Keywords
cervical vertebrae - operative time - risk factors - prospective studies
Introduction
The burden of disability and rehabilitation with Spinal Cord Injury is immense and
increasing with the advent and easier availability of high-speed vehicles in developing
countries.[1]
[2] But the role and timing of surgical intervention with severe injuries still remains
disputed.[3]
[4]
[5]
[6]
[7]
[8]
[9]
Primary insult to spinal cord caused by compression due to dislocation or burst is
irreversible. This injury further leads to progressive and continuous compression
leading to hypoperfusion of the injured segment increasing the oedema and cord contusion.
Pre-clinical studies have suggested direct correlation between the period of compression
of the cord and the extent of the structural irreversible damage to the cord.[10] This finding has led spine surgeons to offer early surgical intervention to mitigate
the damage and promote neurological recovery in such patients.[3]
[11] An early surgical decompression targets to attenuate a secondary hit mechanism cascade
including ischemia which ultimately leads to permanent loss of function for spinal
cord.[4]
[12] Despite the worldwide use of early decompression in patients with sub axial cervical
fracture dislocation as a standard, it's role in improving neurology and decreasing
mortality/morbidity remains controversial.[3]
[4]
[7]
[11]
[13]
[14] Also there has been recent effort to establish the significance of the extent of
spinal cord decompression in neurological outcomes which have suggested bias in studies
suggesting superiority of early intervention in such patients.[6]
[15]
Multiple factors have been noted to influence the outcome such as injury segment,
cause of the injury, length of the cord oedema segment, pre-operative physiological
parameters, requirement of inotropes, SLIC score and ASIA score.[4]
[6]
[11]
[14]
[15]
[16]
[17]
[18] There is a lacunae in the data of the surgical and functional outcomes of sub axial
cervical spine fractures and dislocations in terms of patient's pre-operative physiological
profile and surgical timing. Also there has been a considerable difference in the
studies performed in the developing world and the developed world with respect to
the surgical and functional outcomes, disability and mortality.[7]
[8]
[19]
[20] This may be due to constraints of resources, sporadic health infrastructure, disregard
for aggressive rehabilitation of the patients with permanent disabilities, lack of
research funding and prioritization of other communicable and curable diseases with
respect to the spinal cord injuries in developing countries.[7]
[8]
[21] In this study, we have aimed to evaluate the risk factors associated with sub axial
cervical spine fractures and dislocations in terms of patient's pre-operative physiological
parameters and surgical timings.
Materials and Methods
A prospective observational study of 26 patients with sub-axial cervical spine fractures
and dislocations who underwent surgery at a tertiary health setup from May 2017 to
May 2019 was conducted. After institutional ethical clearances, informed consents
were obtained from all the participating patients and then they were enrolled for
the study (Protocol No.184/18).
The inclusion criteria were 1) Age of the patient more than eighteen. 2) Patient must
have been admitted within 7 days of injury. 3) Patients with sub axial cervical spine
fracture dislocation who underwent surgery. The exclusion criteria were 1) Patients
with head injuries Glasgow Coma Scale of less than 8/15. 2) Sub axial Cervical Injury
Classification score of less than Four. 3) Pathological fractures and patients with
uncertain follow up. Twenty-six (26) patients fulfilling this criterion were included
consisting of 24 males and 2 females. All patients were evaluated thoroughly, and
their detailed history, demography and clinical radiological data were obtained. Four
physiological parameters respiratory rate, heart rate, blood pressure, PaO2 were documented
pre-operatively. A pre-operative respiratory rate greater than 24, heart rate less
than 60, blood pressure less than 90 systolic or 60 diastolic mm of hg, PaO2 value
in last 24 hours < 94 were given a score of 2 each arbitrarily and patients with score
of more than 4 were assigned to Group U. Patients with score less than or equal to
4 were assigned to Group S. Further, these groups were sub-divided into early (UEarly, SEarly) and late (ULate, SLate) groups with respect to the timing of surgery. Patients taken to surgery within 72 hours
were assigned as early and the rest were assigned as late.[19]
[20]
[22]
The mean age of the patients was 42 years, 18-year-old being the youngest and 68-year-old
being the oldest. High velocity motor vehicular accidents were the most common cause
of injuries followed by fall from height ([Table 1]). Most of the patients were presented to the hospital within 72 hours of injury.
