|Year : 2020 | Volume
| Issue : 4 | Page : 368-372
A prospective study of subaxial spine injuries: An armed forces experience
Vikas Maheshwari1, Maneet Gill2, Aishik Mukherjee1, Rushikesh Gadhavi1
1 Department of Neurosurgery, AFMC, Pune, Maharashtra, India
2 Department of Neurosurgery, Army Hospital (R&R), New Delhi, India
|Date of Submission||06-Aug-2019|
|Date of Decision||07-Oct-2019|
|Date of Acceptance||28-Nov-2019|
|Date of Web Publication||20-Jul-2020|
Department of Neurosurgery, Armed Forces Medical College, Pune - 411 040, Maharashtra
Source of Support: None, Conflict of Interest: None
Introduction: Cervical spine injuries account for 3% of all polytrauma patients and can lead to quadriplegia, significant functional loss, and permanent disability. A large spectrum of such cases requires surgical decompression and reconstruction with variable neurological outcomes. Aims and Objectives: The aim of the study was to critically review the subaxial cervical spine injury cases managed surgically with different types of implants at a tertiary level armed forces hospital and analyze their postoperative outcomes. Methods: A prospective analysis of patients (n = 85) of subaxial cervical spine injury was carried out between October 2014 and December 2017. The last patient of our study on July 17 was followed for 5 months. Surgical decompression and stabilization were done in 71 patients whereas 14 patients were managed conservatively. Pre- and post-operative neurological outcome was assessed by the American Spinal Injury Association (ASIA) score. Results: There were 81 men and 04 women whose mean age was 39 years (range 16–78 years). The most common cause of injury was road traffic accidents (45%, n = 38). C5-C6 was the most common site of injury 46% (n = 39). ASIA Grade C (n = 27, 32%) was the most common presentation. Seventy-one cases were treated surgically; 95% (n = 68) of through the anterior approach, 2 by the posterior approach and one by a combined approach. Of the 44 patients operated within 24 h of injury, 19 (43%) had a two-grade improvement in their ASIA scores, 5 (11%) had a one-grade improvement and the remaining 20 showed no change. Only one patient out of 27 patients operated 24 h after the injury showed improvement in ASIA grade. Conclusion: Subaxial cervical spine injuries are complex and a definite treatment algorithm is still a work in progress. However, early surgical decompression and stabilization lead to good neurological outcome in the majority of cases.
Keywords: American spinal injury association score, subaxial cervical spine, subaxial injury classification system score
|How to cite this article:|
Maheshwari V, Gill M, Mukherjee A, Gadhavi R. A prospective study of subaxial spine injuries: An armed forces experience. Med J DY Patil Vidyapeeth 2020;13:368-72
|How to cite this URL:|
Maheshwari V, Gill M, Mukherjee A, Gadhavi R. A prospective study of subaxial spine injuries: An armed forces experience. Med J DY Patil Vidyapeeth [serial online] 2020 [cited 2021 May 11];13:368-72. Available from: https://www.mjdrdypv.org/text.asp?2020/13/4/368/290166
| Introduction|| |
Cervical spine injuries are a challenge to deal with due to the potentially devastating outcomes that are associated with it. More than half of the spine injuries and a majority of spinal cord injuries are secondary to trauma of the subaxial cervical spine., Subaxial cervical spine is classically from C3-C7. Most commonly, injuries of the subaxial cervical spine occur between C5-C7. A number of factors such as morphology of the fracture, alignment of the spine and its effect on spinal instability as well as the neurological status of the patient dictate the management for such cases. Although classifications such as the subaxial injury classification system (SLIC) system and the AO spine SLIC have recently been introduced to guide therapeutic decision-making and prognostication of patients with subaxial spine injury, the evolution of a reliable and reproducible classification system is still at large., A proven algorithm for surgically approaching such patients is still to be formulated and is very much subject to the surgeon's discretion at present. The surgical approaches can be either anterior, posterior or a combination of both and should be tailored according to fracture morphology and patient-specific factors.,
| Methods|| |
A critical review of 85 patients of subaxial cervical spine injury admitted and treated at a tertiary level armed forces hospital was done. The period of study was from October 2014 to December 2017. The record of each patient was maintained meticulously, and due clearance was taken from hospital ethical committee. The patients were evaluated with digital radiographs, computerized tomography(CT), and magnetic resonance imaging (MRI) of the cervical spine. All patients of unstable spine, traumatic prolapsed intervertebral disc (PIVD), subluxation, locked facets with complete or incomplete cord injury were operated. Patients managed conservatively were those who had either severe autonomic dysfunction or refused surgery. Surgical decompression with a variety of reconstruction techniques was done in 71 patients whereas 14 patients were managed conservatively. No steroids were used either in preoperative or perioperative period. Pre- and post-operative neurological outcome was assessed with the American Spinal Injury Association (ASIA) grading.
