The surgical algorithm for the AOSpine thoracolumbar spine injury classification system

Which spinal fixation technique achieves which degree of stability after thoracolumbar trauma? A systematic quantitative review

BACKGROUND CONTEXT

Unstable traumatic spinal injuries require surgical fixation to restore biomechanical stability.

PURPOSE

The purpose of this review was to summarize and quantify three-dimensional spinal stability after surgical fixation of traumatic thoracolumbar spinal injuries using different treatment strategies derived from experimental studies.

STUDY DESIGN/SETTING

Systematic literature review.

METHODS

Keyword-based search was performed in PubMed and Web of Science databases to identify all in vitro studies investigating stabilizing effects of different surgical fixation strategies for the treatment of traumatic spinal injuries of the thoracolumbar spine. Biomechanical stability parameters such as range of motion, neutral zone, and translation, as well as the experimental design were extracted, collected, and evaluated with respect to the type and level of injury and treatment strategy.

RESULTS

A total of 66 studies with human specimens were included in this review, of which 16 studies examined the treatment of incomplete (AOSpine A3) and 34 studies the treatment of complete burst fractures (AOSpine A4). Fixations of wedge fractures (AOSpine A1, n=5 studies), ligament injuries (AOSpine B, n=7 studies), and three-column injuries (AOSpine C, n=7 studies) were investigated less frequently. Treatment approaches could be divided into five subgroups: Posterior fixation, e.g. posterior pedicle screw systems, anterior fixation, e.g. anterolateral plate fixation, combined anterior-posterior fixation, vertebral body replacement with additional instrumentation, and augmentation techniques, e.g. vertebroplasty and kyphoplasty. Minor injuries were generally treated with less invasive surgical methods such as augmentative and posterior approaches. Bisegmental posterior pedicle screw fixation led to stabilization of minor compression injuries, whereas in more severe injuries, e.g. AOSpine A4 or AOSpine C, instability remained in at least one motion plane. More invasive fixation techniques such as long segment posterior fixation, circumferential fixation, or vertebral body replacements with circumferential fixation provided total stabilization in terms of range of motion reduction even in more severe injuries. Pure augmentative treatment did not restore multidirectional stability. Neutral zone, which was reported in 25 studies, generally exhibited higher remaining increase than range of motion, which was reported in all 66 studies. Instability characteristics after treatment differed with respect to the spinal region, as thoracic injuries were more likely to remain unstable in flexion/extension, while thoracolumbar and lumbar injuries exhibited remaining instability primarily in axial rotation.

CONCLUSIONS

The stabilizing effect of surgical treatment depends on the type, severity, and location of injury, as well as the fixation strategy. There is an enormous range of surgical approaches and instrumentation strategies available. Pure augmentative techniques have not been able to restore complex multidimensional stability in traumatic spinal injuries. More invasive fixation approaches such as circumferential instrumentation or vertebral body replacement constructs together with posterior or anterior-posterior fixation offer more stability even in severe spinal injuries. Future studies are required to expand the knowledge especially regarding the stabilization of minor compression injuries, ligament injuries, and rotational injuries.

How reliable is the distinction between thoracolumbar AO type A3 and A4 fractures? A systematic literature review

PURPOSE

The AOSpine classification divides thoracolumbar burst fractures into A3 and A4 fractures; nevertheless, past research has found inconsistent interobserver reliability in detecting those two fracture patterns. This systematic analysis aims to synthesize data on the reliability of discriminating between A3 and A4 fractures.

METHODS

We searched PubMed, Scopus, and the Web of Science for studies reporting the inter- and intra-observer reliability of detecting thoracolumbar AO A3 and A4 fractures using computed tomography (CT). The search spanned 2013 to 2023 and included both primarily reliability and observational comparative studies. We followed the PRISMA guidelines and used the modified COSMIN checklist to assess the studies' quality. Kappa coefficient (k) values were categorized according to Landis and Koch, from slight to excellent.

RESULTS

Of the 396 identified studies, nine met the eligibility criteria; all were primarily reliability studies except one observational study. Interobserver k values for A3/A4 fractures varied widely among studies (0.19-86). The interobserver reliability was poor in two studies, fair in one study, moderate in four studies, and excellent in two studies. Only two studies reported intra-observer reliability, showing fair and excellent agreement. The included studies revealed significant heterogeneity in study design, sample size, and interpretation methods.

CONCLUSION

Considerable variability exists in interobserver reliability for distinguishing A3 and A4 fractures from slight to excellent agreement. This variability might be attributed to methodological heterogeneity among studies, limitations of reliability analysis, or diagnostic pitfalls in differentiating between A3 and A4. Most observational studies comparing the outcome of A3 and A4 fractures do not report interobserver agreement, and this should be considered when interpreting their results.

Traumatic thoracic spine fracture: can we predict when MRI would modify the fracture classification or decision-making compared to CT alone?

PURPOSE

To determine the impact of magnetic resonance imaging (MRI) on fracture classification for thoracic spine fractures (TSFs) compared to computed tomography (CT) alone.

METHODS

This study was a retrospective review of 63 consecutive patients with TSFs who underwent CT and MRI within ten days of injury. Three reviewers classified all fractures according to the AOSpine Classification and the Thoracolumbar AOSpine Injury severity score (TLAOSIS). Posterior ligamentous complex (PLC) injury on MRI was defined by "black stripe discontinuity" and on CT by the presence of vertebral body translation, facet joint malalignment, horizontal laminar or spinous process fracture, and interspinous widening. The proportion of patients with AO type A/B/C and with TLAOSIS ≤ 5 and ≥ 6 was compared between CT and MRI. Classification and regression trees were used to create a series of predictive models for the probability of PLC injury in AO type A fractures.

RESULTS

AO classification using CT was as follows: type A in 35 patients (55%), type B in 18 patients (29%), and type C in 10 patients (16%). Thirty-three patients (52%) had a TLAOSIS ≤5, while the remaining 30 (48%) had TLAOSI ≥6. The addition of MRI after CT upgraded type A to type B fractures in 10 patients (16%) and changed TL AOSIS from ≤5 to ≥6 in 8 cases (12.8%). Type A fractures with load sharing score (LSC) ≥6 had a 60% chance of upgrading to type B, while LSC <6 had a 12.5% chance of upgrading to type B.

CONCLUSIONS

CT yielded (89%) accuracy in diagnosing PLC injury in TSFs. The addition of MRI after CT substantially changed the AO classification or TLAOISS, compared to CT alone, thus suggesting an added value of MRI for PLC assessment for TSFs classification.

Thoracolumbar injuries: prehospital and emergency management, imaging, classifications and clinical implications

Thoracolumbar fractures are common injuries that usually result from high energy trauma. They can lead to significant morbidity due to neurologic impair - or mortality - if not managed according to strict and rapid intervention rules in terms of decompression of the spinal cord, and rigid fixation of the fracture. This manuscript reviews emergency treatment protocols, imaging modalities, and classification systems used for thoracolumbar fractures. The emergency treatment is discussed, specific classifications are compared and indications for surgeries are compared.

