The case for early treatment of dislocations of the cervical spine with cord involvement sustained playing rugby

Open Reduction in Traumatic Cervical Facet Dislocation Does Not Delay Time to Treatment

Background Cervical facet dislocation is a serious injury that can result in permanent neurologic damage. Current guidelines recommend immediate closed reduction of cervical dislocations, though the efficacy of this practice remains a debate. This study aims to evaluate whether immediate open reduction and fixation of cervical dislocations offer equal or better outcomes for patients and limit the need for follow-up operations. Methods This is a retrospective study including patients who presented to the emergency department of a single institution from 2008 to 2023 with cervical facet dislocation. Patients were divided into groups based on initial treatment: either open or closed reduction. Time to surgery was calculated as the time between arrival to the ED and incision time in the OR. Primary outcomes were improvement in motor and sensory deficits at six-week post-operative follow-up. Results There were 31 patients who met the inclusion criteria. Time to treatment did not differ significantly between the open versus closed reduction groups. There were no differences between groups in improvement in motor function, sensory function, or pain at the six-week follow-up. All patients treated with initial closed reduction ultimately required surgical stabilization. Conclusions Open reduction as a first-line treatment did not increase the time to treatment for patients with cervical facet dislocations. Patients had equivalent functional outcomes in both treatment groups. The findings suggest that current practice guidelines may delay definitive treatment without improving patient safety or outcomes.

Awake Early Manual Reduction Is Highly Effective for Subaxial Cervical Spine Dislocation

Introduction

Guidelines published in 2013 recommend early closed reduction for cervical spine dislocation. There are two types of closed reduction: manual reduction and traction. Manual reduction can be performed early. In addition, it can correct rotation and requires a short time for complete reduction. We perform manual reduction for cervical spine dislocation. This study aimed to evaluate early manual reduction's success rate and safety for cervical dislocation. We also examined the relationship between time to reduction and improvement in paralysis.

Methods

This retrospective cohort study included 361 patients with cervical spine injuries treated at our hospital between July 2010 and December 2021. We assigned patients to the early group if the time from injury to reduction was ≤6 hours and to the late group if >6 hours. We performed awake manual reduction on the patients. Furthermore, we compared reduction's success rate and safety, including neurological outcomes.

Results

Overall, 46 patients were included in the study: 31 and 15 in the early and late groups, respectively. The success rate of reduction was 93%, and no neurological complications from reduction were observed. The neurological outcomes and reduction success rates were significantly superior in the early group than in the late group.

Conclusions

Neurological outcomes were significantly superior when reduction was performed within 6 hours than after 6 hours. Manual reduction can be performed early, safely, and easily. It is effective for cervical spine dislocation requiring early reduction for an excellent neurologic prognosis.

Optimal Timing in Cervical Spinal Cord Injury: A Comprehensive Meta-Analysis of Ultra-Early Surgical Intervention Within Five Hours

The optimal timing of surgery for cervical spinal cord injuries (SCI) and its impact on neurological recovery continue to be subjects of debate. This systematic review and meta-analysis aims to consolidate and assess the existing evidence regarding the efficacy of ultra-early decompression surgery in improving clinical outcomes after cervical SCI. A search was conducted in PubMed, Embase, Cochrane, and CINAHL databases from inception until September 18, 2023, focusing on human studies. The groups were categorized into ultra-early decompression (decompression surgery ≤ 5 hours post-injury) and a control group (decompression surgery between 5-24 hours post-injury). A random effects meta-analysis was performed on all studies using R Studio. Outcomes were reported as effect size (OR, treatment effect, and 95% CI. Of the 140 patients, 63 (45%) underwent decompression ≤ 5 hours, while 77 (55%) underwent decompression > 5 hours post-injury. Analysis using the OR model showed no statistically significant difference in the odds of neurological improvement between the ultra-early group and the early group (OR = 1.33, 95% CI: 0.22-8.18, p = 0.761). This study did not observe significant neurological improvement among cervical SCI patients who underwent decompression within five hours. Due to the scarcity of literature on the ultra-early decompression of cervical SCI, this study underscores the necessity for additional investigation into the potential benefits of earlier interventions for cervical SCI to enhance patient outcomes.

Sequential treatment of concomitant odontoid fracture and lower cervical fracture-dislocation: A case report

INTRODUCTION AND IMPORTANCE

To report the sequential treatment of a Type II odontoid fracture combined with a severe lower cervical (C6-7) fracture-dislocation featuring bilateral facet joint interlocking.

CASE PRESENTATION

A 58-year-old male who had suffered an injury in a car accident, He presented neck pain and extremity paralysis. His neurological function was classified as per the American Spinal Injury Association (ASIA) impairment scale as Grade A, indicating complete deficits below the C6 spinal cord level. A cervical CT scan and magnetic resonance image showed a type II odontoid fracture, C6 slipped anteriorly, C6-7 bilateral facet joint fracture and interlocking, slightly compression change of C7 upper endplate.

CLINICAL DISCUSSION

Emergency closed reduction using cranial tong traction was success 6 h after the injury. A subsequent CT scan proved the successful reduction of bilateral facet joint dislocations and the odontoid fracture. After careful overall assessment, anterior cervical decompression and fusion (ACDF) was performed at C5-6 and C6-7 segments three days later，while odontoid fracture was treated conservatively. At the 4 months follow-up, a CT scan demonstrated solid bone fusion at C5-6, C6-7 segments, along with successful healing at the odontoid fracture site. However, spinal cord was necrosis at C5-7 segments, and the patient's neurological function had no improvement.

CONCLUSION

The initial closed reduction could restore the alignment and preliminary stability of cervical spine at sub-axial cervical fracture-dislocation segment as well as displaced odontoid fracture. This timely and effective closed reduction significantly diminished sequential surgical trauma and mitigated associated risks.

Closed reduction of fracture-dislocation of the sub-axial cervical spine with Gardner-Wells tongs. Technical note

Study design

Technical note.

Purpose

To provide a technical description of the placement of Gardner-Wells tongs and the performance of awake cranio-cervical traction to reduce AO type C injuries of the sub-axial cervical spine with Gardner-Wells tongs.

Methods

In this technical note, the authors present the indications, the contraindications, the pull-out of the pins, a detailed description of the technique for its proper placement, traction reduction technique, reduction maneuvers, complications and post-reduction care.