Six-eight patients out of a total of 71 underwent surgery through an anterior approach. Of the remaining three patients, one had a combined approach due to a locked facet and other two had a posterior approach [Table 1]. The mean time lag from the time of injury to surgical intervention was 36 h (2 h – 5 days).
A variety of reconstructive procedures were done in the form of simple bone graft and plating (n = 6), polyether ether ketone (PEEK) with plating (n = 33), the coalition system (n = 10), the paramesh cage (n = 15), the expandable cervical PEEK cage (n = 4), and lateral mass/pedicle screw and rod (n = 3) [Table 2].
| Results|| |
There were 81 men and 04 women (range 16–78 years). The minimum follow-up was 04 months to a maximum of 36 months, and the mean follow-up period was around 11 months. The most common cause of subaxial spine injury was road traffic accidents (RTAs) (45%, n = 38) followed by accidental falls (26%, n = 22), as shown in [Figure 1]. C5-C6 was the most common site of injury seen in 46% (n = 39), as depicted in [Figure 2]. Most of the patients were in ASIA Grade C (n = 27, 32%) at time of presentation [Table 3]. Morphologically, traumatic subluxations were the most common form of injury seen in 40% (n = 34) with up to two-third having locked facets [Table 4]. Preoperative reduction was attempted in all patients with traumatic subluxation (n = 34). Successful reduction was achieved in 85% (n = 29) and in the remaining five patients, it failed probably due to associated facet injuries. These were reduced intraoperatively.
Postoperatively, hoarseness of voice was encountered in three patients. There was transient dysphagia in two patients which was managed conservatively. One patient of traumatic PIVD C5-C6 who initially underwent anterior cervical discectomy with PEEK fusion had implant dislodgement at 6 weeks after surgery with no worsening of neurological status. He was taken up for repositioning of PEEK along with anterior plating. There were no cerebrospinal fluid leaks or deaths. In our series, of the 44 patients operated within 24 h of injury, 19 (43%) had a two-grade improvement in their ASIA scores and 5 (11%) had a one-grade improvement whereas of the 27 patients operated after 24 h of injury, only one patient had a one-grade improvement in the ASIA score [Table 5].
| Discussion|| |
Cervical spine injuries account for up to 3% of injuries in trauma victims and can lead to quadriplegia, significant functional loss, and permanent disability. In the US, the most common cause of cervical spine injuries are RTAs accounting for 40%–50% of the cases. In our study, similarly, 45% (n = 38) injuries were due to RTAs [Figure 1].
A majority of cervical spinal cord injuries are secondary to trauma of the subaxial cervical spine with more than half of them occurring between C5 and C7., C5-C6 was the most common site of injury seen in 46% (n = 39) of the cases [Figure 2].
A number of factors such as age of the patient, morphology of the fracture, alignment of the spine, and its effect on spinal instability as well as the neurologic status of the patient dictate the management for such patients. In general, all patients with blunt trauma to spine should be screened for subaxial cervical injuries once hemodynamically stable. Although plain radiographs are most frequently the initial investigation, their sensitivity (70%) is far less than computed tomography (CT) scans which with a sensitivity of 99% and specificity of 100% not only helps in more detailed evaluation of subaxial spine injuries but also rules out other injuries of the cervical spine.
MRI is useful in subaxial cervical spine injury for the assessment of cord compression and status of the discoligamentous complex (DLC). This comprises of the supraspinous and the interspinous ligaments, disc, along with facet capsule. It also shows the presence of hematoma, cord contusion and hence is critical not only for determining the surgical approach, but also has prognostic significance.
The was proposed by the spinal trauma study group after the advent of MRI in 2007, which incorporated injury morphology, integrity of the DLC, and the neurological status of the patient for the evaluation of patients with subaxial spine injury. Each of these categories was individually analyzed and given a score [Table 6].
