Добавил:
Sekretar
kiopkiopkiop18@yandex.ru
t.me/Prokururor I Вовсе не секретарь, но почту проверяю
Опубликованный материал нарушает ваши авторские права? Сообщите нам.
Вуз:
Предмет:
Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_6028_Библиотеки_им_академика_М_И_Перельмана
.pdf
294 Spine Core Knowledge in Orthopaedics
Table 22–2: Methylprednisolone Dosing*
TIME FROM DOSE OF
INJURY METHYLPREDNISOLONE DURATION
<3 hours 5.4 mg/kg/hr 24 hours
3-8 hours 5.4 mg/kg/hr 48 hours
>8 hours No treatment No treatment
* All patients should receive an initial 30-mg/kg bolus followed by the listed dosage regimen.
Posterior Instrumentation
●
See Box 22–4 and Fig. 22–10.
Fracture Subtypes
●
Spinal injuries can be divided into several categories
Figure 22–7: A schematic of the three columns of the spine.
Middle AnteriorPosterior
based upon their biomechanical and anatomic
characteristics and the patient’s neurological status
(Table 22–6).
Compression Fractures
●
Of compression fractures, 85% are caused by primary
osteopenia.
●
In North America, $14.7 billion dollars are spent
annually as a result of medical complications associated
with compression fractures.
●
Potential indications for surgical intervention in
the setting of a compression fracture include the
following:
●
25-30˚ of initial kyphosis (significant posterior
osteoligamentous disruption)
●
>50% loss of anterior vertebral body height (potential
for significant posterior osteoligamentous disruption)
(Figs. 22–11 and 22–12)
Burst Fractures
●
Burst fractures involve disruption of the anterior and
middle spinal columns.
●
No definitive evidence correlates the degree of neural
impingement with the severity of neurological deficit
following a thoracolumbar burst fracture (Figs. 22–13
through 22–16).
Table 22–3: Diagnostic Imaging Modalities
IMAGING MODALITY ADVANTAGES DISADVANTAGES OTHER
Plain radiograph Inexpensive Quick Poor visualization of middle spinal column Assess posterior vertebral body
disruption and canal involvement line on lateral radiograph
(disruption suggestive of
burst fracture)
CT Excellent visualization of bony anatomy, Poor visualization of soft tissues
particularly the middle spinal column
Excellent assessment of spinal canal
shape and patency
MRI Excellent visualization of soft tissues Poor visualization of detailed bony anatomy Hematoma has decreased T2
including ligaments, disk, and spinal cord signal Adjacent edema
appears as an increased signal on a T2-weighted image.
Edema extending more than
two vertebral levels and the
presence of hematoma
within the spinal cord are
considered poor prognostic
signs
CHAPTER 22
Thoracic and Lumbar Spine Trauma 295
Table 22–4: Ferguson and Allen Classification System for Spinal Fractures
TYPE OF FRACTURE
COLUMN ANTERIOR MIDDLE POSTERIOR
Compressive flexion
Type I Compression None None
Type II Compression None Tension
Type III Compression Blown out* Tension
Distractive flexion Tension Tension Tension
Lateral flexion
Type I Unilateral compression Unilateral compression None
Type II Unilateral compression Unilateral compression Ipsilateral compression or contralateral
tension
Translational Shear Shear Shear
Torsional flexion Compression or rotation Disrupted Tension or rotations
Vertical compression Compression Bony compression Bony involvement
Distractive extension Tension Compression
* Blown out—Evidence of a middle column bone rotated into the neural canal between pedicles.
Box 22–2:
●
Denis defined instability as a disruption of two or more of the
Instability and Outcomes
three spinal columns.
●
Mechanical—Posterior osteoligamentous elements disrupted in
distraction with obvious kyphosis
●
Neurological—Neurological deficit in a setting of spinal
fracture
●
Combined
●
A study performed on patients with a cervical spinal cord injury
found no significant difference in functional neurological recovery
when patients were operated on either early (<3 days) or late
(>5 days) (Vaccaro et al. 1997).
