The Surgical Approach to Subaxial Cervical Spine Injuries

The Surgical Approach to Subaxial Cervical 

Spine Injuries 

An Evidence-Based Algorithm Based on the SLIC Classification System 

Marcel F. Dvorak, MD, FRCSC, Charles G. Fisher, MD, MHSc, FRCSC, 

Michael G. Fehlings, MD, PhD, Y. Raja Rampersaud, MD, FRCSC, F. C. Öner, MD, PhD, 

Bizhan Aarabi, MD, and Alexander R. Vaccaro, MD 

SPINE Volume 32, Number 23, pp 2620–2629 

©2007, Lippincott Williams & Wilkins, Inc. 

Study Design. Systematic review of literature and expert 

clinical opinions of the members of the Spine 

Trauma Study Group were combined to develop and refine 

this algorithm. 

Obejctive. To develop an evidence-based algorithm 

for surgical approaches to manage subaxial cervical injuries 

using a systematic review of the literature, expert 

opinion, and anticipated patient preferences. 

Summary of Background Data. There is lack of consensus 

in the management of subaxial cervical spine 

trauma, in part, because of the lack of a clinically relevant 

system for classifying these injuries. The newly developed 

Subaxial Injury Classification scoring system categorizes 

injury morphology into 3 broad groups, includes 

an assessment of the integrity of the discoligamentous 

soft tissue structures and the patient’s neurologic status, 

and thus guides surgical or nonsurgical treatment. The 

choice of a specific surgical technique and approach is 

currently not evidence based, and this gap in knowledge 

is one which the current article seeks to address. 

Methods. A literature review followed by a consensus 

of experts approach was used to develop the algorithm 

and to ensure face and content validity. 

Results. An algorithm is presented to guide the choice 

of surgical approach in cervical subaxial burst fractures, 

distraction injuries, and translation or rotation injuries. 

The burst or compression injuries and distraction injuries 

are more likely to be treated with a single anterior approach, 

whereas the more severe translation or rotation 

injuries may more commonly be approached posteriorly 

or with combined anterior and posterior surgery. 

Conclusion. This algorithm; derived from the Subaxial 

Injury Classification scoring system, will assist surgeons 

in answering the 2 most common questions they face 

when managing subaxial cervical spine trauma: “Should I 

operate?” and “Which surgical approach should I select?” 

Key words: cervical trauma, surgical approaches, systematic 

review. Spine 2007;32:2620–2629 

From the Division of Spine, Department of Orthopaedics, University of 

British Columbia, Vancouver, Canada. 

Acknowledgment date: March 26, 2007. Revision date: April 30, 

2007. Acceptance date: May 7, 2007. 

Supported by the Spine Trauma Study Group and funded by an educational/research 

grant from Medtronic Sofamor Danek. 

The manuscript submitted does not contain information about medical 

device(s)/drug(s). 

No funds were received in support of this work. Although one or more 

of the author(s) has/have received or will receive benefits for personal 

or professional use from a commercial party related directly or indirectly 

to the subject of this manuscript, benefits will be directed solely 

to a research fund, foundation, educational institution, or other nonprofit 

organization which the author(s) has/have been associated. 

Address correspondence and reprint requests to Marcel F. Dvorak, 

MD, FRCSC, D-609 Heather Pavilion, 2733 Heather Street, Vancouver, 

BC V5Z 3J5, Canada; E-mail: marcel.dvorak@vch.ca 

The management of patients with subaxial cervical 

trauma has lacked consensus among the surgeons who 

treat these patients, particularly in regard to the decision 

to operate and which surgical approach or combination 

of surgical approaches to use. 1 One of the shortcomings 

in identifying optimal treatment for these injuries is the 

lack of standardized nomenclature or a scoring system. 

The literature is replete with reports of surgical techniques 

and approaches for subaxial cervical trauma. 2–10 

However, no one, to date, has been able to systematically 

review and consolidate the literature and then blend the 

results with expert opinion and patient preference to 

produce an evidence-based treatment algorithm. 

The development of evidence-based management recommendations 

for subaxial cervical injuries has been facilitated 

by the development of the Subaxial Injury Classification 

(SLIC) scoring system. 11 This scoring system 

proposes 3 major injury characteristics as indicators, 

which would direct the treatment of subaxial injuries. 

These 3 characteristics are: (1) injury morphology as determined 

by the pattern of spinal column disruption on 

available imaging studies, (2) integrity of the discoligamentous 

soft tissue complex (DLC) represented by 

both anterior and posterior ligamentous structures as 

well as the intervertebral disc, and (3) neurologic status 

of the patient. These 3 injury characteristics are widely 

recognized as predictors of clinical outcome and influence 

treatment recommendations. Within each of the 3 

categories, subgroups have been identified and graded 

from least to most severe (Table 1). 

The SLIC classification divides injury morphology 

into 3 main categories referenced to the relationship of 

the vertebral bodies with each other (anterior support 

structures): (1) compression, (2) distraction, and (3) 

translation or rotation. The components of the DLC include 

the intervertebral disc, anterior and posterior longitudinal 

ligaments, interspinous ligaments, facet capsules, 

and ligamentum flavum. The integrity of these soft 

tissue constraints is thought directly proportional to spinal 

stability and is classified within the SLIC system as 

disrupted, intact, or indeterminate. Neurologic injury is 

the third component of the SLIC system and is inherently 

an important indicator of the severity of spinal column 

injury and may be the single most influential predictor of 

treatment. The presence of an incomplete neurologic injury, 

particularly in the presence of ongoing root or cord 

compression leads to the highest point score (Table 1). 

2620

Subaxial Cervical Spine Injuries • Dvorak et al 

2621 

Table 1. Subaxial Injury Classification (SLIC) Scale 

Points 

Morphology 

No abnormality 0 

Compression burst 11 2 

Distraction (e.g., facet perch, hyperextension) 3 

Rotation or translation (e.g., facet dislocation, 

4 

unstable teardrop or advanced staged 

flexion compression injury) 

Discoligamentous complex 

Intact 0 

Indeterminate (e.g., isolated interspinous 

1 

widening, MRI signal change only) 

Disrupted (e.g., widening of anterior disk 

2 

space, facet perch or dislocation) 

Neurological status 

Intact 0 

Root injury 1 

Complete cord injury 2 

Incomplete cord injury 3 

Continuous cord compression (neuro modifier 

1 

in the setting of a neurologic deficit) 

The SLIC scoring system can be used to direct treatment 

into the broad categories of either surgical or nonsurgical 

by summing the points in each of the 3 categories outlined 

in Table 1. Injuries which score 5 or more points on SLIC 

are all treated surgically, whereas those scoring 3 or less are 

treated nonsurgically. A score of 4 is considered equivocal. 

