Most complications, such as recurrent nerve palsy and
postoperative hematoma, are generalizable to anterior cervical
surgery and should not be directly attributed to cervical plates.
• Difficulty in swallowing, increased in incidence with anterior
cervical plate application.
• Esophageal perforation related to plate or screw erosion has also
been reported.
• Wound infection does not appear to be more common with the use
of plates.
• If osteomyelitis or wound infection develops, it may be necessary
to remove the plate.

• Bicortical screws can cause an iatrogenic spinal cord or dural injury.
• If proper screw lengths and lateral fluoroscopy are used, the probability is
decreased.
• Most surgeons prefer screw lengths that do not cross the posterior cortex.
• If the graft is too tall, the resulting increase in lordosis and apposition of
the facet joints can lead to axial neck pain.
• The neural foramen can also narrow, leading to nerve root compression.
• Ideally, the goal of surgery should be to increase the disc height not more
than 2 mm.
• If the presurgical disc height was severely collapsed, then an interbody
graft that is 3 to 4 mm higher than preoperatively may be acceptable.
• Alternatively, if disc height was normal prior to surgery, a 1 mm increase in
interbody height should be sufficient.

• Screw loosening and backout are the most common
complications of cervical plating.
• Traynelis has reported a 3.5% incidence of such complications.
• Minimal screw loosening requires close radiologic follow-up.
• Significant screw back out, however, can require removal of
the screw owing to the risk of perforating the esophagus.
• The most common causes of screw loosening are placement
into the disc space or into osteoporotic bone.
• Screw breakage and plate fracture are occasional
complications of anterior cervical plating.

• The posterior approach to cervical spine instrumentation was
pioneered by B. E. Hadra in 1891
• When he wrapped loops of silver wire around the spinous
processes of the cervical spine for stabilization.
• Hadra treated chronic fractures, kyphotic deformities, and
Pott’s disease with this technique.
• Fusion of the cervical spine was first described in 1911 by
Hibbs and Albee in independent publications.

INDICATIONS
• The goal of posterior cervical spine instrumentation is to
restore anatomic alignment
• Provide immediate stability
• Promote fusion
• Prevent neurological compromise
• Allow early mobilization of the patient
• Cervical instability is the primary indication for posterior
instrumentation of the subaxial cervical spine

• Instability has been defined as loss of the ability of the
spine, under physiologic loading, to maintain its
displacement pattern and prevent increased deformity or
neurological deficit (or both).
• Injury to or destruction of the bony structures or ligaments
may introduce instability.
• Also includes anatomic alterations that occur as a result of
operative decompression. Such alterations and their resultant
effects on stability must be taken into account when the
placement of instrumentation is considered.
• Frequently, fusion and instrumentation are indicated
preemptively to treat anticipated postoperative instability or
to prevent anticipated postoperative deformity.

• The choice of anterior, posterior, or combined
anteroposterior instrumentation is based on the clinical
scenario and surgeon’s experience.
• In general, the anterior and middle columns must be
capable of weight bearing for posterior instrumentation to
be used alone
• Likewise, posterior instrumentation alone is generally less
desirable in the presence of a significant kyphotic deformity
of the cervical spine.
• Although restoration of sagittal alignment can occasionally
be accomplished from a posterior approach, the surgeon
should consider using an anterior approach or a combined
approach in such instances

ANATOMY/EXPOSURE
• Dissection should begin in the midline over the level of
intended fusion and continue through the nuchal fascia; the
surgeon must be careful to stay in the relatively avascular
midline raphe.
• Subperiosteal dissection of the spinous processes, laminae,
facets, and lateral masses to their lateral edges should be
performed.
• Interspinous ligaments should be left intact when possible, as
should the muscular attachments and nuchal ligament to C2.
It has been suggested that exposure of the C7 transverse
processes aids in identification of the entry point for
placement of pedicle screws.

• The nerve root exits the neural foramen at the ventrolateral aspect
of the superior facet.
• Viewed from a posterior exposure, the nerve root is located at the
level of the articular line.
• The vertebral arteries are directly ventral to the depression formed
between the dorsal surface of the lateral mass and the lamina.
• The pedicle forms a bridge from the dorsolateral portion of the
vertebral body to the ventromedial aspect of the lateral mass,
midway between the superior and inferior articular surfaces.
• The mean mediolateral pedicle angle, measured from the midline
sagittal plane, ranges from 39 degrees at C2 to a maximum of 48
degrees at C4 and C5. The mean width of the pedicle measured
from the outer cortices ranges from 4.8 mm at C3 to 6.9 mm at C7.

