The value of computed tomography in thoracolumbar fractures. An analysis of one hundred consecutive cases and a new classification

Comparison of the Clinical and Radiologic Outcomes of Two Treatment Methods in Patients with Thoracolumbar Junction Distraction Fracture: Short- versus Long-Segment Posterior Stabilization

BACKGROUND

 We compare the radiologic and clinical results between the short-segment fixation and the long-segment fixation in the thoracolumbar junction distraction fractures.

METHODS

 We retrospectively reviewed the prospectively recorded data of patients who underwent posterior approach and pedicle fixation treatment for thoracolumbar distraction fracture (Arbeitsgemeinschaft für Osteosynthesefragen/Orthopaedic Trauma Association AO/OTA 5-B) with a minimum of 2 years of follow-up. A total of 31 patients were operated on; they were divided into two groups: (1) patients treated with short-level fixation (SLF; one level above and below the fracture level) and (2) patients treated with long-level fixation (LLF; two levels above and below the fracture level). The clinical outcomes were evaluated with the neurologic status, operation time, and time to surgery. The functional outcomes were evaluated with the Oswestry Disability Index (ODI) questionnaire and visual analog scale (VAS) at the final follow-up. Radiologic outcomes were measured with the local kyphosis angle, anterior body height, posterior body height, and sagittal index of the fractured vertebra.

RESULTS

 SLF was performed in 15 patients and LLF was performed in 16 patients. The average follow-up period was 30.13 ± 11.3 months for the SLF group and 35.3 ± 17.2 months for group 2 (p = 0.329). The two groups were similar in regard to age, gender, follow-up period, fracture level, fracture type, and pre- and postoperative neurologic status. The operating time was significantly shorter in the SLF group than in the LLF group. There were no significant differences between the groups in all radiologic parameters, ODI score, and VAS.

CONCLUSION

 SLF was associated with a shorter operation time and allowed the preservation of two or more segments of vertebral motion.

A Novel Bipedicular Dissociation Fracture Pattern of Vertebral Osteoporotic Fractures of the Elderly

INTRODUCTION

CVFs are common, with several classification systems available. We have encountered osteoporotic vertebral fractures (OVFs) with PDF, a never-described fracture pattern.This study evaluates this unique fracture's characteristics.

METHODS

Retrospective study of surgically treated OVFs during 2016 to 2020.

RESULTS

Of 105 patients, 85 had classifiable OVFs and 20 had uni-PDF (n = 10, 9.5%) or bi-PDF (n = 10, 9.5%). Both cohorts mainly had single vertebral fractures and upper end plate involvement with cleft sign found in 30% of PDFs versus 15.3% of OVFs (P < 0.001), higher incidence of burst fractures (40% vs. 25.9%; P < 0.001). Posterior vertebral body collapse was higher for PDFs (13.2 ± 9.3% vs. 18.3 ± 8.5%; P = 0.02). Most OVFs underwent balloon kyphoplasty (BKP) (94%). Most bi-PDFs were regarded unstable; six patients underwent PSF (2 short PSF, 1 PSF + BKP, and 3 BKP with intravertebral pedicular lag screws at the fractured vertebra). Half of the bi-PDFs underwent BKP-developed nonunion.

CONCLUSION

Our study is novel in describing an unrecognized OVF pattern disregarded in current classification systems. We found notable differences in fracture characteristics, prefracture functional status, and surgical results between OVF and PDF cohorts. We suggest adding this fracture pattern as a unique OF-4 subtype or a specific entity between OF-4 and 5, with uni-PDF as type A and bi-PDF as type B.

The AO Spine Thoracolumbar Injury Classification System and Treatment Algorithm in Decision Making for Thoracolumbar Burst Fractures Without Neurologic Deficit

STUDY DESIGN

Prospective Observational Study.

OBJECTIVE

To determine the alignment of the AO Spine Thoracolumbar Injury Classification system and treatment algorithm with contemporary surgical decision making.

METHODS

183 cases of thoracolumbar burst fractures were reviewed by 22 AO Spine Knowledge Forum Trauma experts. These experienced clinicians classified the fracture morphology, integrity of the posterior ligamentous complex and degree of comminution. Management recommendations were collected.

RESULTS

There was a statistically significant stepwise increase in rates of operative management with escalating category of injury (P < .001). An excellent correlation existed between recommended expert management and the actual treatment of each injury category: A0/A1/A2 (OR 1.09, 95% CI 0.70-1.69, P = .71), A3/4 (OR 1.62, 95% CI 0.98-2.66, P = .58) and B1/B2/C (1.00, 95% CI 0.87-1.14, P = .99). Thoracolumbar A4 fractures were more likely to be surgically stabilized than A3 fractures (68.2% vs 30.9%, P < .001). A modifier indicating indeterminate ligamentous injury increased the rate of operative management when comparing type B and C injuries to type A3/A4 injuries (OR 39.19, 95% CI 20.84-73.69, P < .01 vs OR 27.72, 95% CI 14.68-52.33, P < .01).

CONCLUSIONS

The AO Spine Thoracolumbar Injury Classification system introduces fracture morphology in a rational and hierarchical manner of escalating severity. Thoracolumbar A4 complete burst fractures were more likely to be operatively managed than A3 fractures. Flexion-distraction type B injuries and translational type C injuries were much more likely to have surgery recommended than type A fractures regardless of the M1 modifier. A suspected posterior ligamentous injury increased the likelihood of surgeons favoring surgical stabilization.

Classification of thoracic spine fractures: the four-column theory

PURPOSE

The purpose of this study is to present a classification of thoracic spine fractures based on anatomical and biomechanical characteristics.

METHODS

This is a narrative review of the literature.

RESULTS

The classification is based on the relationship between movement and common forces acting on the spine. A mechanistic concept is incorporated into the classification, which considers both movements and the application of forces, leading to pathomorphological characteristics. A hierarchical ranking determines the severity of fractures within the thoracic spine, and treatment recommendations are presented in each category. The fourth column of the spine is incorporated into the classification through direct and indirect mechanisms.

CONCLUSIONS

The proposed classification accommodates several advantages, such as simplicity and practicality, that make this classification helpful in daily practice. The dynamic relationship between movement and force provides a better understanding of the fracture mechanism. Finally, incorporating the fourth column will strengthen the indication for surgical management. To the best of our knowledge, this classification is the first classification developed uniquely for the thoracic spine fractures and will help to address a critical gap in the literature.

Evaluation of the Thoracolumbar Injury Classification and Severity (TLICS) Score Over a Two-Year Period at a Level One Trauma Center

Introduction The use of the Thoracolumbar Injury Classification and Severity Score (TLICS) and other classification systems for guiding the management of traumatic spinal injuries remains controversial. TLICS is one of the few classifications that provides treatment recommendations.We sought to analyze intervention modality selection based on the TLICS scoring system. Methods A retrospective review of patients presenting with traumatic thoracolumbar fractures at a level 1 trauma center over a two-year period was performed. Primary endpoints for comparison analysis included visual analog scale (VAS) scores and Cobb angles during follow-up. Results There were 272 patients with thoracolumbar fractures, of whom 212 had TLICS of ≤3, six with TLICS of 4, and 54 with TLICS of ≥5. Of the 272 total patients, 59 were treated via surgery and 213 via non-surgical conservative methods. The VAS scores significantly decreased from presentation to last follow-up in both surgically treated and conservative groups (p<0.0001). This remained consistent in subgroup analyses of TLICS ≤ 3, TLICS = 4, and TLICS ≥ 5 (p<0.0001). Burst fractures treated conservatively had larger fracture Cobb angles versus those treated via surgery at the last follow-up, although this was not significantly associated (p=0.07). The only significant relationship with Cobb angles was in distraction fractures of the TLICS > 4 conservative group, who had significantly lower Cobb angles at the last follow-up than the TLICS > 4 surgical group (p<0.04). The "surgeon's choice" for TLICS = 4 was surgical intervention (4/6 patients, 66.7%). Conclusion Using the TLICS score, thoracolumbar injuries in a level 1 trauma center are more commonly TLICS ≤ 3. For patients with TLICS = 4, the surgeon's choice was most commonly surgical repair. VAS scores decreased over time from presentation between surgically and conservatively managed patients (as well as within-group analyses). The data concerning Cobb angles were more ambiguous, as larger Cobb angles in burst fractures treated conservatively did not show statistically significant differences with surgery.