Once the SLIC scoring system suggests that a specific injury 

should be treated surgically, the surgeon must decide which 

single or combination of surgical approaches to use. Although 

the SLIC classification guides the physician to either 

operative or nonoperative treatment, it does not assist in 

the choice of surgical approach. Currently, there is no evidence-based 

algorithm that would provide surgical treatment 

options and specify which approach should be used. 

This article focuses on the choice of surgical approach once 

the decision to operate has already been made. 

Evidence-based medicine is simply not just the best available 

systematic research, but must also integrate clinical 

expertise and the growing realm of patient preference. A 

systematic review is an exhaustive objective review of the pertinent 

literature around an a priori research question and is 

recognized as the optimal design for literature review. 

Clinical experts can use their experience and knowledge 

to strengthen and optimize research-generated guidelines. 

The Spine Trauma Study Group (STSG) is such a group of 

experts. It is composed of 48 spine surgeons (neurosurgical 

and orthopaedic) who have committed a substantial portion 

of their clinical practices and research to the provision 

of care to spine trauma patients. Finally, and increasingly 

more importantly, surgeons are relying on patient preference 

to guide management recommendations and decisions. 

Patient acceptance of devices such as the halothoracic-vest 

are an example of this. 12 Patients have been 

empowered in the treatment decision armed with information 

around probabilities of outcome, health-related quality 

of life, complications, and care paths. 

Although there is a limited amount of published literature 

that recommends specific surgical approaches for 

certain injuries, the published articles to date each have 1 

or more significant limitations: exclusive reliance on local 

experience; lack of consideration of the global experience 

in the literature; and failure to use well-described 

nomenclature to define the study population. 

There were 2 principle objectives of the present study: 

(1) to undertake a qualitative systematic review of the 

literature on surgical treatment approaches for various 

subaxial cervical spine injuries; and (2) to integrate this 

literature review with the consensus opinion of experts 

from the STSG and the SLIC scoring system to propose 

an evidence-based algorithm to manage these injuries. 

This algorithm would be based on the 3 principal morphologic 

categories, while incorporating the other 2 interrelated 

SLIC categories, namely, neurology and discoligamentous 

complex integrity. By building on the 

foundation of the SLIC scoring system and by adding an 

evidence-based treatment algorithm which specifically 

addresses the optimal surgical approach for subaxial cervical 

injuries, we intend to improve patient outcomes 

and facilitate education and clinical research. 

Methods 

Systematic Review 

For a given question, it is generally accepted that when homogeneous 

level 1 studies are not available, quantitative systematic 

review or meta-analysis cannot be done and a qualitative 

systematic review becomes the design of choice. This particular 

study lends itself well to a qualitative review as we are able to 

apply the various levels of evidence to our broader question 

around appropriate surgical approaches. Therefore, we categorized 

these studies according to their level of evidence and their 

appropriateness to the research question. 

Unique to this qualitative review is the inclusion of biomechanical 

studies that are particularly relevant to the question 

being asked. 

Inclusion or Exclusion Criteria. The criteria used to include 

studies in this review were determined a priori and considered the 

following factors: (1) the population that was studied in the article; 

(2) the intervention that was being reported on; and (3) the 

outcome measures that were reported in the article. To be included 

in this literature review the study had to have adult patients 

(age 16 years) with subaxial cervical traumatic injuries from C3 

to T1 inclusive treated surgically with anterior, posterior, or combined 

anterior and posterior surgical approaches. The study had 

to measure the radiographic and/or clinical success of the treatment 

using validated outcome measures and/or radiographic measures 

and must have described the surgical approach used. 

The most common reasons for exclusion of what appeared 

to be appropriate studies were; failure to specify the surgical 

approach used in treating a cohort of patients, the use of outdated 

surgical techniques, which are no longer used or relevant 

(Cloward Procedure in cervical trauma, sublaminar wires, 

etc.), failure to adequately describe the injury patterns treated, 

and the inclusion of a heterogeneous population, i.e., nontraumatic 

conditions or injuries beyond the subaxial cervical spine. 

Literature Review. A comprehensive literature search was performed 

to identify potential studies including any article with an

2622 Spine • Volume 32 • Number 23 • 2007 

English language abstract. Electronic database searches of 

MEDLINE (1966 to November 2006) and EMBASE (1980 to 

November 2006) were performed using both medical subject 

headings and text word searching. Terms used included fracture, 

cervical, spine fractures, fracture fixation—internal, cervical vertebra. 

A search of the electronic database of CINAHL (1982 to 

November 2006) was conducted using the same text word search. 

Both the Database of Abstracts of Reviews of Effects and the 

Cochrane Database of Systematic Reviews were searched using 

text words. Reference lists from relevant articles were hand 

searched for additional citations. Content experts from the STSG 

were sought and questioned as to possible additional references. 

Study Selection. Two reviewers, both experienced spine surgeons, 

one with advanced epidemiology training, used a standardized 

process to evaluate the eligibility of each article. Articles 

were excluded based on abstract review; otherwise, all the 

remaining studies were assessed using the complete articles. 

Any disagreements between the 2 reviewers were resolved using 

a consensus approach. 

A qualitative synthesis of the published literature was performed 

and the conclusions drawn from this literature were used 

to construct the surgical approaches algorithm. The proposed algorithm, 

including a draft of this article, was then presented to the 

membership of the STSG by email for their opinion on the content 

and face validity of the new evidence-based treatment options. All 

members of the STSG were asked if they agree with the surgical 

approaches recommended by this algorithm and were in agreement 

with the content of the article or if they had major disagreements 

with the algorithm or the article. STSG members were further 

invited to propose changes to the article. After the email 

feedback, the algorithm was presented to the STSG members at 

the STSG semiannual meeting along with several representative 

radiographs and cases. They were discussed to assess the face 

validity, whether the algorithm looks valid and seems reasonable, 

by the STSG members of this algorithm. The consensus of the 

majority of members of the STSG was obtained and none of the 

members had disagreements with the algorithm although significant 

input regarding the methodology was obtained. 