Evaluation and Management of Thoracolumbar Spine Trauma in Pediatric Patients: A Critical Analysis Review

» Pediatric thoracolumbar trauma, though rare, is an important cause of morbidity and mortality and necessitates early, accurate diagnosis and management.» Obtaining a detailed history and physical examination in the pediatric population can be difficult. Therefore, the threshold for advanced imaging, such as magnetic resonance imaging, is low and should be performed in patients with head injuries, altered mental status, inability to cooperate with examination, and fractures involving more than 1 column of the spine.» The classification of pediatric thoracolumbar trauma is based primarily on adult studies and there is little high-level evidence examining validity and accuracy in pediatric populations.» Injury pattern and neurologic status of the patient are the most important factors when determining whether to proceed with operative management.

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.

How does vertical laminar fracture impact the decision-making in thoracolumbar fractures? A systematic scoping review and meta-analysis

OBJECTIVE

Although vertical laminar fracture (VLF) is generally considered a severity marker for thoracolumbar fractures (TLFs), its exact role in decision-making has never been established. This scoping review aims to synthesize the research on VLF's role in the decision-making of TLFs.

METHODS

A systematic review was conducted following PRISMA guidelines. We searched PubMed, Scopus, and Web of Science from inception to  June 11, 2023, for studies examining the association of VLF in thoracolumbar fractures with dural lacerations, neurological deficits, radiographic parameters, or treatment outcomes. Additionally, experimental studies that analyze the biomechanics of burst fractures with VLF were included. The studies extracted key findings, objectives, and patient population. A meta-analysis was performed for the association of VLF with dural laceration and neurological deficit, and ORs were pooled with a 95% confidence interval (CI).

RESULTS

Twenty-eight studies were included in this systematic review, encompassing 2021 patients, and twelve were included in the meta-analysis. According to the main subject of the study, the association of VLF with a dural laceration (n = 14), neurological deficit (n = 4), radiographic parameters (n = 3), thoracolumbar fracture classification (n = 2), and treatment outcome (n = 2). Seven studies with a total of 1010 patients reported a significant association between VLF and neurological deficit (OR = 7.35, 95% CI [3.97, 14.25]; P < 0.001). The pooled OR estimates for VLF predicting dural lacerations were 7.75, 95% CI [2.41, 24.87]; P < 0.001).

CONCLUSION

VLF may have several important diagnostic and therapeutic implications in managing TLFs. VLF may help to distinguish AO type A3 from A4 fractures. VLF may help to predict preoperatively the occurrence of dural laceration, thereby choosing the optimal surgical strategy. Clinical and biomechanical data suggest VLF may be a valuable modifier to guide the decision-making in burst fractures; however, more studies are needed to confirm its prognostic importance regarding treatment outcomes.

Global Validation of the AO Spine Upper Cervical Injury Classification: Geographic Region Affects Reliability and Reproducibility

STUDY DESIGN

Global Survey.

OBJECTIVE

To determine the accuracy, interobserver reliability, and intraobserver reproducibility of the AO Spine Upper Cervical Injury Classification System based on surgeons' AO Spine region of practice (Africa, Asia, Central/South America, Europe, Middle East, and North America).

METHODS

A total of 275 AO Spine members assessed 25 upper cervical spine injuries and classified them according to the AO Spine Upper Cervical Injury Classification System. Reliability, reproducibility, and accuracy scores were obtained over two assessments administered at three-week intervals. Kappa coefficients (ƙ) determined the interobserver reliability and intraobserver reproducibility.

RESULTS

On both assessments, participants from Europe and North America had the highest classification accuracy, while participants from Africa and Central/South America had the lowest accuracy (P < .0001). Participants from Africa (assessment 1 (AS1):ƙ = .487; AS2:0.491), Central/South America (AS1:ƙ = .513; AS2:0.511), and the Middle East (AS1:0.591; AS2: .599) achieved moderate reliability, while participants from North America (AS1:ƙ = .673; AS2:0.648) and Europe (AS1:ƙ = .682; AS2:0.681) achieved substantial reliability. Asian participants obtained substantial reliability on AS1 (ƙ = .632), but moderate reliability on AS2 (ƙ = .566). Although there was a large effect size, the low number of participants in certain regions did not provide adequate certainty that AO regions affected the likelihood of participants having excellent reproducibility (P = .342).

CONCLUSIONS

The AO Spine Upper Cervical Injury Classification System can be applied with high accuracy, interobserver reliability, and intraobserver reproducibility. However, lower classification accuracy and reliability were found in regions of Africa and Central/South America, especially for severe atlas injuries (IIB and IIC) and atypical hangman's type fractures (IIIB injuries).

Towards a standardized reporting of the impact of magnetic resonance imaging on the decision-making of thoracolumbar fractures without neurological deficit: Conceptual framework and proposed methodology

Introduction

A recent meta-analysis showed that only four prior studies have shown that magnetic resonance imaging (MRI) can change the fracture classification in 17% and treatment decisions in 22% of cases. However, previous studies showed a wide methodological variability regarding the study population, the definition of posterior ligamentous complex (PLC) injury, and outcome measures.

Research question

How can we standardize the reporting of the impact of MRI for neurologically intact patients with thoracolumbar fractures?

Material and methods

All available literature regarding the impact of MRI on thoracolumbar fracture classification or decision-making were reviewed. Estimating the impact of MRI on the TLFs' classification is an exercise of analyzing the CTs' accuracy for PLC injury against MRI as a ''Gold standard''and should follow standardized checklists such as the Standards for the Reporting of Diagnostic Accuracy Studies. Additionally, specific issues related to TLFs should be addressed.

Results

A standardized approach for reporting the impact of MRI in neurologically intact TLF patients was proposed. Regarding patient selection, restricting the inclusion of neurologically intact patients with A- and B-injuries is crucial. Image interpretation should be standardized regarding imaging protocol and appropriate criteria for PLC injury. The impact of MRI can be measured by either the rate of change in fracture classification or treatment decisions; the cons and pros of each measure is thoroughly discussed.

Discussion and conclusion

We proposed a structured methodology for examining the impact of MRI on neurologically intact patients with TLFs, focusing on appropriate patient selection, standardizing image analysis, and clinically relevant outcome measures.

