Nghiên cứu đặc điểm thương tổn giải phẫu và kết quat phẫu thuật điều trị gãy cột sống ngực thấp và thắt lưng không vững do chấn thương bằng nẹp vít tt tiếng anh

1

BACKGROUND
A thoracic and lumbar spinal injuries account for the
majority, about 90% of spinal injuries. In which, thoracolumbar
spine hinge vertebra (T11 - L2) and lower lumbar (L3 - L5)
account for about 84%, mainly with the indirect mechanism.
Classification emphasizes on: the form of injury, integrity of the
posterior ligamentous complex and nerve damage. The role of
the posterior ligamentous system in the stable spinal structure is
confirmed and appreciated by many authors. This is an issue
that needs to be paid more attention to in the diagnosis and
treatment of spinal injury in Vietnam when no previous research
has specifically and fully mentioned before. For surgical
indication,the authors based on the loss of steadiness of the
injured spinal vertebra on the basis of the morphologic damage,
nerve damage, and posterior ligamentous complex. However,
each indication has its own advantages and disadvantages.
Recent studies have been made on the validity and
reliability of Vaccaro AR’s TLICS (thoracolumbar injury
classification and severity score) and indicate cases where
scores of 1 to 4 had to undergo surgery late after a
conservative treatment period, or narrow scope of application
in the multiple vertebral fracture group under the indication
of McCormack and Wood KB. Posterior approaches for
treatment of thoracic spinal injury is becoming more and
more popular, effective and dominant. The efficiency of
multiple vertebral fracture surgery has been enhanced, and
demonstrated in studies by Smith JS, Ataka H., Kaminski A..
The findings of Greenberg MS about degenerative
joint diseaserequired for early surgery after 3 years in long

band fixations (≥ 4 bands) after 8 to 9 years in short band
fixations (2 to 3 bands). Therefore, from these issues, we
carry out the topic: “Study on surgical injury characteristics
and results of surgery for treatment of the lower thoracic and
lumbar spinal fractures due to traumatic injury by splints and
screws” with two goals:


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1. Description of surgical injury characteristics and
deformation on the image diagnosis, survey of TLICS
and LSC values in lower thoracic and lumbar spinal
injury.
2. Evaluate the results of surgery for the treatment of
lower thoracic and lumbar spinal fractures with
posterior splints and screws.
CHAPTER 1. OVERVIEW
1.1. Surgery
The lower thoracic and lumbar spine consists of a relatively
straight, vulnerable thoraco- lumbar spine hinge vertebra (T11 L2) by a longitudinal compression and a lower lumbar vertebra
(L3 – L5) with a physiological curve opening backward to
absorb force in the spring type so that it causes less injury.
Vertebral body has weak structure in from column, stable structure
in middle and back columns. Thus, injury often occurs in the front
column under the vertical compression mechanism. According to
Benzel E.C., the proportion of periosteum and bone marrow affects
the bearing capacity and the anti-screw loosening strength. This rate
is higher in the spinal stalk than in vertebral body and higher in the
thoracic - lumbar spine hinge vertebra than in lower lumbar

vertebra. Therefore, spinal stalkis the strongest part of the vertebrae
and the T11 - L2 segment is stronger than the L3 - L5 segment. The
joint system between vertebrae is composed of two main types of
joints: Cartilaginous (semi-moveable) joint and the Synovial (freely
moveable) joint. Of which, the Synovial (freely moveable) joint
and ligament joint (rear ligament system) play an important role in
steadiness, flexibility and maintaining the amplitude for movement
of the spinal column.The vascular system nourishing the thoracic
and lumbar marrow, including the root vascular system, spinal
marrow vascular system and coronary artery network. Accordingly,
Adam kiewiczcung artery provides mainly for 4/5 marrow in cross
section from T8 to conus medullaris.
1.2. Biological mechanisms behind injury and nerve
damage in spinal injury
1.2.1. Biological mechanisms behind injury
According to Benzel E.C., the force acting on the spinal