• Fluoroscopy or plain radiography is vital to identify the correct
level of instrumentation.
• The use of intraoperative aids, including fluoroscopy or
neuronavigation, although not essential, may greatly facilitate
safe posterior instrumentation.

• The bony posterior elements that are available to anchor
instrumentation include the spinous processes, laminae,
facets, and lateral masses, depending on the patient’s
anatomy and the pathologic condition.
• The pedicles are also available for instrumentation, although
the small diameters of the C3, C4, and C5 pedicles frequently
preclude safe screw placement.
• The individual patient’s disease process, the suitability of the
bony structures to accept hardware, the biomechanics of each
construct, and the surgeon’s experience should be considered
when the method of instrumentation is selected

Stabilization Techniques: Lower
Cervical Spine
Interspinous Wiring
• Limitations include the necessity of having intact posterior
elements for fixation and the occasional necessity of
incorporating uninjured segments into the construct for
adequate stabilization.
• Osteopenic bone
• Multistranded cables made of stainless steel, titanium, or
polyethylene are biomechanically superior to monofilament
stainless steel in their ability to resist fatigue.
• Monofilament wire is tightened and secured by twisting
• Cable is tensioned and crimped according to the
manufacturer’s recommendations.

Posterior Techniques
• Wiring Technique
• The most simple and least dangerous is interspinous wiring
Principle
• This technique applies the tension band principle.

Advantages
• Relatively easy.
• Safe.
• Large surface area for fusion.
• Short segment stabilization.
Disadvantages
• Wire breakage.
• Wire cut-out.
• Cannot be used in fractures of the vertebral arch including
the spinous processes.
• Poor biomechanical fixation - especially in rotation.
• Failure to maintain lordosis

Surgical Technique
• A midline posterior approach is used.
• Identify radiographically the levels to be fused.
• A hole is drilled on each side of the base of the spinous process of
the upper vertebra of the injured segment
• The entry point corresponds to the junction of the base of the
spinous process and the lamina.
• A towel clip is placed in the holes, and with a gently rocking
movement the holes are connected
• A 1.2-mm wire is passed through the hole and then around the
base of the inferior spinous processes, leaving the interspinous soft
tissue intact
• The two ends of the wires are tightened.
• Lastly, the wire ends are curved around the inferior spinous process
and twisted tight.
• The laminae are decorticated with a high-speed burr, and the
cancellous bone graft is applied .

Rogers’s Technique
• Rogers’s technique may be used for injuries to the posterior
ligamentous complex or facet capsule, or both, in the absence
of bony injury.

Fig. 6.1 Interspinous wiring of the lower cervical spine
a A hole is made on each side of the base of the spinous process of the upper vertebra of the injured segment, using a drill.b The two tips of a towel clamp
are placed in the holes, and with a gentle rocking movement the holes are connected
c A 1.2-mm wire is passed through the hole and then around the base of the inferior spinous process, leaving the interspinous soft tissues intact. d The
two ends of the wire are tightened, curved around the inferior spinous process and twisted tight .e The lamina are decorticated and cancellous bone graft
is applied

Bohlman’s Triple-Wiring Technique
• Bohlman’s triple-wiring technique was developed as an
evolution of Rogers’s interspinous wiring technique to impart
greater biomechanical stability.
• First, Rogers’s interspinous wiring is performed.
• Then two additional wires are passed through the spinous
processes and looped around each respective spinous
process, if space allows.
• Each cable is next passed through corresponding holes in two
corticocancellous autologous bone grafts placed on either
side of the spinous processes.
• The ends of each wire or cable are then secured under
tension

Bohlman’s triple-wiring technique. After Rogers’s interspinous wiring is
performed, two additional wires are used to affix corticocancellous bone
grafts firmly along the spinous processes.

Dewar’s Technique
• Another variation of interspinous wiring is Dewar’s procedure (or
tension band configuration).
• Two corticocancellous strips of bone are placed on the lateral
surfaces of the spinous processes and medial laminae of the
vertebrae to be fused.
• Threaded Kirschner wires (K-wires) are introduced percutaneously
to affix the bone grafts to the spinous processes and cut with 1 cm
of overhang laterally.
• Wire is threaded around the K-wires in a Gallie-type manner.
Cervical flexion therefore causes medially directed pressure on the
bone graft.
• The posterior elements must be intact in order to use this
technique.