Surgical outcomes of anterior column reconstruction for spinal fractures caused by minor trauma-preoperative examination of the number of intervertebral bone bridges is key to obtaining good bone fusion

BACKGROUND

To achieve good bone fusion in anterior column reconstruction for vertebral fractures, not only bone mineral density (BMD) and bone metabolism markers but also lever arms due to bone bridging between vertebral bodies should be evaluated. However, until now, no lever arm index has been devised. Therefore, we believe that the maximum number of vertebral bodies that are bony and cross-linked with the contiguous adjacent vertebrae (maxVB) can be used as a measure for lever arms. The purpose of this study is to investigate the surgical outcomes of anterior column reconstruction for spinal fractures and to determine the effect of bone bridging between vertebral bodies on the rate of bone fusion using the maxVB as an indicator of the length of the lever arm.

METHODS

The clinical data of 81 patients who underwent anterior column reconstruction for spinal fracture between 2014 and 2022 were evaluated. The bone fusion rate, back pain score, between the maxVB = 0 and the maxVB ≥ 2 patients were adjusted for confounding factors (age, smoking history, diabetes mellitus history, BMD, osteoporosis drugs, surgical technique, number of fixed vertebrae, materials used for the anterior props, etc.) and analysed with multivariate or multiple regression analyses. The bone healing rate and incidence of postoperative back pain were compared among the three groups (maxVB = 0, 2≦maxVB≦8, maxVB ≧ 9) and divided by the maxVB after adjusting for confounding factors.

RESULTS

Patients with a maxVB ≥ 2 had a significantly higher bone fusion rate (p < 0.01) and postoperative back pain score (p < 0.01) than those with a maxVB = 0. Among the three groups, the bone fusion rate and back pain score were significantly higher in the 2≦maxVB≦8 group (p = 0.01, p < 0.01).

CONCLUSIONS

Examination of the maxVB as an indicator of the use of a lever arm is beneficial for anterior column reconstruction for vertebral fractures. Patients with no intervertebral bone bridging or a high number of bone bridges are in more need of measures to promote bone fusion than patients with a moderate number of bone bridges are.

Comparative Outcomes of Percutaneous and Conventional Open Pedicle Screw Fixation for Single-level Thoracolumbar Spine Injury: Randomised Controlled Trial

Introduction

To compare post-operative outcomes of percutaneous pedicle screw fixation (PPSF) vs open pedicle screw fixation (OPSF) in patients with thoracolumbar spine fractures with no neurological deficits.

Materials and methods

In a randomised controlled trial, patients received short-segment fixation with intermediate screws. We assessed post-operative back pain (Visual Analog Scale or VAS), blood loss, operative/fluoroscopy times, radiographic parameters, and oswestry disability index (ODI) scores at 1, 2, 3, 6, 9, and 12 months.

Results

Between January 2018 and October 2019, 31 patients received PPSF and 30 OPSF. Mean intra-operative blood loss was 66.45 (±44.29) ml for PPSF vs 184.83 (±128.36) ml for OPSF (p<0.001). Fluoroscopy time averaged 2.36 (±0.76) minutes for PPSF vs 0.58 (±0.51) minutes for OPSF (p<0.001). No significant differences existed in operative time or post-operative VAS scores. Radiographic parameters (kyphosis angle and vertebral height ratios) didn't significantly differ post-operatively or at 12 months. However, ODI scores differed significantly at 6 months (p=0.025), with no difference at 12 months.

Conclusion

In this trial, PPSF was comparable to OPSF in improving ODI scores at 12 months but showed earlier improvement at 6 months and reduced blood loss. Radiographic outcomes remained similar between groups over 12 months.

The Surgical Algorithm for the AO Spine Sacral Injury Classification System

STUDY DESIGN

Global cross-sectional survey.

OBJECTIVE

To establish a surgical algorithm for sacral fractures based on the Arbeitsgemeinschaft für Osteosynthesefragen (AO) Spine Sacral Injury Classification System.

SUMMARY OF BACKGROUND DATA

Although the AO Spine Sacral Injury Classification has been validated across an international audience of surgeons, a consensus on a surgical algorithm for sacral fractures using the Sacral AO Spine Injury Score (Sacral AOSIS) has yet to be developed.

METHODS

A survey was sent to general orthopedic surgeons, orthopedic spine surgeons, and neurosurgeons across the five AO spine regions of the world. Descriptions of controversial sacral injuries based on different fracture subtypes were given, and surgeons were asked whether the patient should undergo operative or nonoperative management. The results of the survey were used to create a surgical algorithm based on each subtype's sacral AOSIS.

RESULTS

An international agreement of 70% was decided on by the AO Spine Knowledge Forum Trauma experts to indicate a recommendation of initial operative intervention. Using this, sacral fracture subtypes of AOSIS 5 or greater were considered operative, while those with AOSIS 4 or less were generally nonoperative. For subtypes with an AOSIS of 3 or 4, if the sacral fracture was associated with an anterior pelvic ring injury (M3 case-specific modifier), intervention should be left to the surgeons' discretion.

CONCLUSION

The AO Spine Sacral Injury Classification System offers a validated hierarchical system to approach sacral injuries. Through multispecialty and global surgeon input, a surgical algorithm was developed to determine appropriate operative indications for sacral trauma. Further validation is required, but this algorithm provides surgeons across the world with the basis for discussion and the development of standards of care and treatment.

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.

Computed Tomography Findings and Classification of Traumatic Lumbosacral Spine Injuries: Insights from the AOSpine Classification System

Purpose

The main objective of this study was to provide a description and classification of lumbosacral spine injuries based on the new AOSpine classification system.

Methods

A cross-sectional study was conducted on 75 patients with lumbosacral spine trauma who were admitted to Hue University of Medicine and Pharmacy Hospital in Hue, Vietnam, between April 2021 and July 2022. All patients underwent lumbosacral computed tomography, and each injured vertebra was classified according to the AOSpine classification system. The frequency and percentage of subtypes of lumbosacral spine trauma were determined.

Results

The mean age of the patients was 50.6 ± 16.1 years, and the male-to-female ratio was 1.5:1. Falls and traffic accidents were found to be the main causes of injuries. Among the patients, 78.7% did not exhibit any neurological symptoms, while 1.3% experienced complete hemiplegia and 20% had incomplete hemiplegia. The most common fracture subtype was A3, accounting for 34.6% of cases.

Conclusion

This study provides valuable insights into the demographics, associated injuries, and classification of traumatic lumbosacral spine injuries based on the new AOSpine classification system. The study found that falls and motor vehicle accidents were the main causes of these injuries, with a higher proportion of male patients. The majority of injuries were classified as type A fractures, while type C fractures were the least common. Sacral fractures were relatively infrequent and often associated with pelvic ring fractures. These findings contribute to our understanding of lumbosacral spine trauma and can aid in the development of more effective treatment protocols.