Correlation between presence of traumatic disco-ligamentous injuries as an MRI finding with the results of management of thoracolumbar and lumbar injuries

Introduction: Radiographic study plays an important role in diagnosis of acute vertebral injuries and helps in proper management of those patients. Magnetic resonance imaging (MRI) is the modality of choice for evaluation of ligamentous and other soft tissue structures, disc, spinal cord and occult osseous injuries. Due to high cost, it is necessary to detect the best use of this technique in the evaluation of thoracolumbar spinal injuries. The purpose of this study was to evaluate the importance of MRI as indicators for vertebral ligamentous injuries and intervertebral disc injuries or herniation in management of thoracolumbar and lumbar fractures. Methods: Retrospective study using radiological measurements. Seventy-two patients with thoracolumbar and lumbar fractures were included. Radiographic parameters detected were percentage of compression, kyphosis angle, vertebral translation and scoliosis angle. Computed tomography was used to detect the degree of spinal canal narrowing, MRI was used to evaluate the condition of posterior ligamentous complex and intervertebral disc injury or herniation. American Spinal Injury Association score was recorded. Results: There were 83% AO spine type A, 6% AO spine type B and 11% AO spine type C. Correlation between fracture type and neurological status with the posterior ligamentous complex injury was found to be significant: ( P = 0.0143 and P = 0.0344, respectively). Degree of vertebral body compression, kyphosis and scoliosis angles, vertebral body translation and spinal canal narrowing were found to be insignificant in correlation with posterior ligamentous complex injuries. Correlation of the above-mentioned parameters with disc injury or herniation was found to be insignificant except for kyphotic angle that was found to be significant in correlation with posttraumatic disc herniation ( P = 0.0219). Conclusion: MRI finding is of great value in management plan of thoracolumbar and lumbar fractures. Injury of posterior ligamentous complex is significantly correlated with fracture severity and the neurological function. But the intervertebral disc injury or herniation was not correlated to them except that the disc herniation was significantly correlated to kyphosis angle.

Surgical management of thoracolumbar junction fractures: An evidence-based algorithm

Background

The management of thoracolumbar junction (TLJ) fractures, involving the restoring anatomical stability and biomechanics properties, still remains a challenge for neurosurgeons.Despite the high frequency of these injuries, specific treatment guidelines, set on biomechanical properties, have not yet been assumed. The present study is meant to propose an evidence-based treatment algorithm. The primary aim for the protocol validation was the assessment of postoperative neurological recovery. The secondary objectives concerned the evaluation of residual deformity and rate of hardware failure. Technical nuances of surgical approaches and drawbacks were further discussed.

Methods

Clinical and biomechanical data of patients harboring a single TLJ fracture, surgically managed between 2015 and 2020, were collected. Patients' cohorts were ranked into 4 groups according to Magerl's Type, McCormack Score, Vaccaro PLC point, Canal encroachment, and Farcy Sagittal Index. The outcome measures were the early/late Benzel-Larson Grade and postoperative kyphosis degree to estimate neurological status and residual deformity, respectively.

Results

32 patients were retrieved, 7, 9, 8, and 8 included within group 1, 2, 3, and 4, respectively. Overall neurological outcomes significantly improved for all patients at every follow-up stage (p ​< ​0.0001). Surgeries gained a complete restoration of post-traumatic kyphosis in the entire cohort (p ​< ​0.0001), except for group 4 which experienced a later worsening of residual deformity.

Conclusions

The choice of the most appropriate surgical approach for TLJ fractures is dictated by morphological and biomechanical characteristics of fracture and the grade of neurological involvement. The proposed surgical management protocol was reliable and effective, although further validations are needed.

EVALUATION OF KYPHOSIS MEASUREMENT IN THORACOLUMBAR SPINE FRACTURES

ABSTRACT Objectives: Evaluate the reliability and reproducibility of the kyphosis measurement in thoracolumbar spine traumatic fractures by different assessment methods in different types of fractures. Methods: Fifteen fractures of the thoracolumbar spine, previously classified into types A, B, and C according to Magerl’s classification, were evaluated. The value of kyphosis was measured using five different methods: (1) Cobb angle; (2) Gardner’s method; (3) back wall method; (4) angle of adjacent endplates; and (5) wedge angle. The measurements were performed by five independent observers and repeated five times with a minimum interval of two weeks between each evaluation. Results: Intraobserver reliability was excellent among the five observers, evidencing good reproducibility of the methods. The five methods used also showed great intraobserver reliability in the global analysis, with methods one and four being more consistent. Conclusion: Although there is no universal agreement on measuring kyphosis in thoracolumbar fractures, our study concluded that method 1 (Cobb angle) and method 4 (adjacent endplate angle) presented the best interobserver reliabilities. Furthermore, the use of digitized radiographs and a simple computer program allowed the performance of highly reliable and reproducible measurements by all methods, given the high intraobserver reliability. Level of Evidence II; Comparative study.

Analysis of a Hybrid Spine Fixation Approach for the Treatment of Unstable Thoracolumbar Fractures

Introduction The treatment of unstable thoracolumbar burst fractures and fracture dislocations of the thoracolumbar spine remains ever evolving. Anterior or posterior approaches both have equal efficacy, but the posterior approach has been preferred in our study due to its ease of application, less extensile nature, and reduced intra-operative bleeding. Posterior approaches can employ short-segment fixation or long-segment fixation techniques. Long segment fixation may need implant removal later to increase mobility in nonfusion surgeries. The thoracolumbar segment is a transition zone where the thoracic spine is a less flexible zone, and the lumbar spine is a more flexible zone. Lumbar motion is important to preserve. Hence, we proposed to study spinal fixation two levels above and one level below the fracture for stabilization. This may provide increased stability along with preservation of the motion segment at the lumbar level. Methods We retro-prospectively reviewed the results of unstable thoracolumbar junction fractures with incomplete or intact neurology in 34 consecutive cases operated with alternate two above and one below fixation approach between June 2018 and June 2019 at our institute. Five cases were excluded due to incomplete follow up and the remaining 29 patients were included in the study. Regular follow-up in the postoperative period at three, six, and 12 months was conducted. Data analysis was done by SPSS software version 22 (IBM Corp., Armonk, NY). Results Twenty-nine patients were included in the study out of which 16 were males and 13 were females. The average age was 36.31±1.46 years (range, 14-60 years). The average follow-up duration was 14.31 months. The average injury to surgery interval was 7.17±7.31 days (range, 1-30 days). On analysis via paired t-test, pre-operative kyphotic angle (mean=20.06±8.34º) improved to immediate post-operative (mean=8.44±5.76º, p=0.0001). The postoperative kyphotic angle at 12 months follow-up showed significant stability (Mean=14.13±5.27º, p=0.0001). A median average pre-operative neurological compromise was ASIA score C and Frankel Grade C and the median average disability was an ODI score of 61%-80%. At the end of 12 months of follow-up the median average neurological compromise improved to ASIA Score D and Frankel Grade D and the median average disability improved to an ODI score of 21%-40%. Conclusion Two levels above and one level below hybrid pedicle screw fixation with decompression for the treatment of unstable thoracolumbar fractures with partial and intact neurology was successful within the limited time frame we had for follow-up in preserving progressive post-operative kyphosis, preserving one-motion segment, improving the neurological outcome and disability of the patients without any major complications.