Facet Wiring
• Facet wiring, originally described by Robinson and Southwick
• May be used for unilateral or bilateral facet dislocations or in
cases in which the posterior neural arch is damaged or
surgically removed.
• Holes are drilled in the inferior facet processes at a 90-degree
angle relative to the articular surface while the superior facet
processes are protected with a Penfield dissector. Wire or
cable is then passed through each hole and tightened around
longitudinal strut grafts for fusion

Facet wiring technique. After holes are drilled in the inferior facet processes,
wires are used to affix longitudinal strut grafts to the dorsal surface of the lateral
masses

Cahill’s technique
• For improved stiffness in axial rotation, Cahill and colleagues
introduced a technique wherein the facets are secured to the
spinous processes.
• The inferior facet processes are drilled in a manner similar to
that described by Robinson and Southwick, and wire or cable
is passed from the facet to the spinous process of the next
caudal level.
• Wire or cable is then wrapped around the spinous process or
looped through a hole drilled at the base of the spinous
process of the caudal vertebra.
• This technique improves stiffness in axial rotation over both
interspinous wiring and Robinson and Southwick’s facet wiring
technique.

Cahill’s oblique wiring technique. Wires or cables are passed through holes in
the inferior facet processes and secured to the spinous process of the level
below. The wire or cable may be looped around or through the base of the
spinous process

Sublaminar Wiring (Cabling)
Techniques
• Braided cable is the preferred material to use for passing wire into
the neural canal because of its increased flexibility and lesser
likelihood of being passed anteriorly into the spinal canal.
• Braided cable may be doubled over on itself and the blunt end
passed more safely beneath the laminae. After bilateral cable
placement, a bone graft is placed in the interspinous space or along
the laminar surface, and the cable is tightly secured by crimping.
• Placement of sublaminar wires or cables is associated with a 7% risk
of neural injury.
• Sublaminar cables may be used as fixation points for segmental
instrumentation.

Luque rectangle
• The prototypical device is the Luque rectangle.
• This is a variant of Robinson and Southwick’s facet wiring and
consists of a metal rod in the shape of a rectangle that is
affixed to the facets in a manner similar to Robinson and
Southwick’s facet wiring technique.
• Sublaminar wires are then placed one level cephalad and one
level caudal to the levels of fusion and tightened to the
horizontal portion of the metal rod. In comparison with
Robinson and Southwick’s facet wiring technique, this method
has improved biomechanical stiffness and decreased range of
motion.
• It may be used after surgical decompression with
laminectomies that span multiple levels

Lateral Mass Screw Fixation
• Placement of screws in the lateral mass was first described by Roy-Camille
and associates in 1964
• Potential for neurovascular injury exists because of the proximity of the
vertebral artery and cervical nerve root.
• Patients’ anatomy must be studied carefully, especially in those with
severe degenerative disease, in whom erosive arthropathy may reduce
the size and distort the shape of the lateral masses considerably.
• Useful in cases in which the spinous processes and laminae are
compromised or absent and fixation of the posterior neural arch is not
possible with interspinous wiring or other techniques.

• The boundaries of the dorsal surface of the lateral mass serve as a guide
to the screw entry point.
• Boundaries are the lateral facet edge, the medial facet line, and the
articular lines cranially and caudally.
• The Roy-Camille method begins with an entry point at the center of the
lateral mass.
• The screw is placed with 10 degrees of lateral angulation and 0 degrees of
cephalad angulation
• In the Magerl technique, the entry point is 2 to 3 mm medial and
cephalad to the midpoint of the lateral mass. The screw is placed with 25
degrees of lateral angulation and a cephalad angulation that is parallel to
the articular surface of the facet joint

Insertion of screws in the lateral mass (orientation is cranial toward the left of
the illustration). For the foreground screw, note that there is 0 degrees of
cephalad angulation and 10 degrees of lateral angulation in the Roy-Camille
lateral mass screw technique. For the background screw, note that the lateral
mass screw is placed with a cephalad angulation parallel to the facet joint
and a lateral angulation of 25 degrees in Magerl’s technique.

• An and coauthors described a modified
technique in which the entry point is 1 mm
medial to the midpoint of the lateral mass.
• The screw is placed with 30 degrees of lateral
angulation and 15 degrees of cephalad
angulation.
• These differences lead to unique risks to the
neurovascular structures.