Functionalization of Osteoplastic Material with Human Placental Growth Factor and Assessment of Biocompatibility of the Resulting Material In Vitro

This article provides the results of a study of the interaction of placental growth factor with adipose-derived stem cells (ASCs) of various origins, as well as the possibility of generating osteoplastic material based on xenogeneic matrix functionalization with human placental growth factor (PLGF). It is demonstrated that the greatest release of this factor from the functionalized material into the medium occurs during the first 3 h of contact with the model medium, but then the levels of the factor being released fall sharply, although release did continue throughout the 7 days of observation. The modified material was not cytotoxic, and its surface provided good cell adhesion. During 3 days of cultivation, the ASCs proliferated and migrated more actively on the surfaces of the modified material than on the surfaces of the control material. This study can serve as the basis for the development of original methods to functionalize such osteoplastic material by increasing PLGF immobilization by creating stronger bonds in order to regulate both factor dosage and the dynamics of the factor release into the environment. Further studies in experimental animals should facilitate assessment of the effectiveness of the functionalized materials. Such studies will be useful in the development of osteoplastic materials with new properties resulting from the inclusion of growth factors and in research on their biological activity.

Surgical treatment of traumatic fractures of the thoracic and lumbar spine: A systematic review

Introduction

The treatment of traumatic thoracic and lumbar spine fractures remains controversial. To date no consensus exists on the correct choice of surgical approach and technique.

Research question

to provide a comprehensive up-to-date overview of the available different surgical methods and their quantified outcomes.

Methods

PubMed and EMBASE were searched between 2001 and 2020 using the term 'spinal fractures'. Inclusion criteria were: adults, ≥10 cases, ≥12 months follow-up, thoracic or lumbar fractures, and surgery <3 weeks of trauma. Studies were categorized per surgical technique: Posterior open (PO), posterior percutaneous (PP), stand-alone vertebral body augmentation (SA), anterior scopic (AS), anterior open (AO), posterior percutaneous and anterior open (PPAO), posterior percutaneous and anterior scopic (PPAS), posterior open and anterior open (POAO) and posterior open and anterior scopic (POAS). The PO group was used as a reference group.

Results

After duplicate removal 6042 articles were identified. A total of 102 articles were Included, in which 137 separate surgical technique cohorts were described: PO (n = 75), PP, (n = 39), SA (n = 12), AO (n = 5), PPAO (n = 1), PPAS (n = 1), POAO (n = 2) and POAS (n = 2).

Discussion and conclusion

For type A3/A4 burst fractures, without severe neurological deficit, posterior percutaneous (PP) technique seems the safest and most feasible option in the past two decades. If needed, PP can be combined with anterior augmentation to prevent secondary kyphosis. Furthermore, posterior open (PO) technique is feasible in almost all types of fractures. Also, this technique can provide for an additional posterior decompression or fusion. Overall, no neurologic deterioration was reported following surgical intervention.

Da Vinci Robotic Assistance for Anterolateral Lumbar Arthrodesis: Results of a French Multicentric Study

BACKGROUND

The da Vinci robot (DVR) is the most widely used robot in abdominal, urological, and gynecological surgery. Due to its minimally invasive approach, the DVR has demonstrated its effectiveness and improved safety in these different disciplines. The aim of our study was to report its use in an anterior approach of complex lumbar surgery.

METHODS

In a retrospective multicenter observational study, 10 robotic-assisted procedures were performed from March 2021 to May 2022. Six oblique lumbar interbody fusion procedures and 4 lumbar corpectomies were performed by anterolateral approach assisted by the DVR. The characteristics of the patients and the intraoperative and postoperative data were recorded.

RESULTS

Six men and 4 women underwent surgery (mean age 50.5 years; body mass index 28.6 kg/m2). No vascular injuries were reported, and no procedures required conversion to open surgery. Mean surgical time were 219 minutes for 1-level oblique lumbar interbody fusion (3 patients), 286 minutes for 2-level oblique lumbar interbody fusion (3 patients), and 390 minutes for corpectomy (4 patients). Four patients experienced nonserious adverse events due to lumbar plexus nerve damage. One patient had a vertebral body plate fracture requiring posterior revision surgery, and 1 patient had a psoas hematoma requiring transfusion. No abdominal wall complications or surgical site infection were found. Seven patients were reviewed at 12 months, none had complications, and all showed radiological evidence of fusion.

CONCLUSIONS

The use of the DVR in lumbar surgery allows a safe minimally invasive transperitoneal approach, but to date, only hybrid procedures have been performed.

How Often Would MRI Change the Thoracolumbar Fracture Classification or Decision-Making Compared to CT Alone?

STUDY DESIGN

retrospective study of consecutive patients.

OBJECTIVE

to analyze the frequency of change in Thoracolumbar fractures (TLFs) classification or decision-making after MRI compared by CT alone.

METHODS

A retrospective review of 244 consecutive patients with acute TLFs (T1-L5) presented to a single level 1 trauma center between 2014 and 2021. Three and 4 reviewers independently classified all fractures according to AOSpine and AOSpine injury severity score (TLAOSIS) by CT then MRI, respectively. Posterior ligamentous complex Injury (PLC) was diagnosed on CT and MRI by ≥ 2 positive CT findings and Black stripe discontinuity.

RESULTS

MRI changed AO classification in 25/244 patients (10.2%, P < .0001) due to an 8.2% upgrade from type A to type B and a 2% downgrade from type B to type A. The addition of MRI changed TL AOSIS among the 3 treatment recommendation groups in 35/244 (19.7%, 95% CI [14.9%-25.2%]. The best predictor of upgrade from type A to type B and downgrade from type B to type A was a single positive CT finding and the presence of only 2 CT signs as opposed to ≥3 signs, respectively (P < .0001 P = .03, respectively). Thoracic fractures showed a significantly higher reclassification rate than thoracolumbar and low lumbar (20% vs 10% and 0%, respectively, P = .07).

CONCLUSION

using appropriate CT/MRI criteria for PLC injury, MRI changed the AOSpine classification by 10% and TLAOSIS based treatment by 19.7%. The best predictors of fracture reclassification by MRI were the number of positive CT findings and fracture level.

Successful implementation of prophylactic veno-venoarterial extracorporeal membrane oxygenation in high-risk trauma surgery: A case report

INTRODUCTION

Extracorporeal Membrane Oxygenation (ECMO) is increasingly utilized in trauma care, yet its elective use during high-risk surgeries remains unreported.

CASE REPORT

We report a successful instance of prophylactic ECMO support via a Veno-Venoarterial (V-VA) configuration during high-risk surgery in a patient with extensive trauma, including severe thoracic damage and a highly unstable thoracic spine fracture. V-VA ECMO prevented complications such as hemodynamic and respiratory collapse associated with chest compression during the surgical procedure, as the patient should be in a prone position.

DISCUSSION

The potential of ECMO as prophylactic support in high-risk surgery amongst trauma patients underscores a novel application of this technology. Complex configurations must be evaluated to avoid associated ECMO complications.

CONCLUSION

Our case highlights the potential of prophylactic ECMO hybrid modes, indicating their safe application during high-risk procedures in select trauma patients.