Results

Awake reduction of AO type C injuries of the sub-axial cervical spine can be successfully performed using Gardner-Wells tongs.

Conclusions

There is sufficient evidence to recommend the use of cranio-cervical traction in these vertebral injuries; however, we lack a detailed technical note to guide its proper placement.

Bilateral Cervical Facet Dislocation Due to Catastrophic Shallow Water Diving: A Case Report

Bilateral cervical facet dislocation is a rare injury resulting from headfirst shallow water diving accidents. Accurate diagnosis, prompt management, precise intervention, and aggressive rehabilitation can lead to a favourable neurologic and functional outcome for cervical spine injuries. In this case, we present a young adolescent patient who experienced bilateral facet dislocation of C4/C5, resulting in incomplete central cord syndrome neurological deficits (American Spinal Injury Association (ASIA) Impairment Scale C) due to a dangerous shallow water diving accident. The patient subsequently underwent emergency posterior instrumentation and decompression for stabilization and rehabilitation. Immediately following the surgery, he exhibited substantial neurologic recovery and was able to walk independently after six months. This case is unique not only for its rarity but also because it involved a young adolescent, highlighting the need for increased awareness and preventive measures to reduce the risk of dangerous shallow water diving accidents.

Immediate Closed Reduction Technique for Cervical Spine Dislocations

STUDY DESIGN

Retrospective study.

PURPOSE

This research aimed to assess the clinical outcomes of patients with traumatic cervical spine dislocation who underwent closed reduction employing our approach.

OVERVIEW OF LITERATURE

Bedside closed reduction is the quickest procedure for repairing traumatic cervical spine dislocations; nevertheless, it also possesses the risk of neurological deterioration.

METHODS

For closed reduction, the patient's head was elevated on a motorized bed, the cervical spine was placed at the midline, traction of 10 kg was applied, the motorized bed was gradually returned to a flat position, the head was lifted off the bed, and the cervical spine was slowly adjusted to a flexed position. The weight of traction was elevated by 5-kg increments until the positional shift was attained. Subsequently, the bed was gradually tilted while traction was applied again to return the cervical spine to the midline position.

RESULTS

Of the 43 cases of cervical spine dislocation, closed reduction was carried out in 40 cases, of which 36 were successful. During repositioning, three patients experienced a temporary worsening of their neck pain and neurological symptoms that enhanced when the cervical spine was flexed. Closed reduction was conducted while the patient was awake; nevertheless, sedation was needed in three cases. Among the 24 patients whose pretreatment paralysis had been characterized by American Spinal Injury Association Impairment Scale (AIS) grades A-C, seven patients (29.2%) demonstrated an enhancement of two or more AIS grades at the last observation.

CONCLUSIONS

Our closed reduction approach safely repaired traumatic cervical spine dislocations.

Updates in the Early Management of Acute Spinal Cord Injury

Spinal cord injury (SCI) is a leading cause of disability worldwide, and effective management is necessary to improve clinical outcomes. Many long-standing therapies including early reduction and spinal cord decompression, methylprednisolone administration, and optimization of spinal cord perfusion have been around for decades; however, their efficacy has remained controversial because of limited high-quality data. This review article highlights studies surrounding the role of early surgical decompression and its role in relieving mechanical pressure on the microvascular circulation thereby reducing intraspinal pressure. Furthermore, the article touches on the current role of methylprednisolone and identifies promising studies evaluating neuroprotective and neuroregenerative agents. Finally, this article outlines the expanding body of literature evaluating mean arterial pressure goals, cerebrospinal fluid drainage, and expansive duroplasty to further optimize vascularization to the spinal cord. Overall, this review aims to highlight evidence for SCI treatments and ongoing trials that may markedly affect SCI care in the near future.

Safety of early posterior fusion surgery without endovascular embolization for asymptomatic vertebral artery occlusion associated with cervical spine trauma

PURPOSE

Vertebral artery occlusion (VAO) is an increasingly recognized complication of cervical spine trauma. However, the management strategy of VAO remains heavily debated. Therefore, the aim of this retrospective study was to investigate the safety of early fusion surgery for traumatic VAO.

METHODS

This study included a total of 241 patients (average age 64.7 years; 201 men) who underwent early surgical treatment for acute cervical spine injury between 2012 and 2019. The incidence of VAO, cerebral infarction rates, the recanalization rates, and cerebral thromboembolism after recanalization were retrospectively analyzed.

RESULTS

VAO occurred in 22 patients (9.1%). Of the 22 patients with VAO, radiographic cerebral infarction was detected in 4 patients (21.1%) at initial evaluation, including 1 symptomatic medullar infarction (4.5%) and 3 asymptomatic cerebrum infarctions. A patient who experienced right medullar infarction showed no progression of the neurologic damage. Follow-up imaging revealed that the VAOs of 9 patients (40.9%) were recanalized, and the recanalization did not correlate with clinical adverse outcomes. The arteries of the remaining 13 (59.1%) patients remained occluded and clinically silent until the final follow-up (mean final follow-up 33.0 months).

CONCLUSION

Despite the lack of a concurrent control group with preoperative antiplatelet therapy or endovascular embolization for VAO, our results showed low symptomatic stroke rate (4.5%), high recanalization rate (40.9%), and low mortality rate (0%). Therefore, we believe that the indication for early stabilization surgery as management strategy of asymptomatic VAO might be one of the safe and effective treatment options for prevention of symptomatic cerebral infarction.

The surgical treatment of subaxial acute cervical spine facet dislocations in adults: a systematic review and meta-analysis

Adult cervical spine traumatic facet joint dislocations occur when excessive traumatic forces displace the vertebrae's facets, leading to loss of joint congruence. Reduction requires either cranial traction or open surgical procedures. This study aims to appraise the effects of different surgical techniques in the treatment of subaxial cervical spine acute traumatic facet blocks in adults. This study was based on a systematic literature review and meta-analysis, registered in Prospero (CRD42021279249). The PICO question was composed of adults with acute cervical spine traumatic facet dislocations submitted to anterior or posterior surgical approaches, associated or not with cranial traction for reduction. Each surgical technique was compared to the other. The primary clinical outcomes included neurological improvement or worsening and surgical success/failure rates. The anterior approach without cranial traction was efficient in reducing facet displacements. Skull traction was an efficient and immediate method to achieve spine dislocation reductions. Differences were not present among techniques regarding neurological improvement. There were no surgical failures in patients operated on via the posterior approach. The need to decompress and stabilize the cervical spine can be achieved by anterior or posterior surgical approaches, and there is no clear answer as to which initial approach is superior to the other.