3

column, in terms of the three-dimensional space system on each
coordinate axis, has two axial sliding motions and two
reciprocating rotating movements that produce 12 movements
around the instantaneous axis of rotation (IAR), forming up to
six levels of free movement around the IAR axis in association
with each other to creating forces: press – compression, cutting
– shearing, twisting, stretching – tearing resulting in different
forms of damages in a trauma. Instantaneous rotation axis is the
imaginary point in or around the vertebrae where the spinal
segment rotates under the impact force. When the impact force is

non-coaxial with IAR, it generates a bending moment (M) of
magnitude equal to the magnitude of the force (F) multiplying
by the distance from the point of impact to the instantaneous
rotation axis (D). The bending moment (M) is defined as the
product of the force (F) applied to the lever arm and the length
of the lever arm (D) : M = F x D.
1.2.2. Nerve damage
In spinal trauma, there are four major traumatic
mechanisms involved in nerve deformation in the long term:
extrinsic nerve compression, diffusion, arch effect on the vertical
plane, arc effect on the horizontal plane. It has two forms of lesions:
primary lesions and secondary lesions. Disorders or malfunction of
nerve cells due to the mechanism of: cell destruction leads to nerve
cell death and cell deformation, metabolic disorders leading to
temporary or permanent malfunction. Surgery removing the
compression factors can prevent, overcome cell deformation and
metabolic disorders. Secondary nerve damage may be prevented
partially at least by medicine interventions: anticoagulant medicine
therapy and corticoide therapy are recommended to use as soon as
possible within the first 8 to 72 hours after injury.
1.3. Classification of injuries
1.3.2. Classification of Denis (1983)
In 1983, Denis introduced the three column concept of
spinal fractures: anterior column (the anterior vertebral body, ½
anterior annulus fibrosus, and anterior longitudinal ligament),
middle column ( posterior longitudinal ligament, ½ posterior
annulus fibrosus, and posterior wall of the vertebral body), the


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posterior column (spinal canal vein, marrow, posterior ligament
system, posterior arch).
Denis divides the vertebral body injury into four types:
compression fracture (anterior column damage, no injury to the
middle column, possible injury to the posterior column), burst
fracture (injury to the middle and posterior column by the
mechanism of vertical compression in combination with
bending, turning, and the posterior fracture piece may press the
spinal canal), distraction fracture (the fracture lies at the same
level in the vertical plane, the fracture lies in two levels in the
vertical plane causing injury to bones, ligaments and annulus
fibrosus), dislocation fracture (severe damage to all three
columns causing instability).
Denis introduced the concept of “stable and unstable spinal
injuries” as the basis for indications for treatment in spinal
injuries. The term “stability fracture” includes mild or moderate
subsidence, no injury to the middle and posterior columns,
indicating conservative therapy, early movement practice.
There are three types of instability based on the relationship
between morphological and neurological damages: mechanical
instability, neurological instability, mechanical - neurological
instability, and surgical indication.
1.3.3.Classification after Denis
McCormack classified fractures based on three factors: the
breaking degree of the vertebral body, the cohesion of fractured
pieces, the kyphosis being quantified on a scale of 1 to 3 points
on each factor by severity status. The higher the point, the more
severe the injury. Indication for surgery in case of 6 – 9 points.
VaccaroA.R., gave the TLICS classification based on three

important traumatic features: injury morphology, integrity of
the posterior ligament system, and nerve damage. Indication: 510 points => surgery, 1 - 3 points => conservative treatment
and 4 points => priority for surgery.
1.4. Medical imaging methods
3 main methods: conventional x – ray imaging, computerized
tomography and MRI.


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1.4.1. Conventional x – ray imaging
Conventional X-ray imaging has diagnostic value: position;
discontinuity of three lines: inter- posterior spinal cord, inter-joint
block, inter- horizontal spinal cord; vertebral traumas, angular
bending of the traumatic area and the distance between joint
blocks and posterior spinal cord. The advantage of conventional xray compared to computerized tomography and magnetic
resonance imaging (MRI) is that it can be investigated in a
dynamic state to diagnose suspected cases of semi-dislocation.
1.4.2 Computerized tomography (CT scan) of of spine
CT scan have a accuracy rate (sensitivity) of over 98% with
bone damage, which is of high value in the classification of
spinal fractures. Determination of bone loss: reduction of the
height of the anterior column, fracture line, separate fracture
piece and compression position, joint block lesions, spinal
canal, plates, bending angular deformations or dislocation,
spinal canal narrow levels. However, it is difficult to assess soft
tissue lesions such as ligaments, nerves.
1.4.3. MRI of spine
Magnetic resonance imaging may determine the damage in
marrow, soft tissue, posterior ligament complex. Marrow