Modern Diagnostic Imaging Technique Applications and Risk Factors in the Medical Field: A Review

Medical imaging is the process of visual representation of different tissues and organs of the human body to monitor the normal and abnormal anatomy and physiology of the body. There are many medical imaging techniques used for this purpose such as X-ray, computed tomography (CT), positron emission tomography (PET), magnetic resonance imaging (MRI), single-photon emission computed tomography (SPECT), digital mammography, and diagnostic sonography. These advanced medical imaging techniques have many applications in the diagnosis of myocardial diseases, cancer of different tissues, neurological disorders, congenital heart disease, abdominal illnesses, complex bone fractures, and other serious medical conditions. There are benefits as well as some risks to every imaging technique. There are some steps for minimizing the radiation exposure risks from imaging techniques. Advance medical imaging modalities such as PET/CT hybrid, three-dimensional ultrasound computed tomography (3D USCT), and simultaneous PET/MRI give high resolution, better reliability, and safety to diagnose, treat, and manage complex patient abnormalities. These techniques ensure the production of new accurate imaging tools with improving resolution, sensitivity, and specificity. In the future, with mounting innovations and advancements in technology systems, the medical diagnostic field will become a field of regular measurement of various complex diseases and will provide healthcare solutions.

An updated management algorithm for incorporating minimally invasive techniques to treat thoracolumbar trauma

OBJECTIVE

Minimally invasive surgery (MIS) techniques can effectively stabilize and decompress many thoracolumbar injuries with decreased morbidity and tissue destruction compared with open approaches. Nonetheless, there is limited direction regarding the breadth and limitations of MIS techniques for thoracolumbar injuries. Consequently, the objectives of this study were to 1) identify the range of current practice patterns for thoracolumbar trauma and 2) integrate expert opinion and literature review to develop an updated treatment algorithm.

METHODS

A survey describing 10 clinical cases with a range of thoracolumbar injuries was sent to 12 surgeons with expertise in spine trauma. The survey results were summarized using descriptive statistics, along with the Fleiss kappa statistic of interrater agreement. To develop an updated treatment algorithm, the authors used a modified Delphi technique that incorporated a literature review, the survey results, and iterative feedback from a group of 14 spine trauma experts. The final algorithm represented the consensus opinion of that expert group.

RESULTS

Eleven of 12 surgeons contacted completed the case survey, including 8 (73%) neurosurgeons and 3 (27%) orthopedic surgeons. For the 4 cases involving patients with neurological deficits, nearly all respondents recommended decompression and fusion, and the proportion recommending open surgery ranged from 55% to 100% by case. Recommendations for the remaining cases were heterogeneous. Among the neurologically intact patients, MIS techniques were typically recommended more often than open techniques. The overall interrater agreement in recommendations was 0.23, indicating fair agreement. Considering both literature review and expert opinion, the updated algorithm indicated that MIS techniques could be used to treat most thoracolumbar injuries. Among neurologically intact patients, percutaneous instrumentation without arthrodesis was recommended for those with AO Spine Thoracolumbar Classification System subtype A3/A4 (Thoracolumbar Injury Classification and Severity Score [TLICS] 4) injuries, but MIS posterior arthrodesis was recommended for most patients with AO Spine subtype B2/B3 (TLICS > 4) injuries. Depending on vertebral body integrity, anterolateral corpectomy or mini-open decompression could be used for patients with neurological deficits.

CONCLUSIONS

Spine trauma experts endorsed a range of strategies for treating thoracolumbar injuries but felt that MIS techniques were an option for most patients. The updated treatment algorithm may provide a foundation for surgeons interested in safe approaches for using MIS techniques to treat thoracolumbar trauma.

Computer Simulated Enhancement and Planning, Robotics and Navigation With Patient Specific Implants and 3-D Printed Cages

STUDY DESIGN

This is a retrospective cohort study.

OBJECTIVES

Pre and postop Measurement Testing. This is a retrospective study of 33 consecutive interbody spacers in 21 patients who underwent pre, intra, and postoperative measurement of the middle column to determine if this would lead to more precise restoration of middle column height and spacer fit. Scaled transparencies of the pre-operative simulation of angular correction and spacer geometry could be overlayed on the post-operative imaging studies.

METHODS

Multiple Observers Measurement Testing. 33 consecutive vertebral levels requiring interbody spacers for multilevel deformities had middle column height pre and post operatively measured by 3 blinded observers. The preoperative and postoperative measurements were compared using a linear regression analysis and Pearson product-moment correlation.

RESULTS

Pre and postop Measurement Testing: Thirty-three interbody devices in 21 patients had pre-operative planning, simulation of cage dimensions to determine the proper cage fit which would provide for the desired correction of foraminal height and sagittal balance parameters. The simulated preoperative plan overlayed the final post-operative radiograph and was a near-perfect match in 20 of 21 patients (95.2%). Multiple Observers Measurement Testing: A Pearson product-moment correlation was run between each individual's pre-op and post-op middle column measurements. There was a strong, positive correlation between pre-operative and post-operative measurements, which was statistically significant (r = 0.903, n = 33, P < 0.001).

CONCLUSIONS

This consecutive series of 33 cases demonstrated the utility of measuring the preoperative middle column length in predicting the optimal height of the spacers, intervertebral disks, and posterior vertebral body height simultaneously restoring sagittal and coronal plane alignment.

Predictors of adverse events after percutaneous pedicle screws fixation in patients with single-segment thoracolumbar burst fractures

BACKGROUND

Percutaneous pedicle screw fixation (PPSF) is the primary approach for single-segment thoracolumbar burst fractures (TLBF). The healing angle at the thoracolumbar junction is one of the most significant criteria for evaluating the efficacy of PPSF. Therefore, the purpose of this study was to analyze the predictors associated with the poor postoperative alignment of the thoracolumbar region from routine variables using a support vector machine (SVM) model.

METHODS

We retrospectively analyzed patients with TLBF operated at our academic institute between March 1, 2014 and December 31, 2019. Stepwise logistic regression analysis was performed to assess potential statistical differences between all clinical and radiological variables and the adverse events. Based on multivariate logistic results, a series of independent risk factors were fed into the SVM model. Meanwhile, the feature importance of radiologic outcome for each parameter was explored. The predictive performance of the SVM classifier was evaluated using the area under the receiver operating characteristic curve (AUC), accuracy (ACC) and confusion matrices with 10-fold cross-validation, respectively.

RESULTS

In the recruited 150 TLBFs, unfavorable radiological outcomes were observed in 53 patients (35.33%). The relationship between osteoporosis (p = 0.036), preoperative Cobb angle (p = 0.001), immediate postoperative Cobb angle (p = 0.029), surgically corrected Cobb angle (p = 0.001), intervertebral disc injury (Score 2 p = 0.001, Score 3 p = 0.001), interpedicular distance (IPD) (p = 0.001), vertebral body compression rate (VBCR) (p = 0.010) and adverse events was confirmed by univariate regression. Thereafter, independent risk factors including preoperative Cobb angle, the disc status and IPD and independent protective factors surgical correction angle were identified by multivariable logistic regression. The established SVM classifier demonstrated favorable predictive performance with the best AUC = 0.93, average AUC = 0.88, and average ACC = 0.87. The variables associated with radiological outcomes, in order of correlation strength, were intervertebral disc injury (42%), surgically corrected Cobb angle (25%), preoperative Cobb angle (18%), and IPD (15%). The confusion matrix reveals the classification results of the discriminant analysis.

CONCLUSIONS

Critical radiographic indicators and surgical purposes were confirmed to be associated with an unfavorable radiographic outcome of TLBF. This SVM model demonstrated good predictive ability for endpoints in terms of adverse events in patients after PPSF surgery.