Rare case of real-time observation of paralytic deterioration after cervical dislocation in the hyperacute phase

Background

There have been no prior reports of real-time detailed records leading to complete quadriplegia immediately after fracture dislocation in high-energy trauma. Here, we report a case of cervical dislocation in which the deterioration to complete motor paralysis (modified Frankel B1) and complete recovery (Frankel E) could be monitored in real time after reduction in the hyperacute phase.

Case presentation

A 65-year-old man was involved in a car accident and sustained a dislocation at the C5/6 level (Allen–Ferguson classification: distractive flexion injury stage IV). His paralysis gradually deteriorated from Frankel D to C 2 hours after the injury and from Frankl C to B 5 hours after the injury. His final neurological status immediately before reduction was Frankel B1 (complete motor paralysis with sensation only in the perianal region). Reduction was completed within 6 h and 5 min after injury, and spinal fusion was subsequently performed. The patient exhibited rapid motor recovery immediately after surgery, and was able to walk independently on postoperative day 14.

Conclusions

This case suggests that there is a mixture of cases in which the spinal cord has not been catastrophically damaged, even if the patient has complete motor paralysis. Prompt reduction has the potential to improve neurological function in such cases.

The impact of helicopter emergency medical services and craniocervical traction on the early reduction of cervical spine dislocation in a rural area of Japan

BACKGROUND

Several studies have shown an association between achieving decompression of the spinal cord within a few hours and neurological recovery, even in patients with complete paralysis due to cervical spine dislocation. This study aimed to clarify the impact of helicopter emergency medical services (HEMSs) and craniocervical traction on the rapid reduction of lower cervical spine dislocation in rural Japan.

METHODS

The success rate of and factors inhibiting closed reduction, the time from injury to reduction and the functional prognosis of lower cervical spine dislocations treated between July 2012 and February 2020 were retrospectively analysed.

RESULTS

Fourteen patients were transported by HEMS (group H), seven by ambulance (group A) and two by themselves. Although the average traveled distance and injury severity score were significantly higher in group H (64.5 km, 28.0) than in group A (24.7 km, 18.6), there was no significant difference in the average time to admission or the time to initiation of craniocervical traction after admission between groups H (159.4 min, 52.2 min) and A (163.6 min, 53.2 min). The success rate of closed reduction was 95%, and neurological deterioration was not observed in any cases. The average traction time and weight for reduction were 30.3 min and 16.3 kg, respectively. Body size and fracture-dislocation type did not significantly affect the traction time or weight. The rate of reduction within 4 h after injury was higher in group H (79%) than in group A (33%). Inner fixations were treated an average of 5.7 days after admission. After treatment, three of nine AIS A patients recovered the ability to walk, and all three patients underwent successful closed reduction within 4 h after injury.

CONCLUSION

HEMS and highly successful closed reduction contributed to the early reduction of cervical spine dislocation and can potentially improve complete paralysis.

Early Decompression and Short Transport Time After Traumatic Spinal Cord Injury are Associated with Higher American Spinal Injury Association Impairment Scale Conversion

STUDY DEIGN

Retrospective cohort study.

OBJECTIVES

This retrospective cohort study aims to determine the association of early decompressive surgery and the impact of transport time on the neurological outcomes of traumatic spinal cord injury (tSCI) patients.

SUMMARY OF BACKGROUND DATA

tSCI is a catastrophic event that may result in permanent disability or loss of function. To date, there remains significant controversy over the optimal time for surgical decompression in tSCI patients. The aim of this study is to evaluate the neurological outcomes of tSCI patients undergoing early versus late surgical decompression and the impact of transport time on neurological outcomes.

METHODS

Data from 84 patients with tSCI requiring surgical decompression was collected. Regression analysis was used to establish time to decompression classification cutoffs. Patients were classified into the following subgroups: 0 to 12 or >12 hours as a factor of the total or admitting hospital time to decompression. The change in American Spinal Injury Association Impairment (AIS) Grade from admission to discharge was determined. Additionally, the effect of transport time on conversion of AIS grade was assessed as patients were grouped into transport times of <6 or >6 hours.

RESULT

Among the time to decompression subgroups there were no significant differences (P > 0.05) in confounding factors such as age, injury severity, and AIS grade. Patients who received decompression within 0 to 12 hours were associated with significantly (P < 0.0001) higher average improvements in ASIA grade (0.76). Patient transport times <6 hours were associated with significantly (P = 0.004) higher conversion of AIS grade to less impaired states.

CONCLUSION

The present study suggests an association of decompression within 12 hours and short transport times (<6 hours) with significant improvements in neurological outcomes.Level of Evidence: 4.

Sub-Axial Cervical Facet Dislocation: A Review of Current Concepts

Cervical facet dislocation is a serious injury that carries risks of short- and long-term morbidity. The optimal management of these injuries remains controversial with the ongoing debate regarding indications and requirements for closed reduction, timing, type of surgical approach and method of fixation. This review gives an update on the relevant anatomy, classification systems for sub-axial cervical facet dislocation and an overview of the current concepts regarding their management, including surgical approaches and the choice of implants.

Early Management of Cervical Spine Trauma: WFNS Spine Committee Recommendations

Epidemiology, prevention, early management of cervical spine trauma and it's reduction are the objectives of this review paper. A PubMed and MEDLINE search between 2009 and 2019 were conducted using keywords. Case reports, experimental studies, papers other than English language and and unrelated studies were excluded. Up-to-date information on epidemiology of spine trauma, prevention, early emergency management, transportation, and closed reduction were reviewed and statements were produced to reach a consensus in 2 separate consensus meeting of World Federation of Neurosurgical Societies (WFNS) Spine Committee. The statements were voted and reached a positive or negative consensus using Delphi method. Global incidence of traumatic spinal injury is higher in low- and middle-income countries. The most frequent reasons are road traffic accidents and falls. The incidence from low falls in the elderly are increasing in high-income countries due to ageing populations. Prevention needs legislative, engineering, educational, and social efforts that need common efforts of all society. Emergency care of the trauma patient, transportation, and in-hospital acute management should be planned by implementing detailed protocols to prevent further damage to the spinal cord. This review summarizes the WFNS Spine Committee recommendations on epidemiology, prevention, and early management of cervical spine injuries.