Thoracolumbar spine fracture patterns, etiologies, and treatment modalities in Jordan

Purpose

Spine fractures are a significant cause of long-term disability and socioeconomic burden. The incidence of spine fractures tends to increase with age, decreased bone density, and fall risk. In this study, we evaluated thoracolumbar fractures at a tertiary hospital in Jordan regarding their frequency, etiology, patterns, and treatment modalities.

Methods

The clinical and radiological records of 469 patients with thoracolumbar fracturesadmitted to King Hussein Medical City from July 2018 to August 2022 were evaluated regarding patients' age, sex, mechanism of injury, fracture level and pattern, and treatment modalities.

Results

The mean age of patients was 51.24±20.22 years, and men represented 52.7%. Compression injuries accounted for 97.2% of thoracolumbar fractures, and the thoracolumbar junction was the most common fracture location. Falling from the ground level was the most common mechanism and accounted for half of the injuries. Associated neurological injuries were identified in 3.8% of patients and were more common in younger patients. Pathological fractures were found in 12.4% and were more prevalent among elderly patients and women.

Conclusions

Traffic accidents and falling from height were the most common causes of spine fractures in patients younger than 40. However, 70% of spine fractures in women were caused by simple falls, reflecting the high prevalence of osteoporosis among women and the elderly. Therefore, traffic and work safety measures, as well as home safety measures and osteoporosis treatment for the elderly, should be recommended to reduce the risk of spine fractures.

A Novel Classification of Cervical Spine Trauma in Ankylosing Spondylitis and Corresponding Surgical Outcomes

OBJECTIVE

Currently, there are no reports on the specific classification of cervical spine trauma (CST) in ankylosing spondylitis (AS) based on the trauma mechanism. In this study, we aimed to describe a novel classification of CST in AS with more details, and put forward the corresponding surgical outcomes related to different types, hoping to provide a practical reference for clinical decision-making and academic communication.

METHODS

From January 2008 to December 2021, AS patients who experienced CST were retrospectively reviewed and included. Clinical data including gender, age, reason of trauma, time interval between AS diagnosis and trauma were collected. The American Spinal Injury Association (ASIA) grade system was used to describe patients' neurological status. Based on the combination of surgical experience and follow-up observation, the lower cervical spine trauma in AS patients was divided into three main types, namely single level fracture-dislocation (type 1), spinal cord injury without fracture-dislocation (type 2), and Andersson lesion (type 3). Furthermore, we performed detailed subtypes according to whether cervical spine was completely fused and the location of injury. Meanwhile, according to different approaches, surgical methods mainly included Anterior Cervical Discectomy and Fusion (ACDF), Anterior Cervical Corpectomy and Fusion (ACCF), Posterior Expansive Open-door Cervical Laminoplasty (PEOLP), Posterior Cervical Laminectomy Decompression and Fusion (PCLDF), and their combination. Postoperative general and surgery-related complications were also recorded.

RESULTS

A total of 102 patients were enrolled, including 91 males and 11 females, with an average age of 51.9 years. Their average interval time between AS diagnosis and injury was 27.8 years. Patients with high-energy and low-energy trauma were 54 and 48 respectively. There were 79 patients suffering spinal cord nerve impairment after trauma. With regard to the distribution of different types, the number of patients in type 1, type 2, and type 3 were 86, 14, and two, respectively. For different types, PCLDF was the most commonly used surgical method, accounting for 55.9%, while ACCF was only applied for one time. In type 1, the frequencies of ACDF, ACCF, PCLDF, and ACDF+PCLDF were 10.5%, 1.2%, 55.8%, and 32.5%. In type 2, the frequencies of ACDF, PCLDF, ACDF+PCLDF, and PEOLP were 7.1%, 50.0%, 7.1%, 35.8%. Postoperatively, 21 patients achieved neurological function improvement. The incidences of general and surgery-related complications were 19.6% and 5.9%, respectively. All patients achieved bone fusion and durable decompression at the last follow-up.

CONCLUSIONS

Our novel classification could enrich the scope of CST in AS patients and provide valuable references to the corresponding clinical management. Besides, there are strict indications of different surgical methods, factors like patient's physical condition, trauma type, surgical purpose, and expected efficacy were all required to consider before making a clinical decision.

Endoscopic Decompression Combined with Percutaneous Pedicle Screw Fixation for Treating Thoracolumbar Burst Fractures with Neurological Deficits: Technical Note and Early Outcomes

OBJECTIVE

The aim of this study is to introduce surgical technique of endoscopic decompression combined with percutaneous pedicle screw fixation (PPSF) for thoracolumbar burst fractures (TLBFs) with neurological deficits and evaluate its efficacy.

METHODS

A total of 32 patients with TLBFs and neurological deficits who were treated by endoscopic decompression combined with PPSF from June 2018 to August 2019 were included in this study. The effect of decompression was analyzed using canal encroachment ratio, while deformity correction was assessed using the sagittal Cobb angle and the percentage of anterior vertebral height. We also analyzed other clinical outcomes such as visual analog scale, Oswestry Disability Index, and American Spinal Injury Association impairment scale dose.

RESULTS

The patients were followed up for an average of 16 months. Our data showed that the patients' mean operation time was 153.75 minutes, the mean intraoperative blood loss was 48.84 mL, and the mean incision length was 7.78 cm. The canal encroachment ratio decreased from 55.91% ± 12.27% to 12.44% ± 3.91% (P < 0.05), sagittal Cobb angle decreased from 17.09° ± 5.46° to 5.72° ± 3.68° (P < 0.05), while the percentage of anterior vertebral height increased from 53.72% ± 8.99% to 83.22% ± 8.21% (P < 0.05). In addition, there was a significant improvement in the visual analog scale score, Oswestry Disability Index, and American Spinal Injury Association impairment scale classification (P < 0.05). Screw fracture occurred only in one patient during follow-up.

CONCLUSIONS

Endoscopic decompression combined with PPSF in the treatment of TLBFs with neurological deficits is safe and effective, which is a new minimally invasive method for the treatment of such diseases.

Clinical Evaluation of the Osteoporotic Fracture Treatment Score (OF-Score): Results of the Evaluation of the Osteoporotic Fracture Classification, Treatment Score and Therapy Recommendations (EOFTT) Study

STUDY DESIGN

Multicenter prospective cohort study.

OBJECTIVE

The study aims to validate the recently developed OF score for treatment decisions in patients with osteoporotic vertebral compression fractures (OVCF).

METHODS

This is a prospective multicenter cohort study (EOFTT) in 17 spine centers. All consecutive patients with OVCF were included. The decision for conservative or surgical therapy was made by the treating physician independent of the OF score recommendation. Final decisions were compared to the recommendations given by the OF score. Outcome parameters were complications, Visual Analogue Scale, Oswestry Disability Questionnaire, Timed Up & Go test, EQ-5D 5 L, and Barthel Index.