edema and marrow contusion without blood bleeding have
same signal image or low signal on T1, high signal on T2.
Acute or semi-acute bleeding has low signal image on T2, in
chronic phase it is a high signal image on T1 and T2. For
marrow breaking, the image shows a persistent breaking of
the injured segment and the marrow edema, accompanied by
haemorrhage. Image of ligament injury: sudden loss of signal
in a signal decreasing region on T1, increasing signal in the
surrounding organisms on T2. Bone damage will have an
image of decreasing the signal on T1, increasing the signal
on T2, can be defined the bone fracture line, fractured piece
compressing the spinal column.


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1.5. Brief history of the study and treatment of thoracic and
lumbar spinal injury
1.5.1. In the world
Surgery for treatment of thoracic and lumbar spinal injury
was first supported by Gorter more than 200 years ago. Prior to
1963, the main treatment was conservative treatment, external
correction, posterior arch cut operation and still have
limitations. Later some authors have applied some methods for
fixation in surgery such as steel string tie, hook, brace, Hartshill
frame which obtained certain results. Posterior surgery actually
developed as Roycamille developed, improved the surgical
procedure with a screw via the spinal canal (1963 - 1975). This
method was then modified by Margel into cluster screw with
5º-15º slanted direction, which is widely used in surgery. Today,

these two methods become more and more popular and
effective in treatment
1.5.2. In Vietnam
In Vietnam surgery began to be applied the 70s-80s of the
20th century with the works of Hoang Tien Bao, Vo Van Thanh.
However, in the 90s of the 20th century, spinal trauma surgery
actually strongly developed in Vietnam and successfully
applied both anterior and posterior surgery methods. Cho Ray
Hospital, Viet Duc Hospital, 108 Military Central Hospital,
Military Hospital 103 mainly applied the posterior surgery
method. However, these studies have not addressed the role,
conservation and restoration of the posterior ligament complex,
nor have they adequately assessed the morphologic trauma on
X-ray and investigated the value of TLICS, LSC scales in
surgery.
1.6.2. Some basic issues in posterior hardening
1.6.2.1. Configuration of foot bow screw system
According to Benzel E.C., the screw on the vertebral body
will provide a durable traction and compression force on the
vertebrae to prevent sliding deformation. This force is strongly
influenced by the outer diameter of the screw, the ratio of the
skeleton to the skeleton in the body and the bow, the diameter


7

of the leg. The depth of the screws in the body of the burner is
about 50% - 80%. When the screw is placed in the leg screw
system with adjusting force, it provides a bending and pulling
torque for correcting the flexion. Corners, slides and

compresses the vertical axis. At the same time, it is subjected to
a bending and shearing moment in the opposite direction,
especially at the beginning, end and midpoint of the screw
system when the spine is subjected to a load. Therefore, system
configuration is required. The foot screw must be firm enough
to provide a sufficiently large force to maintain manipulation of
the distal and spine. This is the theoretical basis for the
construction of fixed-length configurations at two points and
fixed longitudinal layers such as three-point bending. The
bending moment provided by these two fixed configurations is
proportional to the length of the structure and has a lateral arm
parallel to the spinal axis. This is the theoretical basis for the
construction of fixed-length configurations at two points and
fixed long bands such as three-point bending. The bending
moment provided by these two fixed configurations is
proportional to the length of the structure and has a lever arm
parallel to the spinal axis. Screw diagrams consist of a straight
diagram (slanted angles down to 0º) and an anatomical diagram
(slanted angles down to 20º - 25º). In particular, linear diagrams
provide superior mechanical biomechanics compared to bolted
anatomy. We need to consider clearly the instability to make
decisions and choose the optimum fixed configuration during
surgery. According to Greenberg MS, joint degeneration
required for surgery should usually occur after 3 years when
fixing the long band and 8 – 9 years when fixing the short band.
Therefore, the authors recommend that if the bone damage is
not severe, fixing short band is appropriate.
.
CHAPTER 2. SUBJECTS AND RESEARCH METHODS
2.1. Research subjects

Study subjects included 89 patients diagnosed with thoracic
and lumbar spinal injury, with single band and instability,