●
No studies have found a direct correlation between the
percentage of canal occlusion radiographically and the severity of
neurological deficit following burst fractures (Gertzbein 1994).
●
Late decompression, even several years following injury, may
enhance neurological recovery of the spinal cord, the conus
medullaris, and the cauda equina.
Table 22–5: Surgical Approaches to Spinal Decompression
Distraction–Flexion Injuries
●
Specific variants are also known as seat belt injuries
(Chance fracture).This injury type may involve bone,
ligaments, or both (Figs. 22–17 and 22–18).
●
Bone-only injuries in children may be successfully
reduced in a closed fashion and immobilized in an
extension cast.
●
Surgery is often indicated in the presence of a soft tissue
variant of this injury regardless of the patient’s age.
Fracture Dislocations
●
These are often high-energy injuries and are frequently
associated with severe neurological compromise.
●
These injuries usually require a posterior or a
circumferential spinal stabilization procedure (Figs. 22–19
through 22–27).
Distraction–Extension Injuries
●
These are commonly referred to as lumberjack injuries.
APPROACH ADVANTAGES COMMENTS
Anterior Easier access to retropulsed vertebral bone and discal material Anterolateral approach—Transthoracic T4-T9, thoracoabdominal
T10-L1, retroperitoneal T12-L5
Direct visualization of compressed neural tissue Right-sided approach above T10 to avoid great vessels
Minimal manipulation of the spinal cord
Posterior Effective when using distractive instrumentation to reduce retropulsed Posterior indirect reduction through ligamentotaxis more efficient if
bone fragments done within 2-3 days of injury
Posterolateral Instrumentation without the need for a second anterior staged Access to the thecal sac through the pedicle
procedure Difficult anterior column reconstruction
Advantageous in lower lumbar fractures and lateralized nerve root Increased risk of neural injury secondary to neural manipulation
entrapment
296 Spine Core Knowledge in Orthopaedics
Box 22–3:
●
Interbody spacers inserted in an intracolumnar position act as
Interbody Grafts
load-sharing devices restoring axial stability until arthrodesis is
obtained.
●
The most commonly used interbody spacer is an autologous
tricortical iliac crest.
●
It has a faster rate of bony incorporation than allograft strut
grafts because of its biocompatibility.
●
An allograft strut graft is able to withstand greater physiologic
loads than an autologous iliac crest in the erect spine in the early
reconstruction and healing period (White et al. 1978).
●
Allograft sources such as a tibial shaft, femoral shaft, or
metallic mesh cages are gaining popularity.
●
There is a high association with metabolic bone disease
and a preexisting spinal deformity.
●
Ankylosing spondylitis
●
Diffuse idiopathic skeletal hyperostosis (Figs. 22–24
through 22–27)
Conclusions
●
Despite the advancements in spinal implants and
radiographic imaging, controversy continues to exist over
the indications for surgical intervention, the timing of
such intervention, and the approach with which to
correct any existing spinal deformity.
●
The basic tenets of trauma surgery should be strictly
adhered to in the management of thoracolumbar spine
trauma.
●
Once the patient is medically stabilized, a detailed
neurological examination and a careful radiographic
evaluation should be performed.
●
The surgeon should be aware of the biomechanics
of the thoracolumbar spine, the mechanism of
injury, and the various implants available for
treatment.
●
Most thoracolumbar injuries, in the absence of a
neurological deficit, are stable and can be treated
successfully nonoperatively.
●
For the rare unstable spinal fracture, with or without a
neurological deficit, surgical treatment is often beneficial
in improving patient mobilization and an early functional
return to society.
●
The goals in managing thoracolumbar injuries are to
maximize neurological recovery and to expeditiously
stabilize the spine for early rehabilitation and an early
return to a productive lifestyle.