Results 

In the literature search that was performed in November 

2006, we identified 665 articles of potential relevance. The 

study selection process eliminated 526 articles by a review 

of the abstracts alone. An additional 113 articles were excluded 

after a review of their methodology and results sections. 

Most of these were excluded because of relevance 

and methodologic issues. This left a total of 26 articles that 

met all inclusion criteria. Of these 26 articles, 1 article presented 

level I evidence based on its methodology and primary 

question. 13 There were 3 level II articles 14–16 and 7 

level III articles, 12,17–22 which are presented in Table 2. A 

further 15 articles 2–10,23–28 were considered as level IV evidence 

relevant to the question of surgical approach for 

Table 2. Subaxial Cervical Trauma: Surgical Approaches 

Paper Author 

Description 

Level of Evidence of 

Primary Question 

Topic and Conclusions 

Kwon et al 13 

Brodke et al 14 

Do et al 15 

Ianuzzi et al 16 

Prospective randomized trial of anterior 

vs. posterior surgery for unilateral 

facet fractures, appropriately 

powered 

Prospective randomized (by day of 

admission). Trial of anterior vs. 

posterior surgical approach, not 

appropriately powered 

Biomechanics study comparing anterior 

and posterior fixation 

Biomechanics study comparing anterior 

and posterior fixation 

I 

II 

II 

II 

42 patients randomized to anterior or posterior fusion for facet 

fracture without spinal cord injury, no significant difference 

in time to discharge but differences in secondary outcomes 

52 patients with spinal cord injury assigned to anterior or 

posterior surgery with no difference between groups 

Biomechanical comparison of modern anterior/posterior/and 

combined fixation in flexion distraction and corpectomy 

models; anterior plating was inferior to posterior 

Biomechanical study comparing anterior and posterior fixation 

following three column injury; all fixation constructs were 

stiffer than the intact spinal segment 

Beyer et al 12 Retrospective comparative study III 36 patients with unilateral facet injuries treated non-operatively 

and operatively; surgical treatment had better results 

Elgafy et al 17 Retrospective case-control study III 65 patients with cervical fracture dislocations treated with 

posterior fixation; radiographic failure correlated with 

ligamentous bilateral facet subluxations and high degree of 

kyphosis at injury 

Fisher et al 18 Retrospective comparative study III 45 patients with teardrop fractures treated in halo and with 

corpectomy and anterior plate. Improved radiographic 

outcomes in the surgical group 

Hadley et al 19 

Qualitative systematic review of class 

III and IV studies 

III 

Guidelines for management of subaxial cervical injuries 

suggest that anterior and posterior fixations are both valid 

treatment options 

Johnson et al 20 Retrospective case-control study III 87 patients with facet injuries treated with anterior plating: 

radiographic failure tended to occur in patients with 

endplate fractures and facet fractures 

Lifeso and Colucci 21 Retrospective comparative study III 29 retrospective controls and 18 prospective patients 

suggesting anterior fusion has improved outcomes over 

posterior or nonsurgical 

Toh et al 22 Retrospective comparative study III 31 burst fractures and teardrop fractures treated anteriorly and 

posteriorly. Anterior fusion was preferred for spinal canal 

decompression


2623 

Figure 1. Surgical approaches 

algorithm for central cord injuries 

with cervical spondylosis. 

subaxial cervical trauma. One level IV study was a prospective 

cohort study, 3 whereas the remaining 14 were retrospective 

cohort studies. Two of the 7 level III studies were 

retrospective case-control studies, 17,20 1 was a qualitative 

review, 19 and the remaining 4 were retrospective comparative 

studies. 12,18,21,22 

A core group within the STSG after a thorough review 

of the early literature developed the algorithm. This algorithm 

was presented to the membership of the STSG, 

and comments regarding the face and content validity 

were solicited through email and at the semiannual meeting 

of the STSG. 

The 3 main morphologic categories of the SLIC are: 

(1) compression or burst, (2) distraction, and (3) translation 

or rotation. Within each of these 3 categories, the 

interrelated nature of the other 2 categories of SLIC, 

namely, DLC integrity and neurology, are evident. We 

chose to define the segments of the algorithm based on 

the 3 morphologic categories, however, the importance 

of the DLC and neurology remain evident in the body of 

each individual algorithm. 

Central Cord Syndrome in the Presence of 

Cervical Spondylosis 

A unique injury pattern that is encountered with greater 

frequency, given our aging population, is the patient with a 

spondylotic cervical spine that is injured in hyperextension, 

leading to an incomplete central cord injury (Figure 1). 29–34 

Although these injuries will score 0 for both morphology 

(no injury) and DLC (intact), they score 4 for neurology 

(incomplete injury 3; persistent cord compression 1). 

Although several authors have suggested that there may be 

some benefit to early surgical decompression, 35,36 there are 

proponents of initial nonsurgical treatment as long as the 

spine is stable and neurology is static or improving. Specified 

re-evaluation is essential and may dictate delayed or 

late decompression. 29,37–39 

When surgery is indicated after central cord injury in the 

stable spondylotic spine, it is the overall cervical spinal 

alignment and the number of levels affected that determine 

the surgical approach. 30 When the spine is lordotic, and 

particularly when there are multiple levels of compression; 

a posterior approach, either a laminectomy and fusion or a 

cervical laminoplasty are recommended approaches. 28 If 

the spine is neutral or slightly kyphotic, then occasionally, 

after a posterior laminectomy, lordosis may be achieved 

with intraoperative positioning and maintained with posterior 

lateral mass fixation and fusion. 