8

operated to correct, fix, compress under the posterior method at
Military Hospital 103 from 12/2010 to 1/2013.
2.1.1. Selection criteria
Patients diagnosed with thoracic and lumbar spinal injury
according to the criteria for each fracture type of the Greenberg MS,
single-band lesions, c operated to correct, fix, compress by screw
under the posterior method . No sex discrimination, age ≥ 18.
2.1.2. Exclusion criteria
Patients have chronic diseases that affect the research results
such as heart failure, liver failure, kidney failure, other
cardiovascular diseases, diabetes ... Multiple injuries, fractures
due to tuberculosis, cancer, mentally ill disorders, no
cooperation in treatment, non-compliance with follow-up and
re-examinaiton procedures, and lack of adequate research
documentation.
2.2. Research Methodology
2.2.1. Research design
A prospective research describes the clinic status with
intervention, evaluates the result results on each patient before
and after surgery.
2.2.2. Sample size
Favorable sample selection includes all patients eligible for
selection criteria and exclusion criteria during the study period.
2.2.3. Data collection method

Information collected according to the unified medical
records include: examination and evaluation of patients before
surgery; participate in surgery, follow up and treat patients after
surgery, directly visit to examine patients after surgery under
the medical record form of the research; check patients who
return for re-examination in the Department of Neurological
Surgery - Military Hospital 103.


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2.2.4. Research content
– Determine the mechanism of injury.
– Evaluate muscle strength and sensory disorders according
to Greenberg M.S. criteria, applicable. – Evaluate the level of
nerve damage accroding to Frankel improvement.
– Evaluate via x-ray images: fracture position, kyphotic
angle, reduction of column height in front of vertebral body,
injury level of vertebral body according to McCormack, level
of spinal stenosis, position pressing the spine, type of fracture,
damage to the rear ligament system.
– Surgery for removing, correction, fixation by the screw
and plint as indicated by Greenberg M.S.
– Postoperative evaluation at two points: 10 days after
surgery and last examination (12 months after surgery).
Criteria: Neurological rehabilitation according to Frankel;
results of the correction of the kyphotic angle, the height of the
column in front of the broken vertebra on the conventional xray according to Keynal; backache, labor recovery by Denis;
surgery time, blood loss during surgery, complications,
condition of the screw system.

2.2.5. Data processing method
Use of medical statistic software SPSS 22.0.
2.2.6. Research ethics
The information about the patient’s illness status in the
medical file is completely confidential and only used in the
study with the consent of the Vietnam Military Medical
University, Military Hospital 103.
CHAPTER 3 . RESEARCH RESULTS
3.1. Common features
3.1.3. Causes of injury


10

Labor accident

Injured accident

Traffic accident

Normal accident

Chart 3.3. Distribution rate of accident causes.


11

3.1.4. Mechanism of injury

Chart 3.4. Distribution rate of injury mechanism.

3.2. Characteristics of vertebral injury
3.2.1. Fracture position
Table 3.1. Distribution rate of fracture position.
Fracture position
Quantity
Rate (%)
P1
T11
02
2.25
T12
18
20.22
L1
41
46.07
< 0.001
L2
15
16.85
L3
12
13.48
L4
01
1.12
Tổng
89
100

P2

<
0.001

3.2.3. Fracture group frequency according to Denis classification

Table 3.2. Distribution rate of fracture group.
Type of fracture
Quantity
Rate (%)
P
Compression fracture
17
19.10
< 0.01
Burst fracture
67
75.28
Dislocation fracture
5
5.62
Total
89
100


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3.2.6. Evaluate the fracture

level of vertebral body according
100
100
to McCormack
Compression
82.09
100
fracture

80
60
40

17.91

20
0

0 I0

II

0

0 III

0

Chart 3.8. Distribution rate of fracture level of fracture groups.

3.2.7. Evaluate the cohesion of71.64
fractured pieces according to
Compression
64.71 60
McCormack
80
fracture
60
35.29 40
40
16.42
11.94
20
0
I

II

0 III 0

Chart 3.9. Distribution rate of the cohesion of fractured pieces.
3.2.8. Evaluate
the kyphotic level according to McCormack
100
50
0
Lún
Compression fracture

I

Vỡ

III

Trật

Burst fracture

I

II

II

Dislocation fracture
III

Chart 3.10. Distribution rate of the kyphotic level.