AB
CD
Text continued on p. 303
Figure 22–8: An illustration of the technique
for anterior spinal instrumentation following
corpectomy. A, Insertion of vertebral body
screws. B. Use of vertebral body screws to
distract corpectomy site. C, Placement of
anterior vertebral body plate. D, Compression
of graft through the vertebral body screws. E,
F, Securing the plate with addition vertebral
body
EF
CHAPTER 22 Thoracic and Lumbar Spine Trauma 297
Box 22–4:
●
Biomechanically, a longer application of a longitudinal
Fixation
component (rod) reduces the risk of terminal implant cutout or
dislodgement.
●
However, this may contribute to increased global spinal
stiffness and subsequent junctional degeneration.
●
Shortcomings of distraction rod–hook techniques for fracture
reduction and stabilization include the following:
●
Hook dislodgement
●
Overdistraction, possibly leading to iatrogenic loss of lumbar
lordosis (flatback deformity) or excessive thoracic kyphosis
●
Pedicle screw anchors provide three-column bony fixation.
●
They allow potentially shorter posterior fixation lengths yet
confer adequate spinal stability (Lim et al. 1997).
●
The best candidates for posterior short-segment pedicle screw
fixation (one level above and one level below the fracture level)
are as follows:
●
Flexion–distraction injuries
●
Lower lumbar burst fractures in which the weight bearing line
is posterior to the posterior vertebral body wall
Figure 22–9: A postoperative lateral radiograph following the
completion of an anterior thoracolumbar decompression and a
stabilization procedure using a titanium mesh cage and an
anterior thoracolumbar plate.
Figure 22–10: Schematic of pedicle screw insertion sites and
placement of pedicle screws within the vertebral body.
298 Spine Core Knowledge in Orthopaedics
Table 22–6: Management of Thoracolumbar Fractures
TYPE NONSURGICAL MANAGEMENT SURGICAL INDICATIONS OTHER
Minor injuries TLSO At follow-up obtain flexion or extension plain Transverse, spinous, or articular process
x-ray films to rule out occult instability fractures
Fracture below L3—Add unilateral thigh
extension
Compression fractures Extension TLSO cast or orthosis >20-30˚ of initial kyphosis (significant posterior Nonsegmental hook–rod construct
osteoligamentous disruption) applying distraction–lordosis force vec-
tors for reduction
Early ambulation >50% loss of anterior vertebral body height Short segment pedicle screw construct
If fracture proximal to T7—add a cervical followed by immobilization in a
extension to brace or cast custom-molded hyperextension
orthosis or body cast for a minimum of
3 months
Recent reports of percutaneous cement
augmentation in symptomatic
osteopenic compression fractures (ver-
tebroplasty with or without balloon
elevation of the vertebral endplates)*
Burst fracture Bed rest until resolution of constitutional Neurologically intact No definitive evidence that correlates the
symptoms Progressive ambulation in a Kyphosis > 20˚ degree of neural impingement with
full contact orthosis or cast for 12-24 Facet subluxation or spreading of the the severity of neurologic deficit
weeks with or without a unilateral interspinous process distance following thoracolumbar trauma
thigh extension (fracture L3 or lower) >50% loss of anterior vertebral body
for the initial 6 weeks of treatment height
Neurologically compromised
Surgical decompression with imaging
documentation of significant neural
compression
Distraction–flexion Rarely indicated in an adult patient because Posterior compression force vector to reduce Anterior longitudinal ligament serves as a
injury of the unpredictable nature of healing the injury deformity; take care not to cause tension band with this injury
of this injury subtype iatrogenic retropulsion of bone or discal Look for associated intra-abdominal viscus
material into the canal injury with this injury mechanism
Fracture dislocations Rarely indicated because of the significant Posterior facet fracture dislocation, rotational Awake intubation may minimize
degree of instability and deformity instability, or a translational shear injury in neurologic injury associated with
associated with this injury subtype the absence of a neurological deficit, positioning
requiring an initial posterior segmental
reduction and stabilization procedure before
considering the need for an anterior
decompressive and stabilization procedure
Distraction–extension Consider an attempt to reproduce the Consider initial surgical stabilization with High association with metabolic bone
injury preinjury sagittal profile of the patient segmental internal fixation initially disease and a preexisting spinal
regardless of neurological status through through a posterior approach deformity (e.g., ankylosing spondylitis
bedding supplements or skeletal traction Consider a staged anterior stabilization and diffuse idiopathic skeletal
procedure if a significant anterior hyperostosis)
column defect is present
* (Verlaan et al. 2002.)