Predictive factors for irreversible motor paralysis following cervical spinal cord injury

STUDY DESIGN

A retrospective observational study.

OBJECTIVES

To elucidate predictive clinical factors associated with irreversible complete motor paralysis following traumatic cervical spinal cord injury (CSCI).

SETTING

Hokkaido Spinal Cord Injury Center, Japan.

METHODS

A consecutive series of 447 traumatic CSCI persons were eligible for this study. Individuals with complete motor paralysis at admission were selected and divided into two groups according to the motor functional outcomes at discharge. Initial findings in magnetic resonance imaging (MRI) and other clinical factors that could affect functional outcomes were compared between two groups of participants: those with and those without motor recovery below the level of injury at the time of discharge.

RESULTS

Of the 73 consecutive participants with total motor paralysis at initial examination, 28 showed some recovery of motor function, whereas 45 remained complete motor paralysis at discharge, respectively. Multivariate logistic regression analysis showed that the presence of intramedullary hemorrhage manifested as a confined low intensity changes in diffuse high-intensity area and more than 50% of cord compression on MRI were significant predictors of irreversible complete motor paralysis (odds ratio [OR]: 8.4; 95% confidence interval [CI]: 1.2-58.2 and OR: 14.4; 95% CI: 2.5-82.8, respectively).

CONCLUSION

The presence of intramedullary hemorrhage and/or severe cord compression on initial MRI were closely associated with irreversible paralysis in persons with motor complete paralysis following CSCI. Conversely, subjects with a negligible potential for recovery could be identified by referring to these negative findings.

Window of opportunity for surgical decompression in patients with acute traumatic cervical spinal cord injury

OBJECTIVE

The objective of this prospective study was to determine the optimal timing for surgical decompression (SD) in patients with acute traumatic cervical spinal cord injury (tSCI) within the first 24 hours of injury.

METHODS

In successive patients with fracture and/or dislocation of the subaxial cervical spine and American Spinal Injury Association Impairment Scale (AIS) grades A-C, receiver operating characteristic curve analysis was used to determine the optimal timing for SD within the first 24 hours of cervical tSCI to obtain a neurological recovery of at least two AIS grades. Multivariate logistic regression was used to model significant neurological recovery with time to SD, degree of spinal canal compromise (SCC), and severity of injury.

RESULTS

In this cohort of 64 patients, the optimal timing for SD to obtain a significant neurological improvement was within 4 hours of injury (95% confidence interval 4-9 hours). Increasing the delay from injury to SD or the degree of SCC significantly reduced the likelihood of significant neurological improvement. Due to the strong correlation with SCC, the severity of injury was a marginally significant predictor of neurological recovery.

CONCLUSIONS

These findings indicate that in patients with acute cervical tSCI and AIS grades A-C, the optimal timing for SD is within the first 4-9 hours of injury, depending on the degree of SCC and the severity of injury. Further studies are required to better understand the interrelationships among the timing of SD, injury severity, and degree of SCC in these patients.

Complete Traumatic Spinal Cord Injury: Current Insights Regarding Timing of Surgery and Level of Injury

STUDY DESIGN

A narrative literature review.

OBJECTIVES

To review the neurological recovery patterns in traumatic spinal cord injury (tSCI) patients with a complete lack of motor and sensory function below the level of injury (ie, ASIA A [American Spinal Injury Association scale]), as well as the impact of level of injury and timing of surgical intervention.

RESULTS

Spontaneous neurological recovery in patients with complete tSCI differs per level of injury: patients with cervical and thoracolumbar tSCI recover ≥1 ASIA grade in 17.3% to 34.0% 1 year after injury, compared with 10.7% to 18.6% in thoracic tSCI. Surgical decompression within 24 hours has a beneficial effect on neurological recovery in patients with complete cervical tSCI, whereas this effect is less clear for thoracic and thoracolumbar tSCI. A 1- or 2-grade improvement in the ASIA scale does not necessarily result in functional recovery.

CONCLUSION

In complete tSCI, the level of injury as well as surgical timing affect neurological recovery. There appears to be a beneficial effect of early surgical decompression in patients with complete cervical tSCI, more so than for thoracic and thoracolumbar tSCI. Frequently, the effect of surgical intervention is evaluated by an improvement in ASIA grade, but it is unclear whether this scale is sensitive enough to evaluate meaningful effectiveness of the intervention and desired outcome for patients with tSCI.

When This Happens, You Want the Best Care: Players' Experiences of Barriers and Facilitators of the Immediate Management of Rugby-Related Acute Spinal Cord Injury

Most contact sports, including rugby union, carry a risk of injury. Although acute spinal cord injuries (ASCIs) in rugby are rare, the consequences of such injuries are far-reaching. Optimal management of these injuries is challenging, and a detailed understanding of the different barriers and facilitators to optimal care is needed. In this study, we aimed to describe the perception of players, regarding factors related to the optimal immediate management of a catastrophic injury in a developing country with socioeconomic and health care inequities. The most frequently reported barriers were transportation delays after injury and admission to appropriate medical facilities. Other barriers included inadequate equipment, the quality of first aid care, and barriers within the acute hospital setting. Barriers were more prevalent in rural and lower socioeconomic areas. These findings are relevant for all rugby stakeholders and may help shape education, awareness, and future policy around the immediate management of ASCIs.

Fluoroscopy-assisted posterior percutaneous reduction for the management of unilateral cervical facet dislocations after unsuccessful closed reduction: A case report

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Open reduction of cervical facet dislocation is needed when closed reduction fails.

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Anterior cervical discectomy and fusion after posterior percutaneous reduction was performed.

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Posterior percutaneous reduction can be useful for cervical facet dislocations.

Introduction

In some cases of cervical facet dislocations, open reduction becomes imperative when closed reduction fails. In these cases, posterior open reduction with subsequent posterior fixation has been favored in previous reports as reduction using the posterior approach is less challenging than that using the anterior approach. However, it invades the posterior cervical muscles, is associated with a high risk of postoperative axial neck pain, and is less likely to restore cervical lordosis than anterior surgery. In this report, we describe a novel reduction technique, posterior percutaneous reduction, which can address this dilemma.