Classification and Radiological Diagnosis of Thoracolumbar Spine Fractures: WFNS Spine Committee Recommendations

The aim of this review to determine recommendations for classification and radiological diagnosis of thoracolumbar spine fractures. Recommendation was made through a literature review of the last 10 years. The statements created by the authors were discussed and voted on during 2 consensus meetings organized by the WFNS (World Federation Neurosurgical Societies) Spine Committee. The literature review was yielded 256 abstracts, of which 32 were chosen for full-text analysis. Thirteen papers evaluated the reliability of a classification system by our expert members and were also chosen in this guideline analysis. This literature review-based recommendation provides the classification and radiologic diagnosis in thoracolumbar spine fractures that can elucidate the management decision-making in clinical practice.

Indications for Nonsurgical Treatment of Thoracolumbar Spine Fractures: WFNS Spine Committee Recommendations

Thoracolumbar spine is the most injured spinal region in blunt trauma. Literature on the indications for nonoperative treatment of thoracolumbar fractures is conflicting. The purpose of this systematic review is to clarify the indications for nonsurgical treatment of thoracolumbar fractures. We conducted a systematic literature search between 2010 to 2020 on PubMed/MEDLINE, and Cochrane Central. Up-to-date literature on the indications for nonoperative treatment of thoracolumbar fractures was reviewed to reach an agreement in a consensus meeting of WFNS (World Federation of Neurosurgical Societies) Spine Committee. The statements were voted and reached a positive or negative consensus using the Delphi method. For all of the questions discussed, the literature search yielded 1,264 studies, from which 54 articles were selected for full-text review. Nine studies (4 trials, and 5 retrospective) evaluating 759 participants with thoracolumbar fractures who underwent nonoperative/surgery were included. Although, compression type and stable burst fractures can be managed conservatively, if there is major vertebral body damage, kyphotic angulation, neurological deficit, spinal canal compromise, surgery may be indicated. AO type B, C fractures are preferably treated surgically. Future research is necessary to tackle the relative paucity of evidence pertaining to patients with thoracolumbar fractures.

Which traumatic spinal injury creates which degree of instability? A systematic quantitative review

BACKGROUND CONTEXT

Traumatic spinal injuries often require surgical fixation. Specific three-dimensional degrees of instability after spinal injury, which represent criteria for optimum treatment concepts, however, are still not well investigated.

PURPOSE

The aim of this review therefore was to summarize and quantify multiplanar instability increases due to spinal injury from experimental studies.

STUDY DESIGN/SETTING

Systematic review.

METHODS

A systematic review of the literature was performed using keyword-based search on PubMed and Web of Science databases in order to detect all in vitro studies investigating the destabilizing effect of simulated and provoked traumatic injury in human spine specimens. Together with the experimental designs, the instability parameters range of motion, neutral zone and translation were extracted from the studies and evaluated regarding type and level of injury.

RESULTS

A total of 59 studies was included in this review, of which 43 studies investigated the effect of cervical spine injury. Range of motion increase, which was reported in 58 studies, was generally lower compared to the neutral zone increase, given in 37 studies, despite of injury type and level. Instability increases were highest in flexion/extension for most injury types, while axial rotation was predominantly affected after cervical unilateral dislocation injury and lateral bending solely after odontoid fracture. Whiplash injuries and wedge fractures were found to increase instability equally in all motion planes.

CONCLUSIONS

Specific traumatic spinal injuries produce characteristic but complex three-dimensional degrees of instability, which depend on the type, level, and morphology of the injury. Future studies should expand research on the cervicothoracic, thoracic, and lumbosacral spine and should additionally investigate the destabilizing effects of the injury morphology as well as concomitant rib cage injuries in case of thoracic spinal injuries. Moreover, neutral zone and translation should be measured in addition to the range of motion, while mechanical injury simulation should be preferred to resection or transection of structures to ensure high comparability with the clinical situation.

Thoracolumbar Spine Trauma

Thoracolumbar spine trauma can result in potentially life-threatening consequences and requires careful management to ensure good outcomes. The purpose of this chapter is to discuss the anatomy, diagnostic tools, non-operative, and operative treatments important when addressing thoracolumbar trauma.

Development and validation of a simplified thoracolumbar spine fracture classification system

STUDY DESIGN

Development and validation of fracture classification system.

OBJECTIVE

To develop and validate a Simplified Classification System (SCS) for Thoraco-Lumbar (TL) fractures (SCS - TL fractures).

SETTING

Tertiary Spinal Injuries Centre, New Delhi, India METHODS: Based on the International Spinal Cord Society Spine Trauma Study Group (ISCoS STSG, n = 23) experts' clinical consensus conducted by the senior author and on his own experience, the Denis classification for TL fractures was modified to develop a SCS-TL fractures that could guide the management. After Face and Content validation, Construct validation was done in two stages. First stage analyzed if management of 30 cases of TL fractures, as suggested by the SCS - TL fractures and ISCoS STSG (n = 9) as well as other (n = 5) experts, matched. Second stage was a one year prospective study analyzing if the management suggested matched the management actually carried out by different spine surgeons (n = 10) working at a single institution.

RESULTS

In the first stage there was 100% agreement for management (conservative or surgical) as proposed by experts and that suggested by the proposed classification for TL fractures whereas for surgical approach there was 88% agreement. In the second stage, there was 100% agreement for the management as well as surgical approach as carried out at our centre and that proposed by the SCS for TL fractures.

CONCLUSIONS

The proposed SCS-TL fractures helps in classifying and in decision making for management of TL fractures. The next phase of validation would involve multicentric reliability studies and prospective application of the SCS- TL fractures.

Review of best classification systems for diagnosing and treating thoracolumbar spine trauma

Background

Improved thoracolumbar spine trauma classification (TLSTC) systems can better help diagnose and treat thoracolumbar spine trauma (TLT). Here, we identified the types of injury (rationale and description), instability criteria, and treatment guidelines of TLSTC.

Methods

We used the PubMed/MEDLINE database to assess TLSTC according to the following variables: injury morphology, injury mechanism, spinal instability criteria, neurological status, and treatment guidelines.

Results

Twenty-one studies, 18 case series and three reviews were included in the study. Treatment guidelines were proposed in 16 studies. The following three major parameters were identified in TLSTC studies: injury morphology (19/21 studies), posterior ligamentous complex (PLC) disruption alone as the main spinal instability criterion (15 studies), and neurological damage (12 studies). Most classification systems neglected the severity of vertebral body comminution.

Conclusion

We identified here the 3 main parameters for the evaluation of diagnosis and treatment of TLT: injury morphology, PLC disruption, and neurological damage. Based on our review, we may conclude that further clinical validation studies of TLSTC are warranted.

Orthosis versus no orthosis for the treatment of thoracolumbar burst fractures: A systematic review

Management of patients with thoracolumbar burst fractures who do not have a neurologic injury has historically been controversial. Whilst management with an orthosis has gained popularity over surgical management, more recent evidence has suggested that even an orthosis may be unnecessary. A systematic review of the literature comparing orthosis with no orthosis in the management of thoracolumbar burst fractures in patients without neurological deficit was conducted. A risk of bias assessment was performed according to the Cochrane Collaboration Back Review Group. The quality of evidence was assessed according to the GRADE system. Two trials met the eligibility criteria. The functional outcomes, radiologic measures of kyphosis, pain scores, and quality of life scores were equivalent between the orthosis and the no orthosis groups. The level of evidence ranged from very low to moderate for the outcomes evaluated. The rate of complications and the rate of failure of treatment requiring surgery was low. Evidence from two small randomised controlled trials suggests that there are equivalent outcomes between treatment with and without an orthosis. Larger trials are needed to assess the treatment effect with greater confidence.

Short-Segment Fixation of Thoracolumbar Fractures with Incorporated Screws at the Level of Fracture

Objective

To evaluate the effect of including the fractured vertebra in the short‐segment fixation of thoracolumbar (TL) fractures.

Methods

A total of 32 patients with thoraco‐lumbar fractures, selected between August 2013 and February 2016, were managed by short‐segment fixation with screws at the level of the fracture, and decompression was performed only for patients with neurological deficits. The patients' functional outcome was assessed using the visual analogue scale (VAS) score for pain and the American Spinal Injury Association (ASIA) score for neurological condition. All patients were followed up with radiographs.