Table 1
|
Characteristics
|
Number (Percentage)
|
|
Number of Patients
|
26
|
|
Gender:
|
|
|
Male
|
24
|
|
Female
|
2
|
|
Mode of Injury:
|
|
|
1. High Velocity Motor Vehicular accident
|
11
|
|
2. Fall from height
|
9
|
|
3. Others
|
6
|
|
Level of Injury:
|
|
|
1. C3-C4
|
10(38.4%)
|
|
2. C4-C5
|
7(27%)
|
|
3. C5-C6
|
5(19.2%)
|
|
4. C6-C7
|
4(15.4%)
|
|
Physiological Parameters:
|
|
|
1. Unstable group
|
17(65.38%)
|
|
2. Stable group
|
9(34.62%)
|
Physiological parameters were noted at the time of presentation, pre-operative and
post-operative daily during hospital stay. Neurological assessment was done using
American Spinal Cord Injury Association impairment scale pre-operatively, post-operatively
and during follow up. All patients underwent radiological evaluation including X-Ray
and magnetic resonance imaging (MRI) of cervical spine to determine the level of spinal
injury, spinal cord compression, associated cord oedema and contusions and status
of inter vertebral discs. The C5-C6 level (n = 10, 38.4%) was most injured in this
series with 10 of the patients having injury at C5-C6 level ([Table 1]); followed by C4-C5 which was the second most commonly injured segment (n = 7, 27.0%);
followed by C6-C7 segment (n = 5, 19.2%); and C3-C4 segment (n = 4, 15.4%). The pre-operative
neurological status was noted and graded based on America Spine Injury Association
grading(ASIA; ASIA-A, 16 cases; ASIA-B, three cases; ASIA-C, four cases; ASIA-D, three
cases) and SLIC (SLIC score four, one case; SLIC score five, seven cases; SLIC score
six, nine cases; SLIC score seven, three cases; SLIC score eight, two cases; SLIC
score nine, two cases).
Associated injuries with sub axial cervical spine injuries were also documented and
relevant radiological examination were done. One patient had bilateral calcaneus fracture
and two had associated long bone fractures. Patients presenting within eight hours
of injury were administered methylprednisolone.
All the patients were taken for surgery as soon as possible and the patients underwent
reduction under general anaesthesia followed by surgery by anterior approach if reduced.
The patients underwent an Anterior-Posterior-Anterior approach for reduction and fixation
of injury segments for irreducible fractures and dislocations. A standard Smith-Robinson
approach was used for anterior discectomy/corpectomy and fusion. For posterior approach,
standard midline approach was taken.
Patients' recovery was monitored in Intensive Care Unit (ICU). Patients were put on
collar for the next 3 months. All patients underwent aggressive physical rehabilitation
post-operative. Patients were called for follow up at 1, 3, 6 and 12 months and neurological
recovery graded by ASIA grade and by X-Ray obtained to assess fusion and position
of implants. The statistical association was calculated by using binary logistic regression
with 95% confidence interval. Mortality was taken as a dependent variable and the
timing of surgery and physiological parameters were taken as independent variables.
Results
All patients were taken for surgery at the earliest after required radiological and
routine investigations. Out of the 26 patients, the fracture-dislocations of 24 patients
could be reduced under general anesthesia in the operation theatre followed by anterior
Discectomy/corpectomy and fusion. In two cases, Anterior-Posterior-Anterior approach
had to be taken for irreducible fractures and dislocations. Mean operating time was
1.5 hours (90 min) for anterior surgery and three hours for Anterior-Posterior-Anterior
approach. Mean blood loss was 150 ml during surgery.