13
71.64
3.2.9. Evaluate
the fracture types64
according
to McCormack
80
.71
60

rating scale
Compression
70
60
50
40
30
20
10
0

fracture

40

35.29
16.4 2

11.94

0 50

7 0

6

09 0

Chart 3.11. Distribution rate of points.

3.2.10. Evaluate the height reduction of the column in front
of vertebral body
Table 3.3. Height reduction of column in front of vertebral body.
Reduction index
Fracture type
Compression fracture
(n = 17)
Burst fracture
(n = 67)
Dislocation fracture
(n = 5)

Standard
Smallest Biggest Mean
deviation
(%)
(%)
(%)
(+/- %)
50

56

51.35

2.29

20

56

35.78

7.54

20

35

27

5.7

p

< 0.001

3.2.11. Evaluate the angle bending of the injured area
Table 3.4. Kyphotic angle of the injured area.

Bending level

Fracture type
Compression fracture
Burst fracture

Smalles
Mea Standard
Biggest n deviation
t

( 0)
(0)
(0)
(+/-0)
19

29

20

40

23.2
4
26.3
7

3.38
3.89

p

<
0.001


14
Dislocation fracture

22

35

28.8

5.26

3.2.12. Fracture types and spinal canal narrow levels
Table 3.5. Table of spinal canal narrow levels.

Canal narrow
level
Fracture types
Compression
fracture
Burst fracture
Dislocation
fracture
p

Quantity

Not
narrow

Narrow < 50%

Narrow ≥ 50%

Quantity

%

Quantity

%

3

17.65

0

0

67

14
(82.35)
8 (11.94)

26

38.81

33

49.25

5

0

2

40.00

3

60.00

17

< 0.001

3.2.13. Causes of spinal canal narrow

Chart 3.12. Distribution rate of compression causes.
3.2.14. Spinal canal compressing positions


15

Chart 3.14. Distribution rate of spinal canal compressing positions.
3.2.15. Fracture type and spinal decompression methods
Table 3.6. Decompression method.
Decompression

Direct
Quantity

%

Fracture types
Compression fracture
Burst fracture
Dislocation fracture

3
34
3

Indirect
Quantity
%

17.65
50.75
60.0

14
33
2

82.35
49.25
40.0

3.2.16. Decompression time

Chart 3.16. Rate of decompression time.

3.2.17.Decompression group and deformation
Table 3.7. Decompression group and deformation.
Deformation
Fracture types
Compressio Group 1

Quanti
-ty
6

Smalles
Standard
Biggest Mean
t
deviation
    



20 50 29 52 25.1 50.3 3.1 0.8


16
n

fracture
Burst
fracture
Dislocation
fracture

Group 2
Group 1
Group 2

11
37
30

19 50 29 56 22.1 51.9 3.1
20 25 35 50 27.7 38.5 3.2
20 20 40 56 24.6 32.3 3.9

2.6
6.9
6.9

Group 1

5

22 20 35 35 28.8 27.0 5.2

5.7

3.3. Injury to the posterior ligament system
3.3.1. Fracture types and injury to the posterior ligament
system
Table 3.9. Determine injury to the posterior ligament system by
MRI and surgery.

Criteria
MRI
Fracture
types
Compressio
n fracture
Burst
fracture
Dislocation
fracture
Total

Quantit
y (n)

Surgery

Injury to the
posterior
ligament
system

p

Quantit
Rate Quantit Rate
y
(%) y (n) (%)
(n)
23.53

4
23.53
4
23.53

Quantit Rate
y (n) (%)
17

4

< 0.01
67

10

14.93

10

14.93

10

14.93

5

3

60

5

100

5

100

89

17

19.10

19

21.35

19

21.35

3.3.2. Evaluate fracture types according to TLICS scale


17
100
100

80
60

Compression
fracture

64 .71
53.73

40

5.88

2.99

20
0

4 3.28

29.4 1

1-3 0

0

4

5-10

Chart 3.17. Distribution according to TLICS scale.
3.4. Nerve damage
3.4.1. Nerve damage levels
Table 3.14. Nerve damage levels.
Frankel level
A
B
C
D1
D2
D3
E
Quantity
6
3
11
1 6
8
54
3.4.3. Nerve damage and the spinal canal narrow levels in
each fracture type
Table 3.16. Spinal canal narrow levels and nerve damage.