Results

Patients with complete neurologic deficits (n = 3) did not show any neurologic recovery. All ASIA B patients improved to ASIA C. Five ASIA C patients improved to ASIA E. The remaining five ASIA C patients improved to ASIA D. All ASIA D patients improved to ASIA B. At the final follow‐up examination, the mean anterior vertebral height was 21 ± 5 mm, indicating no significant height loss during the follow‐up period.

Conclusion

Short‐segment fixation of TL fractures with inclusion of the fracture level into the construct offers good correction of segmental kyphosis, vertebral wedging, and vertebral height loss.

Clinical Features and Treatment Outcomes of Acute Multiple Thoracic and Lumbar Spinal Fractures : A Comparison of Continuous and Noncontinuous Fractures

Objective

The treatment of multiple thoracolumbar spine fractures according to fracture continuity has rarely been reported. Herein we evaluate the clinical features and outcomes of multiple thoracolumbar fractures depending on continuous or noncontinuous status.

Methods

From January 2010 to January 2016, 48 patients with acute thoracic and lumbar multiple fractures who underwent posterior fusion surgery were evaluated. Patients were divided into two groups (group A : continuous; group B : noncontinuous). We investigated the causes of the injuries, the locations of the injuries, the range of fusion levels, and the functional outcomes based on the patients’ general characteristics.

Results

A total of 48 patients were enrolled (group A : 25 patients; group B : 23 patients). Both groups had similar pre-surgical clinical and radiologic features. The fusion level included three segments (group A : 4; group B : 5) or four segments (group A : 19; group B : 5). Group B required more instrumented segments than did group A. Group A scored 23.5 and group B scored 33.4 on the Korean Oswestry Disability Index (KODI) at the time of last follow-up. In both groups, longer fusion was associated with worse KODI score.

Conclusion

In this study, due to the assumption of similar initial clinical and radiologic features in both group, the mechanism of multiple fractures is presumed to be the same between continuous and noncontinuous fractures. The noncontinuous fracture group had worse KODI scores in long-term follow-up, thought to be due to long fusion level. Therefore, we recommend minimizing the number of segments that are fused in multiple thoracolumbar and lumbar fractures when decompression is not necessary.

Analysis of the disc pressure of the upper thoracic spine using pressure-sensitive film: an experimental study in porcine model-implications for scoliosis progression

There has been few studies focusing on the disc pressure of the upper thoracic spine and it still lacks the quantitative pressure measurement of each spinal disc segment. The aim of this study was to study the pressure changes of intervertebral disc in porcine upper thoracic spine using pressure-sensitive film. Twelve porcine thoracic motion segments were harvested and successively loaded with vertical loads of 100 N, 150 N, and 200 N during 5° of anterior flexion, 5° of posterior extension and 5° of lateral bending. The resulting pressure values were measured. During anterior flexion, the anterior annulus of all segments at all loads showed higher mean pressure values than those during vertical compression, whereas the posterior annulus did not show higher mean values. During posterior extension, the anterior annulus of all segments showed lower mean pressure values than those during vertical compression, whereas the posterior annulus did not show lower mean pressure values. During lateral bending, the annulus of all segments showed higher mean pressure values than those during vertical compression. The posterior thoracic vertebra plays an important role in the motion of the upper thoracic vertebral segment and pressure distribution. During lateral bending, the concave side pressure of the annulus increases obviously, suggesting that asymmetrical force is a contributory factor for scoliosis progression.

The Evaluation of Different Radiological Measurement Parameters of the Degree of Collapse of the Vertebral Body in Vertebral Compression Fractures

For compression fracture, vertebral body height loss (VBHL) and kyphotic angle (KA) are two important imaging parameters for determining the prognosis and appropriate treatment. This study used previous measurement methods to assess the degree of VBHL and KA, compare and examine differences between various measurement methods, and examine the correlation between relevant measurement parameters and intravertebral cleft (IVC) in the vertebral body. The radiographic images (lateral view of the T-L spine) of 18 patients with a single-level vertebral compression fracture were reviewed. We measured 9 characteristic lengths and angles on plain radiographs, including anterior vertebral height (AVH) and AVH of the adjacent upper and lower levels, middle vertebral height (MVH) and MVH of the adjacent upper and lower levels, posterior vertebral height (PVH), and vertebral body width, and assessed 6 parameters, including vertebral compression ratio (VBCR), percentage of anterior height compression (PAHC), percentage of middle height compression (PMHC), kyphotic angle (KA), calculated kyphotic angle (CKA), and IVC. The results showed that VBCR is a simple and rapid method of VBHL assessment, but it may result in an underestimation of the degree of VBHL compared to PAHC. When PMHC < 40% or kyphotic angle > 15°, the probability of IVC occurring on the vertebral body was higher which means the higher risk of vertebral body instability. The results of this study could provide a reference for surgeons when using imaging modalities to assess the degree of vertebral body collapse.

[Modern radiological diagnostics in spine surgery]

BACKGROUND

Radiological imaging is important in the preoperative diagnosis of many forms of spinal pathology and plays a fundamental role in the assessment of p.o. effects, which can be verified on the spinal column as well as on the surrounding soft tissues, depending on the imaging method used.

AIM

The article provides an overview of the current status and possibilities of radiological diagnostic methods for the verification of possibly recommended spine surgery in the context of degenerative, inflammatory-infectious, post-traumatic or p.o. pathologies and changes in the spine: X‑rays, computed tomography (CT), magnetic resonance imaging (MRI). The supplementary nuclear medicine procedures (scintigraphy, PET[-CT], SPECT, etc.) which may be required for special questions are not discussed.

MATERIAL AND METHODS

The merits and limitations of the techniques used in the investigation of advanced degenerative spinal pathologies and post-traumatic conditions are discussed, with multidetector CT being the focus of attention in spinal clearance for traumatic injuries. In most cases of spinal infection, MRI images, as a central diagnostic tool, show typical findings such as destruction of adjacent endplates, bone marrow and intervertebral disc abnormalities, and paravertebral or epidural abscesses. However, it is not always easy to diagnose a spinal infection, especially if atypical MR patterns of infectious spondylitis are present. Knowledge of them means misdiagnosis and improper treatment can be avoided.

RESULTS

It is shown that high-quality modern radiological examinations are essential for diagnosis and p.o. management, as these provide answers to the main questions in the treatment: Is the entity/injury stable or unstable, acute or old, benign or malign; is there a myelopathy or p.o. complication?

DISCUSSION

The main indications for p.o. diagnostic imaging, difficulties such as metal artefact formation, and potential pitfalls are analyzed. Entity-specific radiological image patterns, imaging algorithms and differential diagnostic peculiarities are presented and discussed based on current literature and selected case studies.

Congress of Neurological Surgeons Systematic Review and Evidence-Based Guidelines on the Evaluation and Treatment of Patients With Thoracolumbar Spine Trauma: Classification of Injury

QUESTION 1

Are there classification systems for fractures of the thoracolumbar spine that have been shown to be internally valid and reliable (ie, do these instruments provide consistent information between different care providers)?

RECOMMENDATION 1

A classification scheme that uses readily available clinical data (eg, computed tomography scans with or without magnetic resonance imaging) to convey injury morphology, such as Thoracolumbar Injury Classification and Severity Scale or the AO Spine Thoracolumbar Spine Injury Classification System, should be used to improve characterization of traumatic thoracolumbar injuries and communication among treating physicians. Strength of Recommendation: Grade B.

QUESTION 2

In treating patients with thoracolumbar fractures, does employing a formally tested classification system for treatment decision-making affect clinical outcomes?

RECOMMENDATION 2

There is insufficient evidence to recommend a universal classification system or severity score that will readily guide treatment of all injury types and thereby affect outcomes. Strength of Recommendation: Grade Insufficient The full version of the guideline can be reviewed at: https://www.cns.org/guideline-chapters/congress-neurological-surgeons-systematic-review-evidence-based-guidelines/chapter_2.