Presentation of case

An attempt to perform closed reduction in a 19-year-old adolescent with a unilateral facet dislocation at the C4-C5 level was unsuccessful. To preserve the posterior cervical muscles and obtain good cervical alignment, we opted for posterior percutaneous reduction and subsequent anterior cervical discectomy and fusion instead of posterior open reduction and fixation. An elevator was inserted into the locked facet percutaneously with fluoroscopic assistance, and reduction was achieved by lever action. Seven days after the percutaneous reduction, anterior cervical discectomy and iliac bone grafting with plate fixation were performed. There were no complications or neurological deficits postoperatively.

Discussion

This report describes the case of a patient who underwent anterior cervical discectomy and fusion after posterior percutaneous reduction with preservation of the posterior cervical muscles for unilateral facet dislocation when closed reduction was unsuccessful.

conclusion

Posterior percutaneous reduction could be a useful option for the management of cervical facet dislocations.

Neurological recovery following traumatic spinal cord injury: a systematic review and meta-analysis

OBJECTIVE

Predicting neurological recovery following traumatic spinal cord injury (TSCI) is a complex task considering the heterogeneous nature of injury and the inconsistency of individual studies. This study aims to summarize the current evidence on neurological recovery following TSCI by use of a meta-analytical approach, and to identify injury, treatment, and study variables with prognostic significance.

METHODS

A literature search in MEDLINE and EMBASE was performed, and studies reporting follow-up changes in American Spinal Injury Association (ASIA) Impairment Scale (AIS) or Frankel or ASIA motor score (AMS) scales were included in the meta-analysis. The proportion of patients with at least 1 grade of AIS/Frankel improvement, and point changes in AMS were calculated using random pooled effect analysis. The potential effect of severity, level and mechanism of injury, type of treatment, time and country of study, and follow-up duration were evaluated using meta-regression analysis.

RESULTS

A total of 114 studies were included, reporting AIS/Frankel changes in 19,913 patients and AMS changes in 6920 patients. Overall, the quality of evidence was poor. The AIS/Frankel conversion rate was 19.3% (95% CI 16.2-22.6) for patients with grade A, 73.8% (95% CI 69.0-78.4) for those with grade B, 87.3% (95% CI 77.9-94.8) for those with grade C, and 46.5% (95% CI 38.2-54.9) for those with grade D. Neurological recovery was significantly different between all grades of SCI severity in the following order: C > B > D > A. Level of injury was a significant predictor of recovery; recovery rates followed this pattern: lumbar > cervical and thoracolumbar > thoracic. Thoracic SCI and penetrating SCI were significantly more likely to result in complete injury. Penetrating TSCI had a significantly lower recovery rate compared to blunt injury (OR 0.76, 95% CI 0.62-0.92; p = 0.006). Recovery rate was positively correlated with longer follow-up duration (p = 0.001). Studies with follow-up durations of approximately 6 months or less reported significantly lower recovery rates for incomplete SCI compared to studies with long-term (3-5 years) follow-ups.

CONCLUSIONS

The authors' meta-analysis provides an overall quantitative description of neurological outcomes associated with TSCI. Moreover, they demonstrated how neurological recovery after TSCI is significantly dependent on injury factors (i.e., severity, level, and mechanism of injury), but is not associated with type of treatment or country of origin. Based on these results, a minimum follow-up of 12 months is recommended for TSCI studies that include patients with neurologically incomplete injury.

Ultra-Early (<12 Hours) Surgery Correlates With Higher Rate of American Spinal Injury Association Impairment Scale Conversion After Cervical Spinal Cord Injury

BACKGROUND

Cervical spinal cord injury (SCI) is a devastating condition with very few treatment options. It remains unclear if early surgery correlated with conversion of American Spinal Injury Association Impairment Scale (AIS) grade A injuries to higher grades.

OBJECTIVE

To determine the optimal time to surgery after cervical SCI through retrospective analysis.

METHODS

We collected data from 48 patients with cervical SCI. Based on the time from Emergency Department (ED) presentation to surgical decompression, we grouped patients into ultra-early (decompression within 12 h of presentation), early (within 12-24 h), and late groups (&gt;24 h). We compared the improvement in AIS grade from admission to discharge, controlling for confounding factors such as AIS grade on admission, injury severity, and age. The mean time from injury to ED for this group of patients was 17 min.

RESULTS

Patients who received surgery within 12 h after presentation had a relative improvement in AIS grade from admission to discharge: the ultra-early group improved on average 1.3. AIS grades compared to 0.5 in the early group (P = .02). In addition, 88.8% of patients with an AIS grade A converted to a higher grade (AIS B or better) in the ultra-early group, compared to 38.4% in the early and late groups (P = .054).

CONCLUSION

These data suggest that surgical decompression after SCI that takes place within 12 h may lead to a relative improved neurological recovery compared to surgery that takes place after 12 h.

Rapid incremental closed traction reduction of cervical facet fracture dislocation: the Stoke Mandeville experience

Study design

Retrospective case series study.

Objective

To determine the success rate and neurological outcomes of rapid incremental closed traction reduction (RICTR) of cervical dislocations with spinal cord compression in the National Spinal Injuries Centre (NSIC), between June 2006 and December 2011.

Setting

Tertiary spinal injuries centre, Stoke Mandeville Hospital, UK.

Methods

A list of cervical trauma patients who were admitted to NSIC between January 2006 and December 2011 was retrieved from the hospital's electronic records, consultant and admission logbooks. Patients, admitted within 7 days of cervical facet dislocation and spinal cord injury (SCI), were included. Retrospective data collection and analysis was done using a data collection form and an Excel spreadsheet.

Results

Seventeen patients have met the eligibility criteria of the study. One patient was excluded because he only had nerve root symptoms. The procedure was successful in 44% of the cases. Eighty-six percent of patients in the successful RICTR group improved in their discharge motor index score (MIS), whereas 43% improved in their post-reduction MIS. Overall, 81% of the cohort had improvements in their discharge MIS.

Conclusion

Our RICTR success rate was low compared to the reported average success rate in the literature, likely due to delays in admission. Neurological outcomes were favourable in the majority of patients at discharge. In our opinion, early admission and RICTR attempts could have improved the results and therefore we would recommend that RICTR procedures are done for suitable patients in the Emergency Departments of Major Trauma Centres (MTC).

Mapping the continuum of care to surgery following traumatic spinal cord injury

BACKGROUND

Traumatic spinal cord injury (SCI) is a devastating injury, frequently resulting in paralysis and a lifetime of medical and social problems. Reducing time to surgery may improve patient outcomes. A vital first step to reduce times is to map current pathways of care from injury to surgery, identify rapid care pathways and factors associated with rapid care pathway times.