The variable patterns of fracture and dislocations of the subaxial cervical spine has led to significant constraints in the development of a classification system that can be reliable, reproducible, and at the same time, enable in therapeutic decision-making. One of the first classification systems for subaxial spine injuries was proposed by Ferguson and Allen in 1982 and later, the classification by Magerl et al. was proposed in 1994 for thoracic and lumbar spine which was extrapolated to classify subaxial spine injuries., However, their effectiveness was compromised by the fact that these were based on plain radiographs and did not take into consideration the neurological status of the patient.,
For the first time, more objectivity was brought in managing such cases. A conservative treatment is indicated for a score of 3 or less, whereas for patients with a score of 5 or more surgical intervention is recommended. Score of 4 is considered equivocal which could either be managed conservatively or left at the discretion of the surgeon.
More recently, in 2016, the AO spine forum has devised a new subaxial cervical spine injury classification system to overcome the potential pitfalls of the SLIC system. Apart from fracture morphology and the neurological status of the patient, other factors like facet injury and the presence of specific modifiers such as incomplete disruption of the posterior ligamentous complex, critical disc herniation, vertebral artery injury, and the presence of comorbid spine conditions such as osteoporosis, diffuse idiopathic skeletal hyperostosis, ossification of the posterior longitudinal ligament, and ankylosing spondylitis were considered in the AO spine classification system.
The management of patients with subaxial cervical spine injuries following initial hemodynamic stabilization involves adequate neck immobilization in a rigid cervical collar. Early closed reduction with traction forms an important initial intervention in those with dislocations. It is reported that adequate alignment can be achieved in up to 70% of cases with traction., In our study, preoperative reduction was attempted in all patients of traumatic subluxation (n = 34) and successful reduction was achieved in 85% of cases (n = 29).
Facet injuries usually result from a flexion and distraction injury and may or may not be associated with rotation. While closed reduction should be initially attempted in these patients, in cases of failed closed reduction, an open reduction can be performed by either an anterior or a posterior approach. In the anterior approach after the discectomy, distraction can be attempted to unlock the facet joints and reduce the dislocation. Once reduction is achieved, interbody fusion can be performed with either autologous graft or implants as per the requirement. The surgical approach anterior or posterior is guided by the morphology of the injury, the site of compression and the technique of reconstruction chosen. Anterior approaches have the advantage of fewer wound complications and a higher fusion rate whereas postoperative swallowing difficulties may be a significant limiting factor. Burst fractures require restoration of the anterior column and are typically treated through an anterior approach with corpectomy, bone grafting, and anterior plating whereas fractures associated with significant disruption of the DLC may require combined anterior and posterior approaches. Neurological recovery and patient-related outcomes through both anterior and posterior approaches are comparable as per literature review., In our study, the neurological outcome was independent of the implant used [Table 4] as their role is to provide bony support and reunion only.
Literature review suggests that decompression and stabilization should be performed as early as possible after appropriate patient resuscitation to have a good neurological outcome. Fehlings et al., in their study, demonstrated that nearly 20% of patients who underwent early surgery (<24 h) had at least a two-grade improvement in the ASIA score at 6 month follow-up in comparison to only 9% of patients showing two-grade improvement in the delayed surgery group. There was no difference in adverse outcomes in either group.
| Conclusion|| |
Subaxial cervical spine injuries form a wide spectrum of injuries with a devastating array of complications and high propensity for misdiagnosis. The widespread availability of newer imaging techniques like the CT and MRI has allowed for improved diagnostic accuracy. Newer classification systems such as SLIC system and the AO spine subaxial spine injury classification system have come into vogue to aid in therapeutic decision-making and help in prognostication of these patients. The advent of new and improved instrumentation as used in our study for subaxial spine reconstruction has given a plethora of surgical options. However, subaxial cervical spine injuries are complex and a standard treatment algorithm that would fit all ages with coexisting systemic or local pathology has not been established universally. Hence, every case of subaxial cervical spine injury is unique, and management should be based not only on the type of injury but also on patients comorbidities, surgeons experience, availability of resources and should include rehabilitative measures.
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Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2]
[Table 1], [Table 2], [Table 3], [Table 4], [Table 5], [Table 6]