Pressure distributions inside intervertebral discs under unilateral pedicle screw fixation in a porcine spine model

Background

Little data are available regarding the effects of pedicle screws on the intervertebral disc stress for different spinal segments. The aim of this study was to analyze the intervertebral disc stress in response to the placement of pedicle screws.

Methods

T3–4, T11–12, T15–L1, L3–4, and L4–5 intervertebral disc segments from six porcine spine specimens were harvested. A compressive load of 200 N was applied both before and after the pedicle screw was implanted on the left side of each target segment; the resulting pressure was measured during vertical, 5° anterior flexion, 5° posterior extension, and 5° lateral bending.

Results

The posterior intradiscal pressures of the intervertebral disc were significantly lower in the fixed group than in the unfixed group for all segments during vertical, 5° anterior flexion, and 5° posterior extension. The left pressures of the intervertebral disc were significantly lower in the fixation group for all segments. During 5° lateral bending, the left intervertebral disc pressures were significantly lower in the fixation group. Lower mean pressures were observed in the fixed group.

Conclusions

Unilateral pedicle screws can effectively reduce the pressure of the fixed lateral intervertebral disc. Moreover, it can change the pressure distribution of the intervertebral disc and reduce the pressure of the entire intervertebral disc, especially the posterior side of the intervertebral disc.

Comparison of sagittal values between lateral decubitus plain radiography and supine computed tomography in thoracolumbar fractures: a greater degree of kyphosis is observed in plain radiography than CT

OBJECTIVE

Radiologic parameters are important factors for planning the treatment for thoracolumbar fracture. However, we noted that measurements of the degree of kyphosis by lateral decubitus plain radiography were greater than supine CT. The cause of this discrepancy is unclear.

METHODS

We retrospectively reviewed the plain radiographs and CT scans of 90 patients with thoracolumbar fractures (fracture group). We measured the segmental sagittal angle (SSA) on lateral decubitus plain radiographs and in the median sagittal plane on CT scans obtained in the supine position. The method agreement (plain radiography versus CT) was determined by utilizing Bland-Altman plots. For the purpose of comparison, the same analyses were performed in a group of age and sex-matched controls (normal group). After establishing the method disagreement in the fracture group, the factors that contributed to the difference in the SSA between plain radiography and CT, as well as their threshold values, were determined.

RESULTS

On Bland-Altman plots for the fracture group, the mean difference was 4.53° [95% confidence interval (CI) - 4.87° to 13.93°]. For the normal group, the mean difference was - 0.64° (95% CI - 5.87° to 4.58°). On univariate analysis, male sex, thoracolumbar level, and SSA(X) were significant factors associated with ∆SSA (P = 0.03, 0.002, and 0.000, respectively). Multivariable regression analysis showed that SSA(X) was the only significant factor. Receiver operating characteristic curve analysis indicated that the optimal threshold of SSA(X) was 17° with a sensitivity of 78% and a specificity of 75% (area under curve: 0.752).

CONCLUSIONS

The mean SSA determined on lateral decubitus plain radiographs indicated significantly more kyphosis than that determined on CT images obtained in supine position. When the SSA on plain radiography is more than 17°, there might be a significant discrepancy between the two imaging modalities. This discrepancy seems to be mainly attributable to the difference in patient positioning (lateral decubitus position for plain radiography versus supine position for CT imaging).

Comparison of Wiltse's paraspinal approach and open book laminectomy for thoracolumbar burst fractures with greenstick lamina fractures: a randomized controlled trial

Background

Posterior short-segment pedicle screw fixation is used to treat thoracolumbar burst fractures. However, no randomized controlled studies have compared the efficacy of the two approaches––the Wiltse’s paraspinal approach and open book laminectomy in the treatment of thoracolumbar burst fractures with greenstick lamina fractures.

Materials and methods

Patients with burst fractures of the thoracolumbar spine without neurological deficit were randomized to receive either the Wiltse’s paraspinal approach (group A, 24 patients) or open book laminectomy (group B, 23 patients). Patients were followed postoperatively for average of 27.4 months. Clinical and radiographic data of the two approaches were collected and compared.

Results

Our results showed the anterior segmental height, kyphotic angle, visual analog scale (VAS) score, and Smiley-Webster Scale (SWS) score significantly improved postoperatively in both groups, indicating that both the Wiltse’s paraspinal approach and open book laminectomy can effectively treat thoracolumbar burst fractures with greenstick lamina fractures. The Wiltse’s paraspinal approach was found to have significantly shorter operating time, less blood loss, and shorter length of hospital stay compared to open book laminectomy. However, there were two (2/24) patients in group A that had neurological deficits postoperatively and required a second exploratory operation. Dural tears and/or cauda equina entrapment were subsequently found in four patients in group B and all two patients of neurological deficits in group A during operation. No screw loosening, plate breakage, or other internal fixation failures were found at final follow-up.

Conclusions

The results demonstrated that either of the two surgical approaches can achieve satisfactory results in treating thoracolumbar burst fractures in patients with greenstick lamina fractures. However, if there is any clinical or radiographic suspicion of a dural tear and/or cauda equina entrapment pre-operation, patients should receive an open book laminectomy to avoid a second exploratory operation. More research is still needed to optimize clinical decision-making regarding surgical approach.

Electronic supplementary material

The online version of this article (10.1186/s13018-018-0743-z) contains supplementary material, which is available to authorized users.

Assessing the utility of the spinal instability neoplastic score (SINS) to predict fracture after conventional radiation therapy (RT) for spinal metastases

PURPOSE

Assessing the stability of spinal metastases is critical for making treatment decisions. The spinal instability neoplastic score (SINS) was developed by the Spine Oncology Study Group to categorize tumor-related lesions; however, data describing its utility in predicting fractures in patients with spinal metastases are limited. The purpose of this study is to assess the validity of SINS in predicting new or worsening fracture after radiation therapy (RT) to spine metastases.

METHODS AND MATERIALS

This is a retrospective analysis of patients treated with conventional RT alone (median total dose, 30 Gy; range, 8-47 Gy; median number of fractions, 10; range, 1-25) for spinal metastasis at Dana-Farber/Brigham and Women's Cancer Center from 2006 to 2013. SINS was calculated for each lesion (range, 0-18). The primary endpoint was time from RT start to radiographically documented new or worsening fracture or last disease assessment.

RESULTS

A total of 203 patients and 250 lesions were included in analysis. The percentages of lesions with SINS of 0 to 6, 7 to 12, and 13 to 18 were 38.8%, 54.8%, and 6.4%, respectively. Of 250 lesions, 20.4% developed new or worsening fractures; 14.4% for SINS 0 to 6, 21.2% for SINS 7 to 12, and 50.0% for SINS 13 to 18. Multivariate analysis adjusted for sex, age, Eastern Cooperative Oncology Group, histology, and total dose indicated that, compared with stable lesions (SINS 0-6), potentially unstable lesions (SINS 7-12) demonstrated a greater likelihood of new or worsening fracture that was not statistically significant (hazard ratio, 1.66; 95% confidence interval, 0.85-3.22; P = .14), and unstable lesions (SINS 13-18) were significantly more likely to develop to new or worsening fracture (hazard ratio, HR,4.37, 95% confidence interval, 1.80-10.61; P = .001).

CONCLUSIONS

In this study of patients undergoing RT for spinal metastases, 20.4% developed new or worsening vertebral fractures. SINS is demonstrated to be a useful tool to assess fracture risk after RT.

[Radiological outcomes of unstable thoraco-lumbar fractures without neurological deficit treated through percutaneous surgery]

OBJECTIVE

To analyse the radiological outcomes in the long term of unstable thoracic and lumbar fractures treated through percutaneous surgery.