When the spine is focally kyphotic, particularly when 

there is a fixed kyphosis, or in the presence of anterior 

compression from a disc protrusion or spondylotic bar at 

1 or 2 segments, an anterior surgical decompression (vertebrectomy 

or multiple discectomies) is indicated. 19 Fusion 

and stabilization by means of an anterior strut and 

plate is also supported. 27 

Compression or Burst Injuries 

Subaxial spine injuries where the primary injury is an 

axial load can cause either end-plate compression or 

burst fractures without disruption of the discoligamentous 

complex (Figure 2). These injuries are likely to score 

Figure 2. Surgical approaches algorithm for compression burst 

injuries.


bony fusion. 7,8,14,16,18,27 Rarely is concomitant posterior 

stabilization necessary. 

Both dynamic and static locked cervical plates have 

been described 40,41 with generally theoretical advantages 

for each which leave the decision of which specific 

device to use up to the surgeon. 

Distraction Injuries 

Distraction injuries occur in 2 general patterns; hyperextension, 

often occurring in the stiff spondylotic spine and 

hyperflexion leading to facet subluxations or perched 

facets (Figures 3 and 4). 

Figure 3. Surgical approaches algorithm for hyperextension injuries. 

1 or 2 on the morphology section of SLIC and 0 for DLC 

given that the posterior ligaments are intact. The neurology 

and the presence of residual compression of the spinal 

cord are therefore the strongest determinants of 

treatment. With complete or incomplete neurologic injury 

the SLIC system will add 2, 3, or 4 points to the 2 

morphology points leading to a score of 4 to 6, and thus 

favoring surgery with scores of 5 or greater. 

A number of authors 2,7,14,22,27 have reported on the 

efficacy of anterior decompression and fusion for subaxial 

cervical burst fractures. Although many of the 

above reports include a variety of fracture patterns, it is 

clear that for burst-type fractures, where bone is retropulsed 

into the spinal canal causing neurologic injury, 

the anterior vertebral body resection and stabilization 

provides mechanical reconstitution of the motion segment, 

16 optimal decompression of the neural elements, 22 

and ample local autogenous bone graft from the resected 

vertebral body. In the presence of intact posterior elements, 

the use of an anterior locking plate and strut graft 

provides adequate stability to facilitate long-term stable 

Hyperextension Injury Avulsion Fractures. Classically, 

hyperextension injuries occur in elderly individuals 

with spondylotic or stiff spines (Figure 3). Anterior retropharyngeal 

soft tissue swelling, widening of the disc 

space, high fluid signal in an otherwise degenerative disc 

space along with avulsion fractures of anterior osteophytes, 

or the anteroinferior corner of a vertebral body 

all point to this pattern of injury. Assessing this injury in 

terms of its morphology and DLC status, these injuries 

score 3 for morphology and 2 for DLC with the addition 

of any score resulting from neurologic impairment. The 

vast majority of these injuries require surgical stabilization. 

The surgical approach is informed by the pattern of 

DLC disruption (primarily anterior), and thus most commonly 

an anterior cervical discectomy fusion and plating 

is performed. 2,8,27 This injury seems to occur most commonly 

in the elderly where the spine is spondylotic. If the 

spondylosis is severe or in the case of DISH or ankylosing 

spondylitis, the stiffness of adjacent segments creates 

long lever arms that may best be neutralized with the 

addition of posterior fixation. 24 

Unilateral or Bilateral Facet Subluxation. Distraction injuries 

affecting primarily the posterior elements create a 


algorithm for facet subluxations 

or perched facets.


2625 

spectrum of injury from a simple unilateral facet subluxation 

to bilateral perched facets. In each case, there is a 

varying degree of disruption of not only the posterior 

element ligamentous structures but also the posterior 

anulus of the disc. These injuries are no longer distraction 

and become translational injuries if the facet subluxation 

or perch progresses to a dislocation or becomes 

associated with a fracture. Magnetic resonance imaging 

(MRI) has been shown to be effective in evaluating the 

degree and type of soft tissue disruption associated with 

these injuries. 42–45 

The role of closed reduction and traction before definitive 

surgical stabilization remains controversial. Regardless 

of whether or not a closed reduction is attempted 

the decision as to which surgical approach to 

choose rests on a number of factors. 

When an MRI shows a fragment of disc material displaced 

dorsal to the posterior cortex of the more caudal 

vertebral body, 46 then the surgeons preference should be 

for an anterior approach. 2,7,9,21 This is another example 

of the extent of the DLC disruption (anterior disc protrusion) 

informing the choice of surgical approach. Anterior 

discectomy can decompress the spinal canal directly 

and can then be followed by an anterior closed 

reduction of the facet subluxation (usually achieved by 

placing the patient in some degree of cervical extension 

and by removing any intraoperative traction), inserting 

an interbody graft, and an anterior cervical 

plate. 2,7,8,13,20,21 Ensuring tight, 100% apposition of the 

facets, a trapezoidal interbody graft, and contouring of 

the plate into lordosis will optimize the stability of this 

anterior approach for what is primarily a posterior ligamentous 

injury. Although some biomechanical studies 

have identified the inferiority of anterior fixation when 

compared with posterior fixation in these injuries, most 

studies show that anterior fixation alone for these posterior 

injuries returns the spine to at least the stability of 

the intact motion segment and combined with clinical 

case series provide a compelling case for this treatment 

alternative. 16,41 

When the disc is essentially intact or merely disrupted 

without frank herniation, then the surgeon can make a 

choice either anterior or posterior fixation based on patient 

and surgeon preference. Variables that may influence 

this decision include the available equipment and 

the training and familiarity of the surgeon with each 

approach. From the patients’ perspective, anterior issues 

such as neck scar, the risk of temporary dysphagia or 

hoarse voice, and injury to visceral structures (esophagus) 

may be compared with the additional muscle dissection 

and local wound infection risk found with posterior 

approaches. When a pure ligamentous unilateral or bilateral 

facet subluxation is treated posteriorly, the torn 

ligamentum flavum and any intervening hematoma or 

scar tissue should be resected (flavotomy) before compressing 

to reduce the posterior elements. 47 

Specific to bilateral facet subluxations, however, are 

the findings of a study by Elgafy et al, 17 wherein patients 

with bilateral facet subluxations (perched facets without 

fracture) were found to develop higher degrees of kyphosis 

after posterior instrumented fusion. They, and other 

authors 6,21 postulated that the disruption of the disc that 

occurs with these distraction injuries leads to progressive 

disc space collapse, which the posterior fixation is not 

able to overcome, thus allowing the spinal segment to 

drift into kyphosis. This tendency of posterior fusions to 

lead to kyphosis has been identified by Lifeso and 

Colucci, who recommended anterior plating for these 

injuries. 21 Fehlings et al identified 2 patients with significant 

kyphosis after posterior fixation. 6 The long-term 

clinical significance of segmental kyphosis remains to be 

seen. 