METHODS

A retrospective review of the Alfred Trauma Service records was undertaken for all cases of spinal injury recorded in the Alfred Trauma Registry over a three year period. Patients with an Abbreviated Injury Scale (AIS) code matching 148 codes for spinal injury were included in the study. Information extracted from the Alfred Trauma Registry included demographic, clinical and key care timelines.

RESULTS

Of the 342 cases identified, 119 had SCI. The average age of SCI patients was 52 years, with 84% male. The vast majority of SCI patients experienced multiple concurrent injuries (87%). Median time from injury to surgery was 17 h r 28 min for SCI patients in comparison to 28 h r 23 min for non-SCI patients. Three pathways to surgery were identified following Trauma Centre presentation- transfer to surgery direct from trauma unit (median time to surgery was 4 h 17 min.), via Intensive Care (median time to surgery was 24 h 33 min) and via the ward (median time to surgery 28 h r 35 min.) SCI was independently associated with the fastest pathway - direct transfer from trauma unit to surgery - with 41% of SCI cases transferred directly to surgery from the trauma unit.

CONCLUSION

Notwithstanding that the vast majority of SCI patients presented with other traumatic injuries, half of all SCI cases reached surgery within 18 h of injury, with 25% within 9 h. SCI was independently associated with direct transfer to surgery from the trauma unit. SCI patients achieve rapid times to surgery within a complex trauma service. Furthermore, the trauma system is well positioned to implement further time reductions to surgery for SCI patients.

"Recognize and Remove": A Universal Principle for the Management of Sports Injuries

OBJECTIVE

To identify the locations and types of injury that result in players not being immediately removed from the field of play when injured and to quantify the magnitude of the situation.

DESIGN

Prospective cohort epidemiological study with definitions and procedures compliant with the international consensus statement for studies in rugby.

SETTING

Sevens World Series (SWS) (2008-2016) and Rugby World Cup (RWC) (2007, 2011, 2015).

PARTICIPANTS

Players from 17 countries taking part in the SWS and 22 countries taking part in the RWC.

MAIN OUTCOME MEASURES

Location, type, and mean severity of injury, period of match when the injury occurred and whether players were removed from the field of play when injured.

RESULTS

Injured players (51.5%) in the SWS and 33.1% of injured players in the RWC were immediately removed from the field of play at the time of injury. The percentages of players immediately removed varied from 16.7% for hand fractures (severity: 71 days) to 96.7% for shoulder dislocations/subluxations (severity: 105 days) during the SWS and from 4.5% for shoulder ligament sprains (severity: 25 days) to 65.9% for concussions (severity: 9 days) during the RWC. The percentage of players immediately removed from play when injured was not related to the severity of the injury sustained.

CONCLUSIONS

A high proportion of players continue to play (in the same game) after sustaining an injury although the likelihood of being removed from play is not dependent on injury severity.

Neurologic Status on Presentation as Predictive Measurement in Success of Closed Reduction in Traumatic Cervical Facet Fractures

BACKGROUND

Dislocations to cervical facets resulting from traumatic injury often lead to neurologic impairment and can be treated both surgically and in a closed manner.

OBJECTIVE

We sought to evaluate the utilization of closed reduction in the initial management of bilateral facet dislocations over the past 10 years at our institution.

METHODS

We retrospectively reviewed the charts of patients who experienced subaxial cervical facet injury within the Penn Health System between 1 June 2006 and 1 June 2016 to identify patients with bilateral jumped/perched facets. The neurologic injury was identified on the basis of the American Spinal Injury Association (ASIA) spinal cord injury score. Analysis of variance and 2-sample t-tests were used to compare continuous distributions, and chi-square tests were used to compare categorical distributions.

RESULTS

We focused our analyses on patients who presented with bilateral jumped/perched facets with (ASIA A and B) or without (ASIA C, D, E) complete voluntary motor deficit and underwent attempted closed reduction. We found that the rate of successful closed reduction was significantly higher in incomplete motor deficits (5/5, P = 0.04, chi-square test) as compared with complete motor deficits (n = 2/11).

CONCLUSION

Our results demonstrate a significant difference in the success rate of closed reduction in patients with good neurologic status on presentation (ASIA A or B), compared with those with poor neurologic status (ASIA C, D, and E). These results suggest that closed reduction should be attempted in patients with good motor examinations on presentation, whereas those with significant deficits may benefit from earlier surgical intervention.

Traumatic subaxial cervical facet subluxation and dislocation: epidemiology, radiographic analyses, and risk factors for spinal cord injury

BACKGROUND CONTEXT

Distractive flexion injuries (DFIs) of the subaxial cervical spine are major contributors to spinal cord injury (SCI). Prompt assessment and early intervention of DFIs associated with SCI are crucial to optimize patient outcome; however, neurologic examination of patients with subaxial cervical injury is often difficult, as patients commonly present with reduced levels of consciousness. Therefore, it is important to establish potential associations between injury epidemiology and radiographic features, and neurologic involvement.

PURPOSE

The aims of this study were to describe the epidemiology and radiographic features of DFIs presenting to a major Australian tertiary hospital and to identify those factors predictive of SCI. The agreement and repeatability of radiographic measures of DFI severity were also investigated.

STUDY DESIGN/SETTING

This is a combined retrospective case-control and reliability-agreement study.

PATIENT SAMPLE

Two hundred twenty-six patients (median age 40 years [interquartile range = 34]; 72.1% male) who presented with a DFI of the subaxial cervical spine between 2003 and 2013 were reviewed.

OUTCOME MEASURES

The epidemiology and radiographic features of DFI, and risk factors for SCI were identified. Inter- and intraobserver agreement of radiographic measurements was evaluated.

METHODS

Medical records, radiographs, and computed tomography and magnetic resonance imaging scans were examined, and the presence of SCI was evaluated. Radiographic images were analyzed by two consultant spinal surgeons, and the degree of vertebral translation, facet apposition, spinal canal occlusion, and spinal cord compression were documented. Multivariable logistic regression models identified epidemiology and radiographic features predictive of SCI. Intraclass correlation coefficients (ICCs) examined inter- and intraobserver agreement of radiographic measurements.