MATERIAL AND METHODS

Retrospective review of a series of patients with unstable thoracic and lumbar fractures treated with percutaneous minimally invasive surgery between 2010 and 2015 in three different hospital centres. Six radiological parameters were measured annually during a 2-year period: Fracture angle, kyphotic deformity, sagittal index, percentage of compression, degree of displacement and deformation angle.

RESULTS

A total of 37 patients were included with a median age of 41.3 years and a median follow-up period of 2.2 years. Fracture angle rose from 14.8° to 17.1° (increase of 15.54%), kyphotic deformity from 15.9° to 17.7° (increase of 11.32%), sagittal index from 10.1 to 12.3 (increase of 21.78%), percentage of compression from 32.7% to 36.8% (increase of 12.53%), degree of displacement from 3.0mm to 4.4mm (increase of 50%) and deformation angle from 20.7° to 22.9° (increase of 10.62%).

CONCLUSIONS

All the radiological parameters studied lost correction throughout the 24 months of follow-up; the degree of displacement and the sagittal index were the most marked. Nevertheless, the greatest loss of correction occurred in the first postoperative year, the parameters then stabilised over the 24 months of follow up. We routinely recommend the measurement of all previous parameters for the follow up of unstable thoracic and lumbar fractures treated through percutaneous surgery.

Anterior Lumbar Corpectomy with Expandable Titanium Cage Reconstruction: A Case Series of 42 Patients

BACKGROUND

Burst fractures involve the anterior and middle columns with an intact posterior column. Deforming forces are magnified at areas of transition, making the thoracolumbar junction highly susceptible to injury.

METHODS

This is a retrospective review of 42 consecutive patients who underwent single-level anterior lumbar corpectomy using an obelisc expandable titanium cage and lateral fixation for traumatic lumbar burst fractures.

RESULTS

Myelopathy and sensory dysfunction were the most frequent neurologic deficits initially, occurring in 16 (38%) and 15 (36%) patients, respectively, which both decreased to 5 (13%). At follow-up, 26 patients (68%) were able to ambulate independently. No patient had significant cage displacement or needed cage replacement. Subsidence was minimal in 32 of 39 patients (82%). There were no hardware infections or surgical site infections. Options for stabilization include posterior instrumentation and fusion, anterior corpectomy with interbody fusion, and combination procedures. We believe anterior stabilization is superior because the aim is structural restoration of anterior and middle columns. The aim of posterior fixation is to replace the posterior tension band, which is not affected. There are 3 major surgical components to consider. First is anterior versus posterior decompression of the spinal canal. Second is the choice of autograft or titanium graft. Third is whether to stabilize posteriorly or anterolateral.

CONCLUSIONS

Anterior corpectomy with an expandable titanium cage and lateral rod fixation is safe and effective with minimal complications. It is a viable alternative to posterior decompression and instrumentation.

Stepwise resection of the posterior ligamentous complex for stability of a thoracolumbar compression fracture: An in vitro biomechanical investigation

To quantify the mechanical contribution of posterior ligamentous structures to the stability of thoracolumbar compression fractures.Twelve fresh human T11-L3 spinal specimens were harvested in this study. The 1/3 L1 vertebral body was resected in a wedged shape. After the preinjury had been created, the specimens were subjected to flexion-compression to create a fracture model. Resection of the ligaments was performed in a sequential manner from the bilateral facet capsule ligament (FCL), interspinous ligament, and supraspinous ligament (SSL) to the ligamentum flavum at the T12-L1 level. Then, for the intact specimen, fracture model, and ligament disruption steps, the range of motion (ROM) and neutral zone (NZ) of T12-L1 and L1-L2 were collected for each simulated movement.Sequential transection of the posterior ligamentous complex (PLC), ROM, and NZ were increased in all movements at the T12-L1 segment. In the flexion-extension (FE), the ROM and NZ demonstrated significant increases after the fracture model and resection of SSL and LF. In lateral bending (LB), the ROM increased after the fracture and removal of the LF, while the NZ showed a slight increase. In axial rotation, the fracture model and removal of the LF resulted in a significant increase in the ROM, and the NZ showed a slight change after step reduction. For the L1-L2 segment, resection of the FCL led to an increased ROM in LB.With rupture of SSL or LF, the stability of the segment decreased significantly compared with the intact and fracture model, particularly in FE motion, the function of the PLC was considered to be incompetent.

Does Surgical Intervention or Timing of Surgery Have an Effect on Neurological Recovery in the Setting of a Thoracolumbar Burst Fracture?

Traumatic thoracolumbar burst fractures are one of the most common forms of spinal trauma with the majority occurring at the junctional area where mechanical load is maximal (AOSpine Thoracolumbar Spine Injury Classification System Subtype A3 or A4). Burst fractures entail the involvement of the middle column, and therefore, they are typically associated with bone fragment in the spinal canal, which may cause compression of the spinal cord, conus medullaris, cauda equina, or a combination of these. Fortunately, approximately half of the patients with thoracolumbar burst fractures are neurologically intact due to the wide canal diameter. Recent evidences have revealed that functional outcomes in the long term may be equivalent between operative and nonoperative management for neurologically intact thoracolumbar burst fractures. Nevertheless, consensus has not been met regarding the optimal treatment strategy for those with neurological deficits. The present review article summarizes the contemporary evidences to discuss the role of nonoperative management in the presence of neurological deficits and the optimal timing of decompression surgery for neurological recovery. In summary, although operative management is generally recommended for thoracolumbar fracture with significant neurological deficits, the evidence is weak, and nonoperative management can also be an option for those with solitary radicular symptoms. With regards to timing of operative management, high-quality studies comparing early and delayed intervention are lacking. Extrapolating from the evidence in cervical spine injury leads to an assumption that early intervention would also be beneficial for neurological recovery, but further studies are warranted to answer these questions.

[Long term radiological outcomes of unstable thoraco-lumbar fractures without neurological deficit]

OBJECTIVE

To analyse the radiological outcomes in the long term of unstable thoraco-lumbar fractures.

MATERIAL AND METHODS

Retrospective review of 100 patients with unstable thoracolumbar fractures treated with posterolateral fusion and short screw fixation for compression and flexion-distraction type fractures, and long segment posterior fixation for fractures-dislocations or more than one vertebra fractured, between 2000 and 2010 at three different hospital centers. Six radiological parameters were measured annually during a 4-year period: Fracture angle, kyphotic deformity, sagittal index, percentage of compression, degree of displacement and deformation angle.

RESULTS

A total of 100 patients were included with a median age of 36,4 years and a median follow-up period of 7.2 years. Fracture angle rose from 11,6° to 14,5° (increase of 25%), kyphotic deformity from 14,5° to 16,7° (increase of 15,17%), sagittal index from 8,7 to 10,8 (increase of 24,13%), percentage of compression from 31,8% to 36,5% (increase of 6,88%), degree of displacement from 2,8mm to 4,6mm (increase of 14,77%) and deformation angle from 19.7° to 21.4° (increase of 8,62%).

DISCUSSION

All the radiological parameters studied lost correction throughout the 48 months of follow-up, being the fracture angle the most affected one. Nevertheless, the greatest loss of correction occurs in the first postoperative year, stabilizing the parameters afterwards over the 4 years of follow up. We routinely recommend the measurement of all previous parameters for the follow up of unstable thoracolumbar fractures.

Biomechanical properties of posterior transpedicular-transdiscal oblique lumbar screw fixation with novel trapezoidal lateral interbody spacer: an in vitro human cadaveric model

PURPOSE

To investigate biomechanical properties of posterior transpedicular-transdiscal (TPTD) oblique lumbar screw fixation whereby the screw traverses the inferior pedicle across the posterior disc space into the super-adjacent body and lateral trapezoidal interbody spacer.