RESULTS

In total, 518 patients (75.3% female, age 75 ± 10) years were included. 344 (66%) patients received surgical treatment. 71% of patients were treated following the score recommendations. For an OF score cut-off value of 6.5, the sensitivity and specificity to predict actual treatment were 60% and 68% (AUC .684, P < .001). During hospitalization overall 76 (14.7%) complications occurred. The mean follow-up rate and time were 92% and 5 ± 3.5 months, respectively. While all patients in the study cohort improved in clinical outcome parameters, the effect size was significantly less in the patients not treated in line with the OF score's recommendation. Eight (3%) patients needed revision surgery.

CONCLUSIONS

Patients treated according to the OF score's recommendations showed favorable short-term clinical results. Noncompliance with the score resulted in more pain and impaired functional outcome and quality of life. The OF score is a reliable and save tool to aid treatment decision in OVCF.

Anterior thoracolumbar column reconstruction with the vertebral body stent-safety and efficacy

PURPOSE

The aim of this study was to assess safety and efficacy of vertebral body stenting (VBS) by analyzing (1) radiographic outcome, (2) clinical outcome, and (3) perioperative complications in patients with vertebral compression fractures treated with VBS at minimum 6-month follow-up.

METHODS

In this retrospective cohort study, 78 patients (61 ± 14 [21-90] years; 67% female) who have received a vertebral body stent due to a traumatic, osteoporotic or metastatic thoracolumbar compression fracture at our hospital between 2012 and 2020 were included. Median follow-up was 0.9 years with a minimum follow-up of 6 months. Radiographic and clinical outcome was analyzed directly, 6 weeks, 12 weeks, 6 months postoperatively, and at last follow-up.

RESULTS

Anterior vertebral body height of all patients improved significantly by mean 6.2 ± 4.8 mm directly postoperatively (p < 0.0001) and remained at 4.3 ± 5.1 mm at last follow-up compared to preoperatively (p < 0.0001). The fracture kyphosis angle of all patients improved significantly by mean 5.8 ± 6.9 degrees directly postoperatively (p < 0.0001) and remained at mean 4.9 ± 6.9 degrees at last follow-up compared to preoperatively (p < 0.0001). The segmental kyphosis angle of all patients improved significantly by mean 7.1 ± 7.6 degrees directly postoperatively (p < 0.0001) and remained at mean 2.8 ± 7.8 degrees at last follow-up compared to preoperatively (p = 0.03). Back pain was ameliorated from a preoperative median Numeric Rating Scale value of 6.5 to 3.0 directly postoperatively and further bettered to 1.0 six months postoperatively (p = 0.0001). Revision surgery was required in one patient after 0.4 years.

CONCLUSION

Vertebral body stenting is a safe and effective treatment option for osteoporotic, traumatic and metastatic compression fractures.

Biological Characteristics of Polyurethane-Based Bone-Replacement Materials

A study is presented on four polymers of the polyurethane family, obtained using a two-stage process. The first composition is the basic polymer; the others differ from it by the presence of a variety of fillers, introduced to provide radiopacity. The fillers used were 15% bismuth oxide (Composition 2), 15% tantalum pentoxide (Composition 3), or 15% zirconium oxide (Composition 4). Using a test culture of human fibroblasts enabled the level of cytotoxicity of the compositions to be determined by MTT (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide) assay, along with variations in the characteristics of the cells resulting from their culture directly on the specimens. The condition of cells on the surfaces of the specimens was assessed using fluorescence microscopy. It was shown that introducing 15% bismuth, tantalum, or zinc compounds as fillers produced a range of effects on the biological characteristics of the compositions. With the different fillers, the levels of toxicity differed and the cells' proliferative activity or adhesion was affected. However, in general, all the studied compositions may be considered cytocompatible in respect of their biological characteristics and are promising for further development as bases for bone-substituting materials. The results obtained also open up prospects for further investigations of polyurethane compounds.

Short-segment fixation and transpedicular bone grafting for the treatment of thoracolumbar spine fracture

Purpose

Thoracolumbar fracture is one of the most common fractures of spine. And short-segment posterior fixation including the fractured vertebra (SSPFI) is usually used for the surgical treatment of it. However, the outcomes of SSPFI for different types of thoracolumbar fractures are not clear, and whether it is necessary to perform transpedicular bone grafting is still controversial. This study was conducted to determine the clinical efficacy of SSPFI for the treatment of different types of single-level thoracolumbar fracture, and make clear what kind of fractures need transpedicular bone grafting during the surgery.

Methods

Patients with single-level thoracolumbar fracture undergoing SSPFI surgery between January 2013 and June 2020 were included in this study. The operative duration, intraoperative blood loss, anterior vertebral height ratio (AVHR) and anterior vertebral height compressive ratio (AVHC) of the fractured vertebra, local kyphotic Cobb angle (LKA), vertebral wedge angle (VWA) and correction loss during follow up period were recorded. Outcomes between unilateral and bilateral pedicle screw fixation for fractured vertebra, between SSPFI with and without transpedicular bone grafting (TBG), and among different compressive degrees of fractured vertebrae were compared, respectively.

Results

A total of 161 patients were included in this study. All the patients were followed up, and the mean follow-upped duration was 25.2 ± 3.1 months (6-52 months). At the final follow-up, the AVHR was greater, and the LKA and VWA were smaller in patients with bilateral fixation (6-screw fixation) than those with unilateral fixation (5-screw fixation) of AO type A3/A4 fractures (P < 0.001). The correction loss of AVHR, LKA and VWA in fractured vertebra were significantly great when preoperative AVHC was >50% (P < 0.05). For patients with AVHC >50%, the correction loss in patients with TBG were less than those without TBG at the final follow-up (P < 0.05).

Conclusions

SSPFI using bilateral fixation was more effective than unilateral fixation in maintaining the fractured vertebral height for AO type A3/A4 fractures. For patients with AVHC >50%, the loss of correction was more obvious and it can be decreased by transpedicular bone grafting.

Effect of surgical experience and spine subspecialty on the reliability of the AO Spine Upper Cervical Injury Classification System

OBJECTIVE

The objective of this paper was to determine the interobserver reliability and intraobserver reproducibility of the AO Spine Upper Cervical Injury Classification System based on surgeon experience (< 5 years, 5-10 years, 10-20 years, and > 20 years) and surgical subspecialty (orthopedic spine surgery, neurosurgery, and "other" surgery).

METHODS

A total of 11,601 assessments of upper cervical spine injuries were evaluated based on the AO Spine Upper Cervical Injury Classification System. Reliability and reproducibility scores were obtained twice, with a 3-week time interval. Descriptive statistics were utilized to examine the percentage of accurately classified injuries, and Pearson's chi-square or Fisher's exact test was used to screen for potentially relevant differences between study participants. Kappa coefficients (κ) determined the interobserver reliability and intraobserver reproducibility.