Narrow level - ND Not narrow

< 50%

≥ 50%

ND No ND ND No ND

Fracture types
Compression fracture 2
13
1
1
Burst fracture
0
8
3
23
Dislocation fracture
0
0
0
2
Total
2
21
4
26

p

ND No ND

0
26
3
29

0
7
0
7

> 0.05
< 0.05

3.5. Evaluation of surgery results
3.5.1. Near result
3.5.1.3. Results of deformation correction 10 days after surgery
Table 3.20. Results of deformation correction
Deformation
Fracture type
Compression Group 1
fracture
Group 2

Quantity
6
11

Smallest

2
2


12
14

Standard
deviation
 



16 6.6 14.6 3.3 1.5
18 4.5 15.7 3.2 1.2

Biggest

10
10

Mean


18
Group 1
Burst
fracture
Group 2
Dislocation
Group 1
fracture

37
30
5

2
2
8

4
5
7

19
33
10

15 6.9 10.5 3.2
15 8.5 10.2 7.7
15 9.0 10.2 1.0

1.2
2.3
3.1

3.5.1.4. Results of neurological recovery 10 days after surgery
Table 3.21. Results of neurological recovery
Frankel –
10 days after surgery
Total
Bradford
A B
C D1 D2 D3
E

level
A
6
6
B
3
3
C
6
3
2
11
Before
D1
1
1
surgery
D2
2
4
6
D3
3
5
8
E
54
54
Total
6

3
6
3
2
6
63
89
3.5.2. Far results
3.5.2.2. Results of deformation correction in the final examination
Table 3.23. Results of deformation correction
Deformation

Quantity

Fracture types
Compressio Group 1
n fracture Group 2
Group 1
Burst
fracture Group 2
Dislocation
Group 1
fracture

6
11
37
30
5

Smallest Biggest

3
3
3
3
9


15
17
5
7
10


12
11
20
34
12

Mean



19 7.8
20 5.4
17 8.4
17 9.8

20 10.8


17.3
18.0
12.4
11.8
13.2

Standard
deviatio
n


3.5 1.5
3.2 1.0
5.1 2.5
7.6 2.4
1.3 3.9

3.5.2.3. Results of neurological recovery in the final examination
Table 3.24. Results of neurological recovery.
Frankel –
Bradford
levels
Before
A

Final examination
A

B

4

2

C

D1

D2

Total
D3

E
6


19

surger
y

Total

B
C
D1

D2
D3
E

2

4

4

1
2

3

2

2

3

3

2

2

2
1
6

8
54
71

3.5.2.4. Back pain

Chart 3.19. Distribution rate of backache levels.
3.5.2.5 Labor recovery

Chart 3.20. Distribution rate of labor recovery levels.

3
11
1
6
8
54
89


20
87 bands and the broken rate of screws
3.5.2.6. Number
of fixed
100
80
60
40
20

2

0
Quantity

0 screw
0
Broken

Chart 3.21. Number of fixed bands and the broken rate of screws.
CHAPTER 4. DISCUSSION
4.2. Characteristics of vertebral fractures
4.2.1. Position of vertebral body injury
The fracture rate at the thoracolumbar spine hinge vertebra
and vertebra L1 is the highest. This result is consistent with the
anatomical characteristics of the spine segment (which is
considered straight, kyphotic angle of the region 0⁰ - 10⁰), with
the injury mechanism of longitudinal compression type and
consistent with the study results of the local and foreign
authors.
4.2.2. Fracture types
In our study, burst fracture accounts for 74,16%;
compression fracture of 19,10%. This rate is consistent with
indirect trauma and thoracolumbar spine hinge vertebra injury
accounts for the majority with the rate of 94,38% and 85,39%,
respectively. According to Benzel E. C., the traumatic force acting
in the direction of the vertical axis will be coaxial with IAR on the