METHODS

Eight fresh-frozen osteoligamentous human cadaveric spines (L1-S1) were tested in flexion-extension (FE), lateral bending (LB), and axial rotation (AR), with pure bending moment set at 7.5 Nm. Surgical constructs included (1) intact spine; (2) bilateral pedicle screw (BPS) fixation at L3-L4; (3) TPTD screw fixation at L3-L4; (4) lateral L3-L4 discectomy; (5) TPTD screw fixation with lateral interbody spacer (TPTD+S); and (6) BPS fixation with lateral interbody spacer (BPS+S). Peak range of motion (ROM) at L3-L4 was normalized to intact for statistical analysis.

RESULTS

In FE and LB, all posterior fixation with or without interbody spacers significantly reduced motion compared with intact and discectomy. BPS and BPS+S provided increased fixation in all planes of motion; significantly reducing FE and LB motion relative to TPTD (p = 0.005, p = 0.002 and p = 0.020, p = 0.004, respectively). In AR, only BPS significantly reduced normalized ROM to intact (p = 0.034); BPS+S provided greater fixation compared with TPTD+S (p = 0.005).

CONCLUSIONS

Investigators found less stiffness with TPTD screw fixation than with BPS regardless of immediate stabilization with lateral discectomy and spacer. Clinical use should be decided by required biomechanical performance, difficulty of installation, and extent of paraspinal tissue disruption.

Temporary stabilization of unstable spine fractures

PURPOSE OF REVIEW

We will review the recent literature concerning the necessity of supplemental fusion to spinal instrumentation and discuss if temporal spinal fixation is a viable option for the treatment of unstable spine fractures. Advancements in minimally invasive techniques offer an alternative approach to traditional open stabilization for unstable spine fractures. The use of minimally invasive surgery offers many advantages concerning operative morbidly; fusion is not utilized and instrumentation can be removed in a delayed fashion.

RECENT FINDINGS

There are limited differences in amount of correction loss over time, and multiple studies report equivocal to superior results in patient's functional outcomes when comparing temporary internal stabilization to long segment instrumentation with fusion. Removal of implants can restore segmental motion. Review of the literature demonstrates that temporary internal stabilization for unstable fractures is a viable option. Close clinical and radiographic follow-up is recommended to avoid delayed spinal deformity.

RETROSPECTIVE COMPARATIVE ANALYSIS OF SURGICAL TREATMENT OF THORACOLUMBAR BURST FRACTURE: SHORT VERSUS LONG FIXATION

ABSTRACT Objective: The objective of this study is to compare short posterior fixation to long posterior fixation in thoracolumbar burst fractures. Methods: Fifty-three patients were divided into Group I (n=24) treated with short instrumentation (one level above and one below the fracture) and into Group II (n=29) treated with long instrumentation (two or more levels above and below the fracture). The load sharing classification was used to stratify cases. The evaluation of the sagittal index was performed using the Cobb method. Results: In subgroups with load sharing classification ≤ 6, Group I had loss of correction of 4.2 degrees and a procedure failure in 14.3% of cases, Group II showed loss of correction of 5.4 degrees and failure in 21.7% of cases. In subgroups with load sharing classification ≥7, Group I had a loss of correction of 11.2 degrees and procedure failure in 70% of cases, and Group II showed a loss of correction of 9 degrees and failure of 46.7%. Group I had a tendency to worse outcomes, especially in the subgroup of patients with load sharing classification ≥7. Conclusion: Despite the tendency for poorer results in the short fixation group in the cases with load sharing ≥7, in no sample was there statistically significant difference between the groups studied.

Osteoporotic thoracolumbar junctional fracture accompanied by spinous process fracture without posterior ligament injury: its clinical and radiologic significances

PURPOSE

To assess the clinical and radiologic outcome of osteoporotic thoracolumbar junctional fracture accompanied by spinous process fracture (SPF) without posterior ligament injury.

METHODS

A total of 391 patients with single-level osteoporotic thoracolumbar junctional (T10-L2) fracture were selectively enrolled. The patients were divided into two groups by absence (group I) or presence (group II) of SPF. Clinical and radiologic parameters were compared between the two groups.

RESULTS

Group I comprised of 332 patients with only vertebral body fracture, and group II comprised of 59 patients with both vertebral body and SPFs. In all cases of group II, SPFs were located just one level above the fractured vertebral body, and the injury of the posterior ligament was not found. At the time of injury, group II patients showed worse outcomes in anterior vertebral body compression percentage, kyphotic Cobb angle, cranial disk status, and the rate of the initial neurologic injury. Kyphotic alignment changes during 1-year follow-up were compared between the conservative subgroups of groups I and II. At the time of injury, there were no statistical differences in anterior vertebral body compression percentage and Cobb angle between the two conservative subgroups. However, the difference was significant after 1-year follow-up. Comparison of kyphotic alignment change at 12 months after diagnosis within group II was done according to the treatment method. Vertebroplasty subgroup in group II did not show benefit even in preventing such kyphotic alignment change, whereas instrumentation subgroup in group II showed lordotic alignment restoration despite more severe kyphotic alignment at the time of injury.

CONCLUSIONS

Osteoporotic thoracolumbar junctional fracture accompanied by spinous process fracture without posterior ligament injury represented more severe injury with flexion forces on the anterior column and tensile forces on the posterior column, and was related with more severe posttraumatic kyphotic changes during the 12-month follow-up.

Changing threshold for AIS scores of thoracolumbar compression fractures

BACKGROUND

The Abbreviated Injury Scale (AIS) is an anatomical-based coding system created by the Association for the Advancement of Automotive Medicine, utilized to classify and code injuries resulting from trauma, in order of severity. According to the latest version, all Thoraco-Lumbar Compression Fractures (TLCF), even without injury to other spine components and with >20% loss of height, were branded AIS 3 injuries, reflecting a serious threat to life or permanent disability. Advances in spine imaging, recent biomechanical studies, and long-term outcomes research offer the opportunity to consider these injuries differently.

OBJECTIVE

To re-evaluate the percent compression threshold of TLCF of the spine from motor vehicle crashes (MVC) for serious risk to life identified as surgical treatment, delineating a reliable cut-off for fracture severity and morbidity. Little national data considers degree of compression and provides adequate followup imaging to determine degree of compression, justifying this effort.

METHODS

Charts and radiographs of patients admitted to our institution due to vehicle crashes with isolated (vertebral body only) TLCF between 2008 and 2015 were reviewed. Data were collected on degree of compression, treatment, and long-term outcomes to determine the threshold of permanent injury. Vertebral bodies at the level of fracture were measured both anteriorly and posteriorly, and compared to adjacent segments; percentage compression was calculated.

RESULTS

1470 patient records with diagnoses of spine trauma were reviewed; 695 isolated compression fractures were identified, of which 194 were in vehicle crashes and had adequate imaging and follow-up. Ages ranged from 19 to 82, with a male: female ratio of 60:40. No patient with vertebral body compression of less than 30% underwent surgery unless presenting with a neurological deficit. All 22 surgical patients demonstrated significant retropulsion of bone into the spinal canal. Five surgical patients suffered eight complications; there were no adverse outcomes in the nonsurgical group.

CONCLUSIONS

These results are consistent with evolving clinical thinking, resulting in decreasing surgical incidence and orthosis use. Our data strongly suggests that isolated compression fractures in the absence of neurologic deficit or severe cord compression due to retropulsed bone are self-limiting. Therefore, the AIS scores for these common injuries could be reconsidered and reflect their relatively benign outlook.

Imaging of Spine Trauma

Imaging with computed tomography and magnetic resonance imaging is fundamental to the evaluation of traumatic spinal injury. Specifically, neuroradiologic techniques show the exact location of injury, evaluate the stability of the spine, and determine neural element compromise. This review focuses on the complementary role of different radiologic modalities in the diagnosis of patients with traumatic injuries of the spine. The role of imaging in spinal trauma classifications will be addressed. The importance of magnetic resonance imaging in the assessment of soft tissue injury, particularly of the spinal cord, will be discussed. Last, the increasing role of advanced imaging techniques for prognostication of the traumatic spine will be explored.