All patients were monitored in ICU and were put on cervical braces for six weeks.
All patients were administered deep vein thrombosis prophylaxis. Aggressive physiotherapy
was done post-operatively and the relatives were taught to care for the paraplegic.
Aggressive rehabilitation was initially aimed at helping patients and relatives understand
the need for weight-shifting maneuvers to prevent pressure sores. Also, patients were
taught to self-catheterize for bladder care. During follow ups, social and vocational
integration of the patient was attempted.
Patients were grouped according to the timing of surgery and pre-operative physiological
parameters of the patients; 15 patients were grouped in Uearly, 2 in Ulate, 5 in Searly and 4 in Slate. Two patients with ASIA grade A improved by one grade at one year follow up. 14 patients
with ASIA grade A succumbed at one year follow up of which 13 belonged to group U.
Two patients each with ASIA Score C and D also showed improvement of one grade each
at one year follow up ([Table 2]).
Table 2
|
Follow up ASIA Scale after 12 months
|
|
ASIA Impairment Scale Pre-operatively
|
ASIA A
|
ASIA B
|
ASIA C
|
ASIA D
|
ASIA E
|
Death
|
Total
|
|
ASIA A
|
0
|
2
|
0
|
0
|
0
|
14
|
16
|
|
ASIA B
|
0
|
2
|
0
|
0
|
0
|
1
|
3
|
|
ASIA C
|
0
|
0
|
1
|
2
|
0
|
1
|
4
|
|
ASIA D
|
0
|
0
|
0
|
1
|
2
|
0
|
3
|
|
ASIA E
|
0
|
0
|
0
|
0
|
0
|
0
|
0
|
|
Total
|
0
|
4
|
1
|
3
|
2
|
16
|
26
|
Patients with unstable physiological parameters who were operated within 72 hours
had outcomes even under intensive hospital care and at one year follow up(p-value = 0.016).
15 patients grouped in UEarly group underwent decompression and fixation within 72 hours of admission and were
having unstable physiological parameters of which 14 patients expired ([Table 3]). In contrast, patients who were physiologically stable and did not require pre-operative
mechanical and ventilator support fared better irrespective of whether the surgery
was performed within 72 hours or later. We could not find a positive association with
early or late surgery groups where they had stable physiological parameters pre-operatively.
Also, while statistically analyzing various clinical predictors by binary logistic
regression method, timing of surgery was found to be not significant in predicting
the outcome(p-value = 0.067). Out of the 26 patients, 14 patients required post-operative
mechanical ventilation support. 11 patients could not make it eventually and expired
because of respiratory arrest or of ventilator acquired pneumonia. One patient developed
deep bed sores and later had systemic infections and succumbed to the same. 12 patients
died during hospital care and four patients died during the follow up period of one
year.