21

thoracolumbar spine hinge vertebra, therefore burst fracture,
compression fracture are more commonly seen.
4.2.3. Vertebral fracture level, the cohesion of fractured pieces,
height reduction of front column and kyphotic angle in the
injured area in terms of each fracture type
In our research, deformation was studied and evaluated for
each fracture group and found that it depended on: the degree
of height reduction in vertebral body, breaking degree of
vertebral body, cohesion of fractured pieces, especially injury
in the middle column. This is consistent with McCormack's
judgment. However, there are other related factors such as the
integrity of the posterior ligament complex, joint block lesions.
Thus, a full evaluation of the correlations between the factors in
each fracture group has given us a more comprehensive view of
deformation in spinal injuries as a basis for selecting an
appropriate method for stabilizing and maintaining a stable
structure in surgery. To overcome the possible kyphotic
complications, besides the correction, restoration of kyphotic
angle of the area and height of the vertebral body, the
restoration and conservation of the posterior ligament complex
is necessary.
4.2.4 Spinal canal narrow levels, causes and compressing
positions
Through the computerized tomography image of the
fractured vertebra, we have realized that: compression fracture
with low spinal canal narrows rate accounts for 17.65%; of
which 100% of the spinal canal narrow is < 50% due to the
posterior bending angle of the vertebral body at the ½ above
position. Burst fractures of spinal canal narrows group

accounts for the majority, about 88.06%; of which narrow level
≥ 50% is about 49.25%; the reason is that fractured pieces
accounts for the majority (96.6%) and compression at the
position of ½ above accounts for the majority (84.7%). Group
of dislocation fracture has 100% of spinal canal narrows; of
which narrow level ≥ 50% makes up 60%, because the


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vertebral body combines with broken bones/fractured pieces;
compression position at ½ below accounts for 100%.
4.3. Injury in the posterior ligament system
On clinic and conventional X-ray image, it has suspicious
injury signs of the posterior ligament system as a basis for
magnetic resonance imaging to determine the lesions: large soft
tissue injuries, increased distance between posterior spinal cord
and kyphotic angle of ≥ 20º. Dislocation fracture in the
posterior ligament system accounts for the largest percentage
(100%), burst fracture group is 14.93%, compression fracture is
23.53%. All of these cases have a kyphotic angle of > 20º. The
posterior ligament complex has an effect on the angular
bending distortion of the traumatic area. Thefore, during
surgery we have focused on preserving and restoring the
posterior ligament complex, especially the ligament on the
spinal cord and joints.
4.4. Nerve damage
In the study, we have evaluated the nerve damage in each
fracture type, based on the degree of spinal canal compression
and have found that: the compression fracture causes a lower

rate of nerve damage (17.65%) and shows no relation to the
spinal canal narrow levels, the cause of nerve damage may be
due to stretch or arch effects mentioned by Benzel E.C.; burst
fractures of vertebral body causing nerve damage accounts for
43,28% and 100% of spinal canal narrow, shows a relation
between nerve damage and the spinal canal narrow levels;
dislocation fractures causing nerve damage accounts for 60% ,
of which 100% have spinal canal narrows ≥ 50%.
4.5. Surgery
4.5.1. Survey for surgical indication
Via the survey on the LSC and TLICS scale, we have found
that all indications have advantages and disadvantages, and it’s
necessary to fully evaluate 3 the most important traumatic
characteristics: morphological damage, the posterior ligament
system and nerve damage and the relationship between them.
At the same time, we mention all four fracture types and take


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into account the characteristics of the fracture position when
indicating. However, the important goal of the indication is to
offer the best choice for surgical method to make sure stable
correction/fixation and effective decompression.
4.5.4.3. Result of stable correction
Considering the corection result and maintenance of angular
bending deformation of the trauma area, we have realize that
compression has variable amplitude for kyphotic angle and the
reduction in the column in front of the fractured vertebra is stable
during the process, it proves the correction effectiveness and

stable fixation maintenance. For burst fracture group, the
corection result and maintenance of stable structure shows a
higher variable amplitude for kyphotic angle but within the
allowable limit. For dislocation fracture, the injury on the
posterior ligament system, moveable and immoveable joint
system is quite high that damages the link system of spinal
vertebra and make the fractured vertebra move, thus seriously
affect the stable structure of the spine. This causes difficulties in
the correction and stable fixation of the injured vertebra.
Thus, during surgery we have used the steady foot bow screw
system (short band type) to fix directly to the injured vertebral
body to adjust maximum the sliding restoration and recover the
stable structure, combine with restoration of ligaments on the
spines. As such, it makes sure of providing sufficient force and
support for the screw system in the correction and fixation to
restore and maintain the stable spinal structure. This is the result
of a combination of fixed configuration options, focusing on
structural traumatic characteristics of each fracture type with
preservation, restoration of joint block, the posterior ligament
complex, especially ligaments on the spinal cord.
4.4.4. Nerve recovery
In this study we assessed nerve recovery at two points: 10
days after surgery and the final examination from the 12th
month after the surgery (average follow-up time is 14.47
months). We found that 10 days after surgery there was no case