• Heller and coworkers conducted a study of the trajectories of
screws placed with the Magerl and Roy-Camille techniques and
found that the rate of injured nerve roots was 2% with the Roy-
Camille technique, as opposed to 6% with the Magerl technique.
• The Roy-Camille technique resulted in a 34% rate of facet joint
violation, whereas the Magerl technique resulted in a 0% rate.
• Kim and colleagues published their results of free-hand placement
of lateral mass screws in the subaxial cervical spine. They selected
an entry point 2 mm medial to the center point of the lateral mass
and a planned lateral angulation of 30 degrees. Violation of the
transverse foramen and of the facet was noted in 0.876% and
1.433% of screws, respectively, with no violation of the
intervertebral foramen or damage to the vertebral artery

• Lateral mass screws ranging in diameter from 2.7 to 4.5 mm
may be used.
• Screws smaller than 3.2 mm in diameter or larger than 3.5
mm in diameter have lower pullout resistance than do screws
with diameters within this range.
• The Magerl technique is associated with higher resistance to
pullout, probably because of the ability of the screw to
engage a greater length of bone in the lateral mass.
• Screw length may be 10 to 16 mm
• 14-mm screws achieve bicortical purchase in approximately
92% of lateral masses, as reported by Sekhon.

• Fusions supplemented with lateral mass screws and rods or
plates are associated with an overall fusion rate of 80% to
97%.
• This percentage varies with the indication for fusion.
• Sekhon reported a 1.4% rate of instrumentation failure and a
2.1% rate of kyphosis after a mean follow-up period of 22
months. In a series of 221 patients, Roy-Camille and
associates7 reported 85% without secondary kyphosis, 8.8%
with 5 degrees of kyphosis, 3% with 5 to 10 degrees of
kyphosis, and 3% with 10 to 20 degrees of kyphosis

• Failure of lateral mass screw–based instrumentation occurs most
commonly at the bone-screw interface.
• The pullout resistance is highest at C4, with strength decreasing about
30% at C2 and C7 because of anatomic variability of the lateral masses.
• This underscores the need to consider each potential site of fixation
carefully in terms of suitability for screw placement.
• Bicortical purchase of lateral mass screws offers 28% increased resistance
to pullout over unicortical purchase.
• Some authors have suggested that bicortical purchase may be dangerous
because of the proximity of the nerve root and vertebral artery.
• However, the risk for nerve root injury and vertebral artery injury varies
according to the technique used for screw placement.

Transpedicular Screws
• The technique of transpedicular screw placement in the cervical
spine was first described by Abumi and colleagues in 1994.
• Other than at C7, its use is not currently widespread.
• Insertion is technically more difficult and associated with more
potential risks to neurovascular structures than is insertion of
lateral mass screws.
• Indications include deformity or instability in patients with poor
bone quality, particularly those with osteopenia or rheumatoid
arthritis and especially if instrumentation spanning several
segments is needed.
• A relative indication for its use is posterior correction of kyphosis
and deformity, for which transpedicular screws offer enhanced
biomechanical stability and resistance to pullout.

• The insertion point for cervical transpedicular screws at C3 to
C6 has been described as slightly lateral to midline of the
posterior surface of the lateral mass and just inferior to the
articular line.
• A high-speed bur is used to create the screw entry point,
followed by insertion of a pedicle probe under fluoroscopic
guidance.
• The suggested trajectory is 25 to 45 degrees medially in the
axial plane and parallel to the superior end plate in the
sagittal plane.
• A second technique that involves partial drilling of the medial
cortex of the cervical pedicle has been described43 but not
widely used.

• Transpedicular screws are placed more frequently at C7 for a variety of
reasons.
• Because the lateral masses of C7 are often unsuitable for placement of
lateral mass screws, C7 transpedicular screws are a useful alternative as
caudal anchors for longer constructs.
• Second, pullout of lateral mass screws at C7 is more likely when at either
the cephalad or caudal end of a construct.
• Finally, placement of transpedicular screws is technically less demanding
in C7 than in other subaxial cervical vertebrae because the C7 pedicles
have a larger mean diameter (5.4 to 9.1 mm) and are relatively remote
from the vertebral arteries in the majority of patients.
• The screw entry point for C7 is halfway between the medial facet line and
the lateral facet edge in the mediolateral dimension and 1 mm inferior to
a horizontal line that bisects the base of the transverse process in the
craniocaudal dimension