Translation or Rotation Injuries 

Unilateral or Bilateral Facet Fracture Dislocation or Subluxation. 

Translation or rotation injuries score the highest 

number of points on the morphology scale (4 points) 

and almost always are associated with significant ligamentous 

disruption (DLC 2) (Figure 5). Before adding 

the neurology score, these injuries already score 6 on the 

SLIC scale and are thus the most unstable of all cervical 

injuries. Although these injuries may consist of a variety of 

posterior element pathologies spanning the spectrum from 

fracture separation of the lateral mass 25,26 (with translation 

or rotation since an undisplaced lateral mass fracture falls 

within the compression morphology) through completely 

dislocated or locked facets. There may be varying degrees of 

posterior element fracture and comminution of the spinous 

process, lamina, and lateral masses in association with 

burst, sagittal and/or coronal fractures of the vertebral 

body leading to the “so-called” teardrop fracture. 

7,8,16,18,22,27 

All of these injuries therefore exhibit translation of 1 

vertebra relative to an adjacent vertebra. This occurs as 

either pure translation (i.e., bilateral locked facets) or as 

a rotational translation around a single intact facet (i.e., 

displaced unilateral facet fracture or dislocation). The 

principal features that subcategorize and differentiate injuries 

within the translation or rotation group are the 

presence or absence of fractures affecting the vertebral 

body and the presence, severity, and location of residual 

compression of the neural elements. 

End-Plate Compression Fracture With Facet Fracture/ 

Dislocation. The vertebral body fracture may simply be a 

superior end-plate compression fracture that is often difficult 

to see on plain radiographs because of the natural 

shape and slope of the superior endplate of the subaxial 

cervical vertebrae. Once a minimal end-plate compression 

fracture is seen in association with a facet fracture, 

subluxation, or dislocation, this in general is a contraindication 

to anterior alone surgical fixation. Johnson et al 

showed that fully two-thirds of patients with an endplate 

compression fracture who were fused with an anterior 

approach alone developed early mechanical failure



algorithm for translation rotation 

injuries. 

of their fusion. 20 The presence of an end-plate compression 

fracture in association with a rotationally or translationally 

unstable posterior element injury necessitates 

at least a posterior instrumented fusion. If significant 

ligamentous disruption is identified on MRI, if there is 

severe comminution of the facet or lateral mass, or if the 

surgeon is concerned about progressive kyphosis, then a 

combined anterior and posterior fusion may be indicated. 

23 

Vertebral Burst Fracture or Dislocation (Teardrop 

Fracture). More significant anterior vertebral body fractures 

have been described as quadrangular fractures, 48 

teardrop fractures, and burst-fracture dislocations. 

2,16,18,22 These injuries all have in common significant 

posterior element failure (a combination of ligament 

and facet capsule injury in association with varying 

degree of facet and lateral mass fracturing) in association 

with significant fracturing of the vertebral body either 

with large coronal and sagittal fracture lines or a comminuted 

burst-type fractures. The hallmark retrodisplacement 

of the posterior vertebral body cortex relative 

to the cephalad and caudal vertebrae demonstrates the 

high degree of discoligamentous disruption associated 

with this injury and is often the source of residual spinal 

cord compression. Often associated with complete neurologic 

injury, decompression by means of anterior vertebral 

body resection may facilitate neurologic recovery within 

the zone of partial preservation (root recovery). 22 

The majority of these injuries require combined anterior 

and posterior fixation because of the severe degree of 

bony and ligamentous disruption they exhibit. 22,23 Today, 

with improved anesthesia and improved anterior 

locking plates and posterior segmental fixation systems, 

2,3,5–8,16,18,22,27 a combined anterior and posterior 

procedure is not as daunting a task. Cybulski et al reviewed 

a number of patients who failed single approach 

posterior stabilization and required combined anterior 

and posterior stabilization. 23 Before the use of MRI, Cybulski 

et al identified vertebral body retrolisthesis, facet 

dislocation, and shear injury through the disc as indications 

for circumferential (360) fusion. Similarly, De Iure 

et al suggested that any fracture in which an anatomic 

reduction could not be obtained or any traumatic spondylolisthesis 

were indications for 360° fusion. 49 Toh et al 

preferred anterior decompression and fusion for its ability 

to restore the spinal canal diameter and decompress 

neural elements. 22 Within the framework of the SLIC, 

and for this morphologic pattern of injury, neurology 

dictates the need for anterior decompression whereas the 

DLC disruption is the motivation for the posterior and 

anterior fixation. In this severe fracture pattern, our rec-


2627 

ommendation is that a circumferential fusion be performed. 

Unilateral or Bilateral Facet Fracture Dislocations (No 

Vertebral Body Fracture). This injury category contains 

a variety of injuries from the bilateral facet dislocation 

(bilateral locked facets), through a unilateral facet dislocation, 

to a variety of facet, lateral mass, and posterior 

element fractures all with rotational or translational instability. 

There is no consensus in the literature on the 

role and timing of closed reduction as opposed to obtaining 

MRI, or even proceeding to immediate surgical decompression 

in these injuries and this topic is beyond the 

scope of the present article. However, when this controversy 

is resolved, the surgeon is still faced with the question 

of which approach to choose for surgical stabilization, 

since all of these injuries are treated surgically. 

If by means of a prereduction MRI or after neurologic 

deterioration during closed reduction, the surgeon becomes 

aware of a fragment of disc material displaced 

into the spinal canal, then an anterior discectomy, open 

reduction, fusion, and plating becomes necessary. 2,7,9 In 

approximately half of the cases, a closed reduction will 

be successful in reducing the dislocation before surgery. 