RESULTS

The majority of patients (56.2%) sustained a unilateral (51.2%) or a bilateral facet (48.8%) dislocation. The C6-C7 vertebral level was most commonly involved (38.5%). Younger adults were over-represented among motor-vehicle accidents, whereas falls contributed to a majority of DFIs sustained by older adults. Greater vertebral translation, together with lower facet apposition, distinguished facet dislocation from subluxation. Dislocation, bilateral facet injury, reduced Glasgow Coma Scale, spinal canal occlusion, and spinal cord compression were predictive of neurologic deficit. Radiographic measurements demonstrated at least a "moderate" agreement (ICC>0.4), with most demonstrating an "almost perfect" reproducibility.

CONCLUSIONS

This large-scale cohort investigation of DFIs in the cervical spine describes radiographic features that distinguish facet dislocation from subluxation, and associates highly reproducible anatomical and clinical indices to the occurrence of concomitant SCI.

Acute Thoracolumbar Spinal Cord Injury: Relationship of Cord Compression to Neurological Outcome

BACKGROUND

Spinal cord injury in the cervical spine is commonly accompanied by cord compression and urgent surgical decompression may improve neurological recovery. However, the extent of spinal cord compression and its relationship to neurological recovery following traumatic thoracolumbar spinal cord injury is unclear. The purpose of this study was to quantify maximum cord compression following thoracolumbar spinal cord injury and to assess the relationship among cord compression, cord swelling, and eventual clinical outcome.

METHODS

The medical records of patients who were 15 to 70 years of age, were admitted with a traumatic thoracolumbar spinal cord injury (T1 to L1), and underwent a spinal surgical procedure were examined. Patients with penetrating injuries and multitrauma were excluded. Maximal osseous canal compromise and maximal spinal cord compression were measured on preoperative mid-sagittal computed tomography (CT) scans and T2-weighted magnetic resonance imaging (MRI) by observers blinded to patient outcome. The American Spinal Injury Association (ASIA) Impairment Scale (AIS) grades from acute hospital admission (≤24 hours of injury) and rehabilitation discharge were used to measure clinical outcome. Relationships among spinal cord compression, canal compromise, and initial and final AIS grades were assessed via univariate and multivariate analyses.

RESULTS

Fifty-three patients with thoracolumbar spinal cord injury were included in this study. The overall mean maximal spinal cord compression (and standard deviation) was 40% ± 21%. There was a significant relationship between median spinal cord compression and final AIS grade, with grade-A patients (complete injury) exhibiting greater compression than grade-C and D patients (incomplete injury) (p < 0.05). Multivariate logistic regression identified mean spinal cord compression as independently influencing the likelihood of complete spinal cord injury (p < 0.01).

CONCLUSIONS

Traumatic thoracolumbar spinal cord injury is commonly accompanied by substantial cord compression. Greater cord compression is associated with an increased likelihood of severe neurological deficits (complete injury) following thoracolumbar spinal cord injury.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Clinical outcomes of late decompression surgery following cervical spinal cord injury with pre-existing cord compression

STUDY DESIGN

Retrospective cohort study.

OBJECTIVES

The purpose of the current study was to examine the effectiveness of late decompression surgery for traumatic cervical spinal cord injury (CSCI) with pre-existing cord compression.

SETTING

Murayama Medical Center, National Hospital Organization, Tokyo, Japan.

METHODS

In total 78 patients with traumatic CSCI without bone injury hospitalized in 2012-2015 in our institute for rehabilitation after initial emergency care were divided into four groups according to the compression rate (CR) of the injured level and whether or not decompression surgery was performed. Neurological status was evaluated by American Spinal Injury Association impairment scale (AIS), Barthel index, and Spinal Cord Independence Measure (SCIM).

RESULTS

In the severe compression group (CR ≥ 40%), >2 grade improvement in the AIS was observed in 30% of patients with surgical treatment, although it was not observed in any patient without surgery. The SCIM improvement rate at discharge was 60% in the surgical treatment group and 20% in the non-surgical treatment group. In the minor compression group (CR < 40%), >2 grade improvement in the AIS was observed in 18% of patients with surgical treatment and in 11% without surgery. The SCIM improvement rate at discharge was 52% in the surgical treatment group and 43% in the non-surgical treatment group.

CONCLUSIONS

These results indicate that surgical treatment has an advantage for patients following traumatic CSCI with severe cord compression. In contrast, surgical efficacy is not proved for CSCI patients without severe cord compression.

Effect of spinal cord compression on local vascular blood flow and perfusion capacity by Alshareef M, Krishna V, Ferdous J, Aishareef A, Kindy M, Kolachalama VB, et al

BACKGROUND

Different degrees of blood flow/vascular compromise occur with anterior, posterior, or circumferential spinal cord compression/spinal cord injury (SCI). SCI is also divided into primary and secondary injury. Primary SCI refers to the original neurological damage to tissues, whereas secondary injury reflects interruption of normal blood flow leading to further inflammatory response/other local changes which contribute to additional neurological injury.

METHODS

The authors developed a quantitative "3-D finite element fluid structure interaction model" of spinal cord blood flow to better document the mechanisms of secondary ischemic damage occurring in the spinal cord anteriorly, posteriorly, or circumferentially. This included assessment of the anterior spinal artery (ASA) and five arterial branches (L1, L2, L3, R1, R2), but excluded the microvasculature.

RESULTS

Different locations of cord compression resulted in alternative patterns of spinal cord ischemia. Anterior spinal artery (ASA) flow was substantially reduced by direct anterior compression, but resulted in the least vascular compromise. Alternatively, posterior compression resulted in a significant and critical reduction of distal ASA blood flow and, therefore, correlated with the greatest susceptibility to acute ischemia. Counterintuitively, they concluded "at equivalent degrees of dural occlusion, the loss of branch blood flow under anterior posterior compression was intermediate to predictions for purely posterior or anterior loading."

CONCLUSION

Utilizing a computational three-dimensional model, Alshareef et al. observed that anterior cervical cord compression resulted in the least severe compromise of ASA blood flow to the spinal cord, whereas posterior cord compression/SCI maximally reduced distal ASA blood flow potentiating acute ischemia. Therefore, the latter warranted the earliest surgical intervention.

Timing of Surgery in Spinal Cord Injury

STUDY DESIGN

A systematic review of the literature for clinical and preclinical evidence related to timing of decompression following spinal cord injury (SCI).

OBJECTIVE

A review of the literature in search of consensus on what constitutes the ideal time frame for surgical management of SCI.