• It has been suggested that for C7 transpedicular screw placement, the
base of the transverse processes should be exposed.
• Alternatively, a limited laminectomy may be performed to palpate the C7
pedicle to aid in accurate screw placement.
• Once the proper entry point has been located, the cortical surface is
perforated with a bur to a depth of 5 mm.
• The pedicle is then cannulated to an appropriate depth at a medial
angulation of 35 to 45 degrees and a caudal angulation of 5 degrees from
the inferior end plate of C7.
• Some authors have suggested that the medial pedicle cortex is stronger
than the lateral pedicle cortex and that the medial wall should thus be
used as a guide to cannulation of the pedicle

• Cervical transpedicular screw insertion is generally safe, according to
studies by experienced groups.
• In both in vivo and in vitro studies, C4 is found to be the most frequently
violated pedicle.
• Abumi and colleagues reported that 712 cervical pedicle screws were
inserted in 180 patients, with 45 (6.3%) pedicle violations seen on
computed tomographic (CT) scans.
• There were three neurovascular complications: of the 45 pedicle
violations, caused radiculopathy, and a vertebral artery injury occurred
without any reported neurological consequence.
• Screw size in this study was 3.5 to 4.5 mm in diameter and 20 to 28 mm in
length. Preoperative CT evaluation of individual pedicle anatomy is
suggested for each patient.

Laminar Screws
• Laminar screws are another safe alternative for fixation within the
cervicothoracic spine.
• The benefits of this technique include relative ease of placement and
avoidance of the neurovascular structures.
• Each patient’s anatomy must be assessed accordingly. In some
circumstances, thin-slice CT scans can assist significantly in determining
the necessary measurements of the individual cervical lamina.
• This technique has been utilized at all levels of the subaxial spine,
although C2 and the upper thoracic levels are more commonly selected
because of the robust lamina usually found at these levels.
• In addition, biomechanical testing of a finite element model in which C2
laminar and pedicle screws were compared in an atlantoaxial fusion model
demonstrated similar biomechanical properties with regard to rigidity and
von Mises stresses

Laminar Hooks
• Laminar hooks may be used as an alternative point of fixation in the
posterior cervical spine.
• Placement is technically simple, but posterior elements must be intact,
and it does expose the patient to risk for neural injury because of the
presence of the hook in the spinal canal.
• Cervical hooks, when placed at the caudal end of a lateral mass screw
construct or an atlantoaxial posterior construct, result in similar resistance
to flexion-extension, lateral bending, and axial rotation ranges of motion
as do bicortical lateral mass screws or pedicle screws.
• Hooks have higher resistance to pullout than do either lateral mass or
transpedicular screws if placed properly.
• Therefore, cervical laminar hooks are potentially useful in an alternative
method of fixation, particularly in situations in which lateral mass screws,
translaminar screws, and transpedicular screws are precluded

STASCIS
Surgical timing in acute spinal
cord injury study

INTRODUCTION
• To search for emerging approaches for surgical management
of SCI
• NASCIS 2 – failed study
• SYGEN – ( phase 3 RCT) – largest study,
• SYGEN- evaluating GM-1 ganglioside complex in SCI
• Neuroprotective,interim analysis at 3 month- improving
neurological status
• 6 month-failed response
• SURGICAL THERAPY--> 1. Decompress the spine- prevent
spinal cord compression and neurological damage
2. Realign spinal column and restore stability

• SCI injury – primary- due to direct effect of trauma
Secondary- ischemia,edema,free radical,cellular
ionic imbalance,release of excitogenic glutamate,vascular
phenomenon (vasospasm,reperfusion injury)
Surgeons role– to prevent the secondary injury
Cord compression- form of secondary injury
Degree of neural damage- directly proportional to duration of
cord compression
Inversely related to time elapsed from
injury to surgical decompression

• FEASIBILITY STUDY OF SURGICAL TIMING
• Traumatic SCI pt who underwent surgery
• TORONTO TEAM- 24% within 24 hours , 40% by 48 hours
• European team- 51% with in 24 hours
• IDEAL CUT OFF TIME– surgery providing max neuroprotective
• TWO CUT OFFS – 24 hour, 72 hours

International consensus
• Fehling et al..SURVEY STUDY
• ORTHO SPINE SURGEON and NEURO SPINE SURGEON
• Case based questions regarding optimal surgical management
of traumatic SCI with evidence of ongoing spinal cord
compression
• 80% prefers to decompress with in 24 hours except for central
cord syndrome
• Also, incomplete SCI – prefers to decompress with in 6 hours