50 In the majority of the others, an intraoperative 

reduction performed after the discectomy and decompression 

will achieve anatomic reduction. 9,51 For those 

patients in whom an anterior discectomy and decompression 

have not been successful in reducing the dislocation, 

then a supplemental posterior open reduction 

should be performed. 52 

As is the case in the vast majority of these unilateral or 

bilateral facet fracture dislocations, if there is no evidence 

of a loose fragment of disc in the spinal canal, then 

the surgeon may choose either anterior or posterior fixation. 

The decision between anterior and posterior approach 

when both are viable treatment options is based 

on a number of factors in addition to those factors discussed 

above in the distraction section of this article. 

There are several reports that compare anterior and 

posterior surgery for subaxial cervical trauma, 13,14,53 

only 1 of which has been formally published. Excellent 

results have been reported with both approaches; however, 

each approach has its own unique advantages. The 

posterior approach is biomechanically more robust, particularly 

when used to stabilize primarily posterior injuries. 

15,16 The posterior approach is familiar to surgeons, 

has a high radiographic success rate, and enables direct 

open reduction of dislocated posterior elements and thus 

is favored by many. 3–6,10,25,26 There have been concerns, 

however, regarding the rate of wound infection and the 

ability of posterior alone stabilization to neutralize the 

development of segmental kyphosis as the injured disc 

collapses and settles. 13,21,53 

The anterior approach is favored by some because the 

traumatized patient does not have to be positioned 

prone, disc herniations can be directly removed, thus 

decompressing the canal, and the high fusion rate and 

maintenance of segmental lordosis are attractive. 

2,7,9,13,21 The criticism of the anterior approach for 

cervical subaxial trauma originates from its biomechanical 

inferiority when compared with posterior fixation, 

although it is still stiffer than an intact spine segment. 

15,16 Other concerns are the complications of dysphagia, 

hoarse voice, and early radiographic failure 

when used in the presence of end-plate compression fractures 

and very comminuted or large facet fracture fragments. 

13,20 Although the guidelines described by Spector 

et al relate to the prediction of failure of nonsurgical 

treatment, likely a similar measurement of the size of the 

facet fracture fragment would also predict the success of 

stand-alone anterior discectomy and fusion for facet 

fracture dislocations. 54 

The Influence of the Discoligamentous Complex 

There are several morphologic categories for which the 

pattern and extent of DLC disruption is the critical factor 

in determining the surgical approach within this algorithm. 

The hyperextension or posterior ligament injuries 

are often best treated by an approach from the direction 

of maximal soft tissue disruption. The extent of disc disruption 

and potential displacement can also define the 

primary surgical approach in the case of facet dislocations 

as has been discussed above. The reliability and 

validity of diagnosing injuries to the DLC are currently 

undergoing prospective study. 

The Influence of Neurology 

In the majority of cases where there is a spinal cord injury, 

complete or incomplete, surgery will likely be performed. 

In many of these cases, effective decompression 

of the spinal canal is a primary goal of treatment, if not to 

obtain distal recovery, then to achieve local root or segmental 

recovery. The neurology guides the approach in 

the case of the incomplete spinal cord injury without 

instability. Neurology also influences the surgical approach 

when there is cord compression from a vertebral 

body fracture, anterior traumatic disc protrusion, or a 

facet fragment causing foraminal root compression. 

Discussion 

Spinal injuries occur in an estimated 150,000 people per 

year in North America, 11,000 of which have concomitant 

spinal cord injuries (1 out of every 25,000 people 

annually). 19,55 The exponential increase in the technology 

available for surgical fixation in the subaxial spine 

has not been paralleled by the evolution of guidelines or 

evidence-based recommendations on when to use this 

technology. One of the obstructions to the development 

of evidence-based consensus guidelines has been the 

largely descriptive and nonstandardized classification of 

injuries to the subaxial cervical spine. 

The SLIC severity scale, based on 3 components of 

injury (morphology, neurology, and DLC disruption), 

which, by consensus, represent major and largely independent 

determinants of prognosis and management, is 

an attempt to characterize injuries based on injury mor-


phology and clinical status. 11 By building an algorithm 

for surgical approach on the interrelated components of 

the SLIC system, we feel that some clarity can be added 

to not only what to call an injury, but also what reasonable 

treatment options are available. 

The authors acknowledge that there are many injury 

patterns that can be managed nonsurgically and the SLIC 

classification will identify these. Our algorithm commences 

when the decision to operate has been made. It is 

also acknowledged by the authors that individual patterns 

of injury and unique patient factors may influence 

the choice of treatment to the point where it may appropriately 

deviate from the options outlined in this article. 

No single algorithm or treatment approach can be adhered 

to rigidly in all situations and this report is simply 

a guideline to assist in the decision-making process. 

We have proposed anterior decompression, fusion, 

and plating for most burst fractures with neurologic impairment. 

We have also outlined the 2 major surgical 

treatment options for the spondylotic cervical spine with 

a central cord injury and ongoing spinal cord compression. 

The majority of hyperextension injuries are treated 

with anterior fixation, which in the severely ankylosed 

spine (DISH or ankylosing spondylitis) should probably 

be supplemented with posterior fixation. There are a 

very few posterior distraction injuries that have a concomitant 

disc herniation and require anterior discectomy, 

fusion, and plating. However, for the remaining 

majority of these facet subluxations, the surgeon is free 

(and supported by current literature) to choose either 

anterior or posterior stabilization. 

The most complex and unstable group of injuries are 

the translation or rotation injuries where surgical approach 

decisions are made based on the involvement of 

the vertebral body (teardrop or compression fractures) 

and the presence of a disc herniation. Although many of 

the compression and distraction injuries can be managed 

with anterior surgery alone, injuries in the translation or 

rotation category are more commonly treated with posterior 

and circumferential fusion. Many of the most unstable 

injuries, such as teardrop fractures (translation 

with a vertebral body fracture) or bilateral facet fracture 

dislocations in which either closed or anterior open reduction 

are not successful in achieving anatomic reduction 

are best managed with a circumferential anterior 

and posterior fusion. Less severe injuries such as the unilateral 

facet fracture dislocation may be managed with 

either posterior or anterior approaches alone. 