Table 3
|
U
early
|
U
late
|
S
early
|
S
late
|
Total
|
|
Total (percentage)
|
15(57.69%)
|
2(7.69%)
|
5(19.23%)
|
4(15.38%)
|
26(100%)
|
|
Mortality
|
14(53.84%)
|
1(3.84%)
|
1(3.84%)
|
0
|
16(61.53%)
|
|
Alive
|
1(3.84%)
|
1(3.84%)
|
4(15.38%)
|
4(15.38%)
|
10(38.46%)
|
Discussion
Spinal Cord injury due to sub axial cervical fracture dislocation, either complete
or incomplete is an overwhelming injury for the patient, for the family, and also
for the country because of the permanent disability associated with it even with recent
advances in operative techniques and instrumentations and aggressive rehabilitation
protocols.[1]
[2]
[7]
Despite awareness among the public about primary care, many patients were transported
to the emergency room without neck immobilizer. This is suggested by the high number
of complete injury patients in this study compared to studies done elsewhere in the
world. Thus, there is a scope for awareness of the importance of extrication of the
patient from the site of injury and proper immobilization during transport.[7]
[8]
[12]
[23]
The role of timing of surgery in sub axial cervical spine fracture dislocation has
always been controversial, with studies supporting both early and late timing of surgery
present in literature, but very few are prospective and randomized.[4]
[5]
[6]
[11]
[14]
[21]
[24]
[25] In this study, good outcome was reported with incomplete spinal cord injuries while
patients with complete cervical injuries had high mortality rate and morbidity, indicating
that an aggressive approach while selecting patients with complete injury and patients
with physiological unstable parameters for early surgical procedures may not be warranted.[7]
[8]
[9]
[11] Various risk factors have been evaluated with respect to spinal cord injuries like
duration of injury, incomplete surgical decompression, length of oedema segment in
MRI, injury segment and age.[3]
[15]
[17]
[18]
[23]
[24] But very few studies have corelated the pre-operative physiological parameters,
need for inotropes and mechanical support to the timing of surgery and the eventual
outcomes in sub axial cervical spine fracture dislocations. Various studies for evaluating
the timing of decompression have been undertaken but due to various bias caused by
differences in methodology, tools for assessment, number of patients enrolled and
long periods of follow up, the effectiveness of such studies is disputed. The role
of the timing of surgery in treatment of acute spinal cord injuries has been controversial
as no proper randomized study regarding the same is available due to the ethical concerns
of randomizing such patients and denying them early surgery. Aarabi et al.[11] in 2019 concluded in their study that timing of decompression did not influence
neurological improvement but identified length of intramedullary lesion as a main
clinical predictor for the surgical outcome. Seventy percent of patients were operated
after a week in the study conducted by Dhakal et al.[8] but almost half of the patients had neurological improvement despite the delay in
the surgery indicating importance of factors other than the timing of surgery. Study
conducted by Gupta et al.[3] in level 1 trauma center favors early decompression but also had greater mortality
rate in motor complete injury patients and the study had shorter mean follow up of
less than one year. Another study by Admasu et al.[7] set in resource limited set-up concluded that there was no significant advantage
of aggressive early treatment and treaded on fine line advocating proper patient selection
while dealing with complete cervical injuries, but this study had limitations of being
retrospective. We have in this prospective observational study analyzed those patients
with unstable physiological parameters pre-operatively who underwent early surgery
had poor outcomes and high mortality ratio. Patients having stable physiological parameters
had better outcomes and survivability. This suggested that an early surgery in an
already compromised and physiologically unstable patient may lead to a secondary hit
which may become irreversible leading to patient mortality. So, a careful selection
of the patient should be made for early decompression and fixation especially in a
resource limited set-up like India where post-operative ICU beds and intensivists
for management of such patients are scarce.
The goals for sub axial cervical spine fracture dislocation are stabilization of cervical
spine to allow for early mobilization and rehabilitation and also to do an early decompression
of the cord to give the patient every chance of neurological recovery as well as an
attempt to attenuate secondary hit to the spinal cord. These goals should be carefully
weighed against the patient's physiological profile to reduce complications and mortality.
The lack of randomization of this study as well as the small number of study participants
in quadriplegic and paraplegic patients posed a few limitations to the study.
Conclusions
This study concludes that early major surgical procedures in physiological unstable
patients having traumatic sub axial cervical spine fracture dislocation had significant
association as a risk factor in the final outcome of the patients in terms of mortality
and morbidity. Also, patients with incomplete injury and stable physiological parameters,
irrespective of the timing of surgery, had good outcomes in terms of neurological
recovery and mortality. The goals of sub-axial cervical spine surgery should be weighed
against the patient's physiological profile before recommending an early surgery in
all patients as this may offer no benefit to him; instead, this may be associated
with increased mortality and complication rates.