SUMMARY OF BACKGROUND DATA

Optimal timing for surgical management of SCI remains poorly defined. Despite multiple preclinical and clinical studies, there is still lack of consensus on the optimal time for surgery in SCI.

METHODS

We systematically reviewed the literature for clinical and preclinical evidence related to timing of decompression following SCI. For clinical studies, our review included papers published in English after January 1, 1990. For preclinical studies, we limited our review to papers published after January 2001. The OVID-Medline and Web of Science databases were reviewed for preclinical studies, and the OVID-Medline, Cochrane, and Embase databases were reviewed for clinical studies.

RESULTS

A total of 8792 preclinical articles were identified. Of those, only 14 met our inclusion criteria and were included in the analysis. A total of 25,190 clinical articles were identified. Of those, only 30 studies met our inclusion criteria and were included for analysis. Clinical studies reported on a total of 5236 patients, of whom 1665 underwent early decompression and 3571 underwent late decompression. There was significant variability in the definition of early and late decompression in both clinical and preclinical studies. Preclinical data were in favor of early decompression. From a clinical standpoint, there was only level II evidence proving safety and feasibility of early decompression with no definite evidence of improved outcome for any of the two groups.

CONCLUSION

There is growing evidence in favor of early decompression following SCI. Early decompression was proven to be clinically safe and feasible, but there is still no definite proof that early decompression leads to improved outcomes.

LEVEL OF EVIDENCE

5.

Neurological Recovery after Traumatic Cervical Spinal Cord Injury Is Superior if Surgical Decompression and Instrumented Fusion Are Performed within 8 Hours versus 8 to 24 Hours after Injury: A Single Center Experience

A prospective study was performed to evaluate the impact of surgical decompression (SD) and instrumented fusion within 8 h versus 8-24 h after injury on neurological recovery after cervical traumatic spinal cord injury (tSCI) in patients operated on in the UMC Ljubljana, Slovenia. Only patients with the American Spinal Injury Association (ASIA) Impairment Scale (AIS) grades of A through C and with MRI-confirmed spinal cord compression were enrolled. The primary outcome was the change in AIS grade at the 6-month follow-up. Of the 48 enrolled patients, 22 patients who underwent surgery within 8 h (group 8 h) and 20 patients who underwent surgery between 8 and 24 h (Group 8-24 h) after injury concluded the study. At admission, there was no statistically significant difference in AIS grade between the study groups. At the 6-month follow-up, an improvement of at least two AIS grades was found in 45.5% of patients in group 8 h and in 10% of patients in group 8-24 h (p=0.017). The median improvement in the ASIA motor score was 38.5 (10.0-61.0) motor points in group 8 h and 15.0 (8.8-34.0) motor points in group 8-24 h (p=0.0468). In a multivariate analysis, adjusted for the preoperative AIS grade and the degree of spinal canal compromise, the odds of an at least two-grade AIS improvement were at least 106% higher for patients in group 8 h than for patients in group 8-24 h (odds ratio=11.08, p=0.004). No statistically significant difference was found in the rate of perioperative complications, pneumonia, and the number of ventilator-dependent days or the mortality between the groups. Our results suggest that the patients with tSCI who undergo SD within 8 h after injury have superior neurological outcomes than patients who undergo SD 8-24 h after injury, without any increase in the rate of adverse effects.

Effect of spinal cord compression on local vascular blood flow and perfusion capacity

Spinal cord injury (SCI) can induce prolonged spinal cord compression that may result in a reduction of local tissue perfusion, progressive ischemia, and potentially irreversible tissue necrosis. Due to the combination of risk factors and the varied presentation of symptoms, the appropriate method and time course for clinical intervention following SCI are not always evident. In this study, a three-dimensional finite element fluid-structure interaction model of the cervical spinal cord was developed to examine how traditionally sub-clinical compressive mechanical loads impact spinal arterial blood flow. The spinal cord and surrounding dura mater were modeled as linear elastic, isotropic, and incompressible solids, while blood was modeled as a single-phased, incompressible Newtonian fluid. Simulation results indicate that anterior, posterior, and anteroposterior compressions of the cervical spinal cord have significantly different ischemic potentials, with prediction that the posterior component of loading elevates patient risk due to the concomitant reduction of blood flow in the arterial branches. Conversely, anterior loading compromises flow through the anterior spinal artery but minimally impacts branch flow rates. The findings of this study provide novel insight into how sub-clinical spinal cord compression could give rise to certain disease states, and suggest a need to monitor spinal artery perfusion following even mild compressive loading.

The effects of the timing of spinal surgery after traumatic spinal cord injury: a systematic review and meta-analysis

Abstract The debate over the effects of the timing of surgical spinal decompression after traumatic spinal cord injury (tSCI) has remained unresolved for over a century. The aim of the current study was to perform a systematic review and quality-adjusted meta-analysis of studies evaluating the effects of the timing of spinal surgery after tSCI. Studies were searched for through the MEDLINE(®) database (1966 to August 2012) and a 15-item, tailored scoring system was used for assessing the included studies' susceptibility to bias. Random effects and quality effects meta-analyses were performed. Models were tested for robustness using one way and criterion-based sensitivity analysis and funnel plots. Results are presented as weighted mean differences (WMDs) and odds ratios (ORs) with 95% confidence intervals (CIs). A total of 18 studies were analyzed. Heterogeneity was evident among the studies included. Quality effects models showed that - when compared with "late" surgery - "early" spinal surgery was significantly associated with a higher total motor score improvement (WMD: 5.94 points, 95% CI:0.74,11.15) in seven studies, neurological improvement rate (OR: 2.23, 95% CI:1.35,3.67) in six studies, and shorter length of hospital stay (WMD: -9.98 days, 95% CI:-13.10,-6.85) in six studies. However, one way and criterion-based sensitivity analyses demonstrated a profound lack of robustness among pooled estimates. Funnel plots showed significant proof of publication bias. In conclusion, despite the fact that "early" spinal surgery was significantly associated with improved neurological and length of stay outcomes, the evidence supporting "early" spinal surgery after tSCI lacks robustness as a result of different sources of heterogeneity within and between original studies. Where the conduct of a surgical, randomized controlled trial seems to be an unfeasible undertaking in acute tSCI, methodological safeguards require the utmost attention in future cohort studies. (Prospero registration number: PROSPERO CRD42012003182. See also http://www.crd.york.ac.uk/NIHR_PROSPERO/ ).