RESULTS

The intraobserver reproducibility was substantial for surgeon experience level (< 5 years: 0.74 vs 5-10 years: 0.69 vs 10-20 years: 0.69 vs > 20 years: 0.70) and surgical subspecialty (orthopedic spine: 0.71 vs neurosurgery: 0.69 vs other: 0.68). Furthermore, the interobserver reliability was substantial for all surgical experience groups on assessment 1 (< 5 years: 0.67 vs 5-10 years: 0.62 vs 10-20 years: 0.61 vs > 20 years: 0.62), and only surgeons with > 20 years of experience did not have substantial reliability on assessment 2 (< 5 years: 0.62 vs 5-10 years: 0.61 vs 10-20 years: 0.61 vs > 20 years: 0.59). Orthopedic spine surgeons and neurosurgeons had substantial intraobserver reproducibility on both assessment 1 (0.64 vs 0.63) and assessment 2 (0.62 vs 0.63), while other surgeons had moderate reliability on assessment 1 (0.43) and fair reliability on assessment 2 (0.36).

CONCLUSIONS

The international reliability and reproducibility scores for the AO Spine Upper Cervical Injury Classification System demonstrated substantial intraobserver reproducibility and interobserver reliability regardless of surgical experience and spine subspecialty. These results support the global application of this classification system.

Automated detection and classification of acute vertebral body fractures using a convolutional neural network on computed tomography

BACKGROUND

Acute vertebral fracture is usually caused by low-energy injury with osteoporosis and high-energy trauma. The AOSpine thoracolumbar spine injury classification system (AO classification) plays an important role in the diagnosis and treatment of the disease. The diagnosis and description of vertebral fractures according to the classification scheme requires a great deal of time and energy for radiologists.

PURPOSE

To design and validate a multistage deep learning system (multistage AO system) for the automatic detection, localization and classification of acute thoracolumbar vertebral body fractures according to AO classification on computed tomography.

MATERIALS AND METHODS

The CT images of 1,217 patients who came to our hospital from January 2015 to December 2019 were collected retrospectively. The fractures were marked and classified by 2 junior radiology residents according to the type A standard in the AO classification. Marked fracture sites included the upper endplate, lower endplate and posterior wall. When there were inconsistent opinions on classification labels, the final result was determined by a director radiologist. We integrated different networks into different stages of the overall framework. U-net and a graph convolutional neural network (U-GCN) are used to realize the location and classification of the thoracolumbar spine. Next, a classification network is used to detect whether the thoracolumbar spine has a fracture. In the third stage, we detect fractures in different parts of the thoracolumbar spine by using a multibranch output network and finally obtain the AO types.

RESULTS

The mean age of the patients was 61.87 years with a standard deviation of 17.04 years, consisting of 760 female patients and 457 male patients. On vertebrae level, sensitivity for fracture detection was 95.23% in test dataset, with an accuracy of 97.93% and a specificity of 98.35%. For the classification of vertebral body fractures, the balanced accuracy was 79.56%, with an AUC of 0.904 for type A1, 0.945 for type A2, 0.878 for type A3 and 0.942 for type A4.

CONCLUSION

The multistage AO system can automatically detect and classify acute vertebral body fractures in the thoracolumbar spine on CT images according to AO classification with high accuracy.

Puntajes V

El Comité Editorial quiere brindar a los lectores de la RAAOT una actualización de las escalas de uso corriente. El empleo de tablas y escalas es una práctica muy extendida en la ortopedia y traumatología. La medición y la cuantificación de los aspectos clínicos, funcionales y radiográficos se convirtieron en una herramienta imprescindible para la toma de decisiones en diferentes aspectos de la actividad asistencial. Llevamos a cabo una revisión de las escalas más utilizadas, definimos su uso e incluimos bibliografía original y actualizada.Nivel de Evidencia: V

Performance of a deep convolutional neural network for MRI-based vertebral body measurements and insufficiency fracture detection

OBJECTIVES

The aim is to validate the performance of a deep convolutional neural network (DCNN) for vertebral body measurements and insufficiency fracture detection on lumbar spine MRI.

METHODS

This retrospective analysis included 1000 vertebral bodies in 200 patients (age 75.2 ± 9.8 years) who underwent lumbar spine MRI at multiple institutions. 160/200 patients had ≥ one vertebral body insufficiency fracture, 40/200 had no fracture. The performance of the DCNN and that of two fellowship-trained musculoskeletal radiologists in vertebral body measurements (anterior/posterior height, extent of endplate concavity, vertebral angle) and evaluation for insufficiency fractures were compared. Statistics included (a) interobserver reliability metrics using intraclass correlation coefficient (ICC), kappa statistics, and Bland-Altman analysis, and (b) diagnostic performance metrics (sensitivity, specificity, accuracy). A statistically significant difference was accepted if the 95% confidence intervals did not overlap.

RESULTS

The inter-reader agreement between radiologists and the DCNN was excellent for vertebral body measurements, with ICC values of > 0.94 for anterior and posterior vertebral height and vertebral angle, and good to excellent for superior and inferior endplate concavity with ICC values of 0.79-0.85. The performance of the DCNN in fracture detection yielded a sensitivity of 0.941 (0.903-0.968), specificity of 0.969 (0.954-0.980), and accuracy of 0.962 (0.948-0.973). The diagnostic performance of the DCNN was independent of the radiological institution (accuracy 0.964 vs. 0.960), type of MRI scanner (accuracy 0.957 vs. 0.964), and magnetic field strength (accuracy 0.966 vs. 0.957).

CONCLUSIONS

A DCNN can achieve high diagnostic performance in vertebral body measurements and insufficiency fracture detection on heterogeneous lumbar spine MRI.

KEY POINTS

• A DCNN has the potential for high diagnostic performance in measuring vertebral bodies and detecting insufficiency fractures of the lumbar spine.

Thoracolumbar spine trauma: a guide for the FRCS examination

Thoracolumbar spine injuries are commonly seen in trauma settings and have a high risk of causing serious morbidity. There can be controversy when it comes to classifying thoracolumbar injuries within the spinal community, but there remains a need to classify, evaluate and manage thoracolumbar fractures. This article aims to provide a guide on classification of thoracolumbar spine injuries using the AO Spine Thoracolumbar Injury Classification System (AO TLICS).

AO Spine upper cervical injury classification system: a description and reliability study

BACKGROUND CONTEXT

Prior upper cervical spine injury classification systems have focused on injuries to the craniocervical junction (CCJ), atlas, and dens independently. However, no previous system has classified upper cervical spine injuries using a comprehensive system incorporating all injuries from the occiput to the C2-3 joint.