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becoming more severe and 17 out of 35 cases with nerve

damage recovered at least one Frankel degree, accounting for
48.57%, of which 12 cases recovered 2 Frankel degree or
totally recovered, accounting for 34.29%. However, there were
still 18 cases, accounting for 52.94%. This is a positive
predictive factor that demonstrates that the surgical approach
takes an effect, contributing to the elimination of the risk of
secondary nerve damage and to facilitate the recovery process.
At the last examination from the 12th month after surgery, we
realized that the recovery was very clear and remarkable. The
total number of recovered cases was 27/35, accounting for
77.14%, the number of cases recovered at least two degrees
Frankel compared to pre-surgery was 13, accounting for
37.14% and the number of cases fully recovered was 17,
accounting for 48.57%. Comparisons with the level of nerve
damage before surgery showed significant meaningful
differences. However, there were still 8 cases not recovering at
all under Frankel scale (4 cases of Frankel A, 2 Frankel B and 2
Frankel C), accounting for 22,86%.
CONCLUSION
Through the study of 89 patients experiencing the unstable
lower thoracic and lumbar spinal fractures due to injury, such
patients were indicated for a surgery to fix, correct and
decompress by a posterior low band screw system combining with
restoration and conservation of ligaments on the spinal cord, we
draw two conclusions as below:
1. Surgical injury characteristics, TLICS and LSC survey
- The fracture rate at the thoracolumbar spinal vertebra
accounts for the majority (about 85,39%), the fracture position
is not equal and the difference is statistically significant. Of
which fracture at L1 has the highest rate of 46,07%; at L4 has

the lowest rate (1,12%).
- There are statistical difference at the fracture rates among
three fracture types, of which burst fracture accounts for 75,28%.


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- There are statistical difference at the fracture rates among
three fracture types in terms of angular bending at the injured area
and reducing the height of anterior column. Compression fracture
(22,12 ± 2,78; 51,35 ± 2,28%); burst fracture (26,24 ± 3,87; 34,6
± 7,32%); dislocation fracture (28,8º ± 5,26; 27 ± 5,7%).
- The spinal canal narrow levels and fracture types has a
correlation (p <0,001). Of which, burst fracture and dislocation
fracture with the spinal canal narrow are 88,06% and 100%,
respectively. Causes of spinal canal narrow due to the fractured
bone and compressing at the position of ½ above accounts for
85,07% and 79,11%, respectively.
- The connection between fracture types and nerve damage is
not found. However, there a statistical correlation between the spinal
canal narrow levels and nerve damage in each fracture types.
- The injury rate at the posterior ligamentous complex has
a correlation with fracture types and affects the angular bending
of the injured areas. However, this effect has statistical meaning
in the burst fracture group.
- When TLICS is used independently in the surgical
designation, it may lead to omission of surgical indications.
LSC has a narrow application scope when considering the burst
fracture group.
2. Surgical results

Result of correcting deformation, restorating and
maintaining the stable structure of the injured vertebra during
the treatment and the process of monitoring, overcoming the
kyphotic status to develop after surgery in each fracture type:
+ compression fracture: 10 days after surgery (group 1: 6,6 ±
3,3; 14,6 ± 1,5% and group 2: 4,5 ± 3,2; 15,7 ± 1,2%); in the
final examination (group 1: 7,8 ± 3,5; 17,3± 1,5% and group 2:
5,4 ± 3,2; 18,0± 1,0%).
+ Burst fracture: 10 days after surgery (group 1: 6,9 ± 3,2;
10,5 ± 1,2% and group 2: 8,5 ± 7,7; 10,2 ± 2,3%); in the final
examination (group 1: 8,4 ± 5,1; 12,4 ± 2,5% and group 2: 9,8 ±
7,6; 11,8 ± 2,4%).