In summary, we propose an algorithm for surgical 

approaches to the traumatized subaxial cervical spine, 

which is based on the morphologic categories of the SLIC 

classification system and severity scale. The evidencebased 

nature of this algorithm emanates from its derivation 

through an exhaustive systematic literature review, 

the consensus of experts, and suggested inclusion of patient 

preference based on informed probabilities from the 

literature. Although the face and content validity of this 

algorithm seems satisfactory, it requires more robust criterion 

related validity and generalizability evaluation before 

it can be widely implemented. This algorithm is not 

intended to be a stagnant paradigm. Further literature 

will certainly refine the factors that lead to 1 approach as 

opposed to another and will be added over time to 

strengthen the classification leading to improved patient 

care. 

Key Points 

● An algorithm is proposed to guide the choice of 

surgical approaches to the traumatized subaxial 

cervical spine using the categories of burst, distraction, 

and translation. 

● The algorithm is based on a systematic literature 

review, the consensus of experts, and patient preference. 

● Burst or compression injuries and distraction injuries 

are more likely to be treated with a single 

anterior approach. 

● Translation or rotation injuries may more commonly 

be approached posteriorly or with combined 

anterior and posterior surgery. 

References 

1. Glaser JA, Jaworski BA, Cuddy BG, et al. Variation in surgical opinion 

regarding management of selected cervical spine injuries. A preliminary 

study. Spine 1998;23:975–82. 

2. Aebi M, Zuber K, Marchesi D. Treatment of cervical spine injuries with 

anterior plating. Indications, techniques, and results. Spine 1991;16:S38– 

S45. 

3. Anderson PA, Henley MB, Grady MS, et al. Posterior cervical arthrodesis 

with AO reconstruction plates and bone graft. Spine 1991;16:S72–S79. 

4. Cooper PR, Cohen A, Rosiello A, et al. Posterior stabilization of cervical 

spine fractures and subluxations using plates and screws. Neurosurgery 

1988;23:300–6. 

5. Ebraheim NA, Rupp RE, Savolaine ER, et al. Posterior plating of the cervical 

spine. J Spinal Disord 1995;8:111–15. 

6. Fehlings MG, Cooper PR, Errico TJ. Posterior plates in the management of 

cervical instability: long-term results in 44 patients. J Neurosurg 1994;81: 

341–9. 

7. Goffin J, Plets C, Van den BR. Anterior cervical fusion and osteosynthetic 

stabilization according to Caspar: a prospective study of 41 patients with 

fractures and/or dislocations of the cervical spine. Neurosurgery 1989;25: 

865–71. 

8. Lambiris E, Zouboulis P, Tyllianakis M, et al. Anterior surgery for unstable 

lower cervical spine injuries. Clin Orthop Relat Res 2003;61–9. 

9. Razack N, Green BA, Levi AD. The management of traumatic cervical bilateral 

facet fracture-dislocations with unicortical anterior plates. J Spinal Disord 

2000;13:374–81. 

10. Shapiro S, Snyder W, Kaufman K, et al. Outcome of 51 cases of unilateral 

locked cervical facets: interspinous braided cable for lateral mass plate fusion 

compared with interspinous wire and facet wiring with iliac crest. J Neurosurg 

1999;91:19–24. 

11. Vaccaro AR, Hurlbert RJ, Fisher CG, et al. The sub-axial cervical spine 

injury classification system (SLIC): a novel approach to recognize the importance 

of morphology, neurology and integrity of the disco-ligamentous complex. 

Spine. 2007;32:2365–74. 

12. Beyer CA, Cabanela ME, Berquist TH. Unilateral facet dislocations and 

fracture-dislocations of the cervical spine. J Bone Joint Surg Br 1991;73: 

977–81. 

13. Kwon BK, Boyd M, Fisher CG, et al. A prospective randomized controlled 

trial comparing anterior versus posterior stabiliztion for unilateral facet injuries 

of the cervical spine. Presented at: Abstracts of the 12th International 

Meeting on Advanced Spine Techniques (IMAST), Banff, Alberta, July 7, 

2005. 

14. Brodke DS, Anderson PA, Newell DW, et al. Comparison of anterior and


2629 

posterior approaches in cervical spinal cord injuries. J Spinal Disord Tech 

2003;16:229–35. 

15. Do KY, Lim TH, Won YJ, et al. A biomechanical comparison of modern 

anterior and posterior plate fixation of the cervical spine. Spine 2001;26: 

15–21. 

16. Ianuzzi A, Zambrano I, Tataria J, et al. Biomechanical evaluation of surgical 

constructs for stabilization of cervical teardrop fractures. Spine J 2006;6: 

514–23. 

17. Elgafy H, Fisher CG, Zhao Y, et al. The radiographic failure of single segment 

posterior cervical instrumentation in traumatic cervical flexion distraction 

injuries. Top Spinal Cord Inj Rehabil 2006;12:20–9. 

18. Fisher CG, Dvorak MF, Leith J, et al. Comparison of outcomes for unstable 

lower cervical flexion teardrop fractures managed with halo thoracic vest 

versus anterior corpectomy and plating. Spine 2002;27:160–6. 

19. Hadley MN, Walters BC, Grabb PA, et al. Guidelines for the management 

of acute cervical spine and spinal cord injuries. Clin Neurosurg 2002;49: 

407–98. 

20. Johnson MG, Fisher CG, Boyd M, et al. The radiographic failure of single 

segment anterior cervical plate fixation in traumatic cervical flexion distraction 

injuries. Spine 2004;29:2815–20. 

21. Lifeso RM, Colucci MA. Anterior fusion for rotationally unstable cervical 

spine fractures. Spine 2000;25:2028–34. 

22. Toh E, Nomura T, Watanabe M, et al. Surgical treatment for injuries of the 

middle and lower cervical spine. Int Orthop 2006;30:54–8. 

23. Cybulski GR, Douglas RA, Meyer PR Jr, et al. Complications in threecolumn 

cervical spine injuries requiring anterior-posterior stabilization. 

Spine 1992;17:253–6. 

24. Einsiedel T, Schmelz A, Arand M, et al. Injuries of the cervical spine in 

patients with ankylosing spondylitis: experience at two trauma centers. 

J Neurosurg Spine 2006;5:33–45. 

25. Kotani Y, Abumi K, Ito M, et al. Cervical spine injuries associated with 

lateral mass and facet joint fractures: new classification and surgical treatment 

with pedicle screw fixation. Eur Spine J 2005;14:69–77. 