• Sagittal CT/ T 1W MRI- most effective in evaluating spinal
canal compromise
• Sagittal T2 MRI- MOST effective in evaluating cord
compromise

Classification system for spinal trauma
• STSG- spinal trauma study group
• 50 surgeons from 12 countries
• 2 novel classifications
• 1st- SLIC ( sub axial injury classification for cervical spine)
• 2nd- TLICS- thoracolumbar injury classification and severity
score
• Score – if less than 4 – non operative approach
More than 4 – with or without surgery

METHODS
• Multi centre,cohort study
• Aug 2002- sept 2009
• Study published on 23 February 2012
• 6 hospitals (USA,CANADA)
• Early vs late
• Follow up period – 6 months
• NASCIS/ SYGEN TRIAL/ NATURAL HISTORY
TRIAL- found out that vast majority of
neurological recovery occurs during this period.

PRESENTATIONS
• ASIA
• AMS- ASIA motor score
• ASS- ASIA sensory score
• AIS- overall ASIA impairment score
• Additional information- CCI ( Charleson
comorbidity score) ,
• GCS
• Age/ gender/ mechanism of injury

• Plain X Ray
• CT scan
• MRI cervical spine
• CT myelography if MRI not possible
• Spinal cord compression in MRI cervical spine is a major
criteria
• Methyl prednisolone given to all patients presented with in 8
hours according to NASCIS
• Medical treatment given to all

• American association of neurological surgeon cervical SCI
guidelines– permissive or induced hypertensive therapy (
mean BP > 85 mm hg)
• POST OP CT scan--> with in 72 hours of surgery for all
patients and read by site specific radiologist .
• REPEAT MRI- if neurological deterioration
• Finally– Rehabilitation programs tailored for each pt
• X-ray/ct scan- u/l or b/l locked facets – open or closed
reduction ,and post procedure MRI in case of closed
reduction.
• Resolution of cord compression- closed reduction timing
recorded as Time of decompression

• Early surgery
• Late surgery
• Specifics of surgical intervention discussed
• Direction of Approach discussed on discretion of
treating surgeon
• Anterior vs posterior
• Number of level decompression
• ALL CASES --- decompression was accompanied
with assisted instrumented fusion procedure.

• After surgery – pt were analyzed in groups according to timing
of their surgical intervention
• TRAINED RESEARCH ASSISTANT– blinded to the timing of pt
surgical treatment ,performed follow up
• Follow up neurological exam done at the time of discharge
and 6 month post op
• Relevant postop complications documentation were also done

Statistical analysis
• All analysis performed using SAS 9.2
• Generalized Ordinal regression analysis done to determine
the the effects of surgical timing on AIS grade improvement
and to account for base line discrepancies b/w cohorts
• Dependent variable-ordinal change in AIS grade from baseline
preop to 6 month post op
• Independent variable- surgical timing ( early vs late)
• Predictor variable- related to baseline patient

RESULTS
• Mean time to surgery – early group 14.2+_5.4 hours
• Late group 48.3+_29.3 hours
P value < 0.01
No pt in either group underwent repeat operation for
inadequate decompression as determined by post op imaging

Neurological recovery at 6 months
• Entire study group – degree of neurological improvement was
significant , p value =0.02
• Early group- 56(42.7%)- no improvement, 48(36.6%) grade 1,
22(16.8%) grade2, 4(3.1%) grade 3 improvement and 1(0.8%)
had grade 1 worsening
• Late group 46 (50.6%) no improvement, 37 (40.7%) grade 1 , 8
(8.8%) grade 2 improvement and no pt worsened
• Grade 1 improvement– early vs late group,OR 1.33
• Grade 2 improvement– early vs late ,OR 2.57

DISCUSSION
• STASCIS– largest prospective multi center study comparing
early vs late surgical decompression in setting of acute SCI
• RESULTS of unadjusted analysts- significant difference favoring
early group in the proportion of at least 2 AIS grades at 6
month follow up
• SYGEN trial– largest therapeutic trial in SCI- defined significant
neurological recovery as at least 2 grade AIS IMPROVEMENT
at 6 month follow up
• Multi variate regression analysis adjusted for preop
neurological status and steroids administration continues to
favor early surgery

NASCIS
National acute spinal cord
injury study
Overview

Ppt is for academic purposes only and material is compiled from
various neuro books
References-
Youman
Various internmet articles and ppts
Various internet images
Other neurosurgical books
Thank you

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