TSLO,
thoracolumbosacral orthosis.
§
CHAPTER 22 Thoracic and Lumbar Spine Trauma 299
BA
Figure 22–11: Flexion forces cause anterior compression of
the vertebral bodies and disks and tension in the posterior
elements.
DC
Figure 22–12: Denis classification of thoracolumbar
compression injuries. These fractures may involve both
endplates (A, type A), the superior endplate only (B, type B),
the inferior endplate only (C, type C), or a buckling of the
anterior cortex with both endplates intact (D, type D).
A
BC
Figure 22–13: Axial compression forces across the straight
thoracolumbar region result in pure compressive loading of the
vertebral body, most often resulting in a thoracolumbar burst
fracture.
DE
Figure 22–14: Denis classification of thoracolumbar burst
fractures. A-C
endplates, the superior endplate, and the inferior endplate,
respectively. D, A type D fracture is a type A burst fracture
with rotation, which is best appreciated on an anteroposterior
radiograph. The superior endplate, inferior endplate, or both
may be involved with this fracture.
, Types A, B, and C represent fractures of both
Figure 22–15: An axial CT image of a T12 burst fracture
demonstrating middle column failure with approximately 30%
canal occlusion.
Figure 22–17: A postoperative anteroposterior radiograph
following an anterior L1 corpectomy and fusion using a
titanium Harms mesh cage and an anterior plate and screw
construct.
Figure 22–16: A sagittal MRI of a 34-year-old male who
sustained a burst fracture to the T12 vertebral body.
Note the retropulsion of the posterior vertebral body with
compression of the anterior thecal sac.
Figure 22–18: Flexion–distraction forces across the
thoracolumbar spine frequently produce the typical seat belt
injury.
AB
CD
Figure 22–19: Denis classification of flexion–distraction
injuries. These may occur at one level through the bone (A),
at one level through the ligaments and disk (B), at two levels
with the middle column injured through the bone (C), or at
two levels with the middle column injured through the
ligament and disk (D).
CHAPTER 22 Thoracic and Lumbar Spine Trauma 301
A
ab
B
abc
C
ab
Figure 22–21: Denis classification of fracture dislocations.
These may occur at one lev
level through the ligaments and disk (B), at two levels with
the middle column injured through the bone (C), or at two
levels with the middle column injured through the ligament
and disk (D).
el through the bone (A), at one
Figure 22–20: Shearing requires forces from opposing
directions to pass through the spine at slightly different levels,
resulting in a fracture dislocation.
Figure 22–22: A sagittal CT reconstruction of a fracture
dislocation of the thoracolumbar spine demonstrating marked
vertebral body displacement and canal narrowing.
Figure 22–23: A sagittal MRI of the thoracolumbar spine of
the patient in Fig. 22–22, demonstrating marked canal
narrowing. Note the draping of the spinal cord over the
posterosuperior edge of the caudal thoracic vertebrae.
Figure 22–25: Extension forces occur when the upper trunk is
thrust posteriorly, resulting in an anterior tension and posterior
compression force complex.
Figure 22–24: A postoperative lateral radiograph of the
patient in Fig. 22–22, demonstrating reduction of the spinal
deformity followed by a fusion and stabilization with
segmental pedicle screw anchors spanning three levels above
and below the level of injury.
Figure 22–26: A sagittal T2-weighted MRI demonstrating a
complete fracture–displacement through the L5 vertebral body
because of a distraction–extension injury mechanism.
Figure 22–27: A lateral postoperative radiograph of the
lumbosacral spine following reduction of the
fracture–displacement and stabilization with pedicle screw
instrumentation from L4-S1.
CHAPTER 22 Thoracic and Lumbar Spine Trauma 303
Bracken MB, Holford TR. (1993) Effects of timing of
methylprednisolone or naloxone administration on recovery of
segmented and long-tract neurological function in NASCIS 2.