26. Levine AM, Mazel C, Roy-Camille R. Management of fracture separations 

of the articular mass using posterior cervical plating. Spine 1992;17:S447– 

S454. 

27. Ripa DR, Kowall MG, Meyer PR Jr, et al. Series of ninety-two traumatic 

cervical spine injuries stabilized with anterior ASIF plate fusion technique. 

Spine 1991;16:S46–S55. 

28. Uribe J, Green BA, Vanni S, et al. Acute traumatic central cord syndrome– 

experience using surgical decompression with open-door expansile cervical 

laminoplasty. Surg Neurol 2005;63:505–10. 

29. Dvorak MF, Fisher CG, Hoekema J, et al. Factors predicting motor recovery 

and functional outcome after traumatic central cord syndrome: a long-term 

follow-up. Spine 2005;30:2303–11. 

30. Harrop JS, Sharan A, Ratliff J. Central cord injury: pathophysiology, management, 

and outcomes. Spine J 2006;6:S198–S206. 

31. Tow AM, Kong KH. Central cord syndrome: functional outcome after rehabilitation. 

Spinal Cord 1998;36:156–60. 

32. Waters RL, Adkins RH, Sie IH, et al. Motor recovery following spinal cord 

injury associated with cervical spondylosis: a collaborative study. Spinal 

Cord 1996;34:711–15. 

33. Wilkinson HA. Central cord syndrome. J Neurosurg 2002;97:158–9. 

34. Yamazaki T, Yanaka K, Fujita K, et al. Traumatic central cord syndrome: 

analysis of factors affecting the outcome. Surg Neurol 2005;63:95–9. 

35. Chen TY, Dickman CA, Eleraky M, et al. The role of decompression for 

acute incomplete cervical spinal cord injury in cervical spondylosis. Spine 

1998;23:2398–403. 

36. Guest J, Eleraky MA, Apostolides PJ, et al. Traumatic central cord syndrome: 

results of surgical management. J Neurosurg 2002;97:25–32. 

37. Ishida Y, Tominaga T. Predictors of neurologic recovery in acute central cervical 

cord injury with only upper extremity impairment. Spine 2002;27:1652–8. 

38. McKinley W, Meade MA, Kirshblum S, et al. Outcomes of early surgical 

management versus late or no surgical intervention after acute spinal cord 

injury. Arch Phys Med Rehabil 2004;85:1818–25. 

39. Pollard ME, Apple DF. Factors associated with improved neurologic outcomes 

in patients with incomplete tetraplegia. Spine 2003;28:33–9. 

40. Brodke DS, Klimo P Jr, Bachus KN, et al. Anterior cervical fixation: analysis 

of load-sharing and stability with use of static and dynamic plates. J Bone 

Joint Surg Am 2006;88:1566–73. 

41. Dvorak MF, Pitzen T, Zhu Q, et al. Anterior cervical plate fixation: a biomechanical 

study to evaluate the effects of plate design, endplate preparation, 

and bone mineral density. Spine 2005;30:294–301. 

42. Geck MJ, Yoo S, Wang JC. Assessment of cervical ligamentous injury in 

trauma patients using MRI. J Spinal Disord 2001;14:371–7. 

43. Halliday AL, Henderson BR, Hart BL, et al. The management of unilateral 

lateral mass/facet fractures of the subaxial cervical spine: the use of magnetic 

resonance imaging to predict instability. Spine 1997;22:2614–21. 

44. Klein GR, Vaccaro AR, Albert TJ, et al. Efficacy of magnetic resonance 

imaging in the evaluation of posterior cervical spine fractures. Spine 1999; 

24:771–4. 

45. Vaccaro AR, Madigan L, Schweitzer ME, et al. Magnetic resonance imaging 

analysis of soft tissue disruption after flexion-distraction injuries of the subaxial 

cervical spine. Spine 2001;26:1866–72. 

46. Vaccaro AR, Falatyn SP, Flanders AE, et al. Magnetic resonance evaluation 

of the intervertebral disc, spinal ligaments, and spinal cord before and after 

closed traction reduction of cervical spine dislocations. Spine 1999;24: 

1210–17. 

47. Ludwig SC, Vaccaro AR, Balderston RA, et al. Immediate quadriparesis after 

manipulation for bilateral cervical facet subluxation. A case report. J Bone 

Joint Surg Am 1997;79:587–90. 

48. Favero KJ, Van Peteghem PK. The quadrangular fragment fracture. Roentgenographic 

features and treatment protocol. Clin Orthop Relat Res 1989; 

239:40–6. 

49. De Iure F, Scimeca GB, Palmisani M, et al. Fractures and dislocations of the 

lower cervical spine: surgical treatment. A review of 83 cases. Chir Organi 

Mov 2003;88:397–410. 

50. Hadley MN, Fitzpatrick BC, Sonntag VK, et al. Facet fracture-dislocation 

injuries of the cervical spine. Neurosurgery 1992;30:661–6. 

51. Vital JM, Gille O, Senegas J, et al. Reduction technique for uni- and biarticular 

dislocations of the lower cervical spine. Spine 1998;23:949–54. 

52. Payer M. Immediate open anterior reduction and antero-posterior fixation/ 

fusion for bilateral cervical locked facets. Acta Neurochir (Wien) 2005;147: 

509–13. 

53. Roberto RF, Porter S, Hart R. Is anterior stabilization of cervical fracture 

dislocations associated with higher complication rates than posterior stabilization? 

In: Abstracts of the 34th Annual Meeting of the Cervical Spine 

Research Society. San Francisco, CA: Cervical Spine Research Society; December 

1, 2006: 40–1. 

54. Spector LR, Kim DH, Affonso J, et al. Use of computed tomography to 

predict failure of nonoperative treatment of unilateral facet fractures of the 

cervical spine. Spine 2006;31:2827–35. 

55. Lowery DW, Wald MM, Browne BJ, et al. Epidemiology of cervical spine 

injury victims. Ann Emerg Med 2001;38:12–16.

The Surgical Approach to Subaxial Cervical Spine Injuries

Create successful ePaper yourself

Delete template?

Save as template?