J Neurosurg 79: 500-507.
This analysis demonstrates that the greatest proportion of all
neurological recovery and of recovery because of treatment with
very high doses of methylprednisolone within 8 hours of injury
occurs below the lesion.
Bracken MB, Shephard MJ, Collins WF. (1990) A randomized,
controlled trial of methylprednisolone or naloxone in the treatment
of acute spinal cord injury—Results of the second National Acute
Spinal Cord Study. N Engl J Med 322: 1405-1411.
The first controlled trial of methylprednisolone evaluating its
effect on neurological recovery in acute spinal cord injury
patients.
Bradford DS, McBride GG. (1987) Surgical management of
thoracolumbar spine fractures with incomplete neurological
deficits. Clin Orthop Rel Res 218: 201-216.
The authors note that neurological recovery was greater with
anterior decompression mainly as a result of improved canal
clearance.
Carlson GD, Minato Y, Okada A. (1997) Early time-dependent
decompression for spinal cord injury—Vascular mechanisms of
recovery. J Neurotrauma 14(12): 951-962.
The authors found that a critical window of 1-3 hours after the
initial spinal injury exists before an electrophysiological decline
of evoked potentials of the spinal cord begins.
Chapman JR,Anderson PA. (1994) Thoracolumbar spine fractures
and neurological deficits (review). Orthop Clin North Am 25: 595-
612.
A comprehensive review of thoracolumbar fractures and the
appropriate management of these injuries.
References
Abe E, Sato K, Shimada Y et al. (1997) Thoracolumbar burst
fracture with horizontal fracture of the posterior column. Spine
22(1): 83-87.
Nine patients with a burst fracture and a horizontal fracture of
the posterior column were successfully treated conservatively
except for one patient that required posterior spinal fusion
secondary to a worsening kyphotic deformity.
Alanay A, Acaroglu E,Yazici M et al. 2001 Short-segment pedicle
instrumentation of thoracolumbar burst fractures—Does
transpedicular intracorporeal grafting prevent early failure? Spine
26(2): 213-217.
This paper demonstrates that transpedicular intracorporeal
grafting in the treatment of burst fractures does not have a
detectable effect on the rate of reconstruction of the canal area
or on remodeling. Spinal canal remodeling was observed in all
patients regardless of grafting.
Bohlman HH, Kirkpatrick JS, Delamarter RB. (1994) Anterior
decompression for late pain and paralysis after fractures of the
thoracolumbar spine. Clin Orthop Rel Res 300: 24-29.
Anterior decompression of the thoracolumbar spine for chronic
pain after thoracolumbar fractures is a safe and effective treatment
for patients even as long as 5 years after the initial injury.
Daffner RH, Deeb ZL, Rothfus WE. (1987) Thoracic fractures and
dislocations in motorcyclists. Skeletal Radiol 16: 280-284.
A radiological evaluation and illustration of various thoracic
spinal injuries sustained in high-energy trauma patients.
Denis F. (1983) The three column spine and its significance in the
classification of acute thoracolumbar spinal injuries. Spine 8(8):
817-831.
The original paper describing the division of the vertebral
column into three columns to help assess spinal stability.
Denis F, Burkus JK. (1992) Shear fracture dislocations of the
thoracic and lumbar spine associated with forceful hyperextension
(lumberjack paraplegia). Spine 17: 152.
A description of the unusual fracture dislocation associated with
a distractive extension–type injury mechanism.
Ferguson RL,Allen BL Jr. (1984) A mechanistic classification of
thoracolumbar spine fractures. Clin Orthop 189: 77-88.
The authors categorize spinal injury as a result of the
mechanism of injury with various grades according to the
severity.
Flanders AE. (1999) Thoracolumbar trauma imaging overview.
Instruct Course Lect 48: 429-431.
A review of the various thoracic imaging modalities available
to the spine surgeon.
Соседние файлы в папке Библиотека им академика М.И. Перельмана