PURPOSE

To (1) determine the accuracy of experts at correctly classifying upper cervical spine injuries based on the recently proposed AO Spine Upper Cervical Injury Classification System (2) to determine their interobserver reliability and (3) identify the intraobserver reproducibility of the experts.

STUDY DESIGN/SETTING

International Multi-Center Survey.

PATIENT SAMPLE

A survey of international spine surgeons on 29 unique upper cervical spine injuries.

OUTCOME MEASURES

Classification accuracy, interobserver reliability, intraobserver reproducibility.

METHODS

Thirteen international AO Spine Knowledge Forum Trauma members participated in two live webinar-based classifications of 29 upper cervical spine injuries presented in random order, four weeks apart. Percent agreement with the gold-standard and kappa coefficients (ƙ) were calculated to determine the interobserver reliability and intraobserver reproducibility.

RESULTS

Raters demonstrated 80.8% and 82.7% accuracy with identification of the injury classification (combined location and type) on the first and second assessment, respectively. Injury classification intraobserver reproducibility was excellent (mean, [range] ƙ=0.82 [0.58-1.00]). Excellent interobserver reliability was found for injury location (ƙ = 0.922 and ƙ=0.912) on both assessments, while injury type was substantial (ƙ=0.689 and 0.699) on both assessments. This correlated to a substantial overall interobserver reliability (ƙ=0.729 and 0.732).

CONCLUSIONS

Early phase validation demonstrated classification of upper cervical spine injuries using the AO Spine Upper Cervical Injury Classification System to be accurate, reliable, and reproducible. Greater than 80% accuracy was detected for injury classification. The intraobserver reproducibility was excellent, while the interobserver reliability was substantial.

Accuracy of MRI (TLICS vs AOSIS) in assessment of thoracolumbar spine injuries for guiding treatment

Background

The thoracic segment represents the most common area fractured in the whole spine. Complete neurological deficits are commonly associated with thoracic injuries possibly due to a relatively small canal diameter as compared to the cervical or lumbar spine. Magnetic resonance is the gold standard of imaging, especially in patients suffering from neurological deficits as well as in soft tissue assessment mainly the disc, ligaments, and neural elements. The thoracolumbar injury classification and severity score system (TLICS) and the thoracolumbar AO Spine injury score (TLAOSIS), are two scoring systems designed to help surgeons in management plans of thoraco-lumbar injuries. The aim of our study is to compare these two main thoracolumbar injury classification systems in deciding the management strategies in thoraco-lumbar injuries. This study is a retrospective study that included 70 patients (42 males and 28 females) who suffered acute traumatic vertebral fractures. All patients underwent MRI including T1WI, T2W and STIR sequences. The MRI was viewed by two independent radiologists of 5- and 10-years’ experience and compared to surgical decisions.

Results

Out of 70 patients included in our study, the TL AOSIS matched treatment recommendation in 62 patients (88.6%), and the TLICS matched in 60 patients (85.7%). The TL AOSIS achieved sensitivity 95%, specificity 80%, while the TLICS achieved sensitivity 72.2%, specificity 100%.

Conclusion

Both TL AOSIS and TLICS have very close results in their reliability for guiding treatment strategy, yet TL AOSIS matched treatment recommendation more than TLICS, with sensitivity more than TLICS, while TLICS had more specificity.

Global Validation of the AO Spine Upper Cervical Injury Classification

STUDY DESIGN

Global cross-sectional survey.

OBJECTIVE

To determine the classification accuracy, interobserver reliability, and intraobserver reproducibility of the AO Spine Upper Cervical Injury Classification System based on an international group of AO Spine members.

SUMMARY OF BACKGROUND DATA

Previous upper cervical spine injury classifications have primarily been descriptive without incorporating a hierarchical injury progression within the classification system. Further, upper cervical spine injury classifications have focused on distinct anatomical segments within the upper cervical spine. The AO Spine Upper Cervical Injury Classification System incorporates all injuries of the upper cervical spine into a single classification system focused on a hierarchical progression from isolated bony injuries (type A) to fracture dislocations (type C).

METHODS

A total of 275 AO Spine members participated in a validation aimed at classifying 25 upper cervical spine injuries through computed tomography scans according to the AO Spine Upper Cervical Classification System. The validation occurred on two separate occasions, three weeks apart. Descriptive statistics for percent agreement with the gold-standard were calculated and the Pearson χ 2 test evaluated significance between validation groups. Kappa coefficients (κ) determined the interobserver reliability and intraobserver reproducibility.

RESULTS

The accuracy of AO Spine members to appropriately classify upper cervical spine injuries was 79.7% on assessment 1 (AS1) and 78.7% on assessment 2 (AS2). The overall intraobserver reproducibility was substantial (κ=0.70), while the overall interobserver reliability for AS1 and AS2 was substantial (κ=0.63 and κ=0.61, respectively). Injury location had higher interobserver reliability (AS1: κ = 0.85 and AS2: κ=0.83) than the injury type (AS1: κ=0.59 and AS2: 0.57) on both assessments.

CONCLUSION

The global validation of the AO Spine Upper Cervical Injury Classification System demonstrated substantial interobserver agreement and intraobserver reproducibility. These results support the universal applicability of the AO Spine Upper Cervical Injury Classification System.

LEVEL OF EVIDENCE

4.

The value of magnetic resonance imaging and computed tomography in the study of spinal disorders

Computed tomography (CT) and magnetic resonance imaging (MRI) have replaced conventional radiography in the study of many spinal conditions, it is essential to know when these techniques are indicated instead of or as complementary tests to radiography, which findings can be expected in different clinical settings, and their significance in the diagnosis of different spinal conditions. Proper use of CT and MRI in spinal disorders may facilitate diagnosis and management of spinal conditions. An adequate clinical approach, a good understanding of the pathological manifestations demonstrated by these imaging techniques and a comprehensive report based on a universally accepted nomenclature represent the indispensable tools to improve the diagnostic approach and the decision-making process in patients with spinal pain. Several guidelines are available to assist clinicians in ordering appropriate imaging techniques to achieve an accurate diagnosis and to ensure appropriate medical care that meets the efficacy and safety needs of patients. This article reviews the clinical indications of CT and MRI in different pathologic conditions affecting the spine, including congenital, traumatic, degenerative, inflammatory, infectious and tumor disorders, as well as their main imaging features. It is intended to be a pictorial guide to clinicians involved in the diagnosis and treatment of spinal disorders.

Rate and Predictors of Failure in the Conservative Management of Stable Thoracolumbar Burst Fractures: A Systematic Review and Meta-Analysis

STUDY DESIGN

Systematic review.

OBJECTIVES

Management of stable traumatic thoracolumbar burst fractures in neurologically-intact patients remains controversial. Conservative management fails in a subset of patients who require subsequent surgical fixation. The aim of this review is to (1) determine the rate of conservative management failure, and (2) analyze predictive factors at admission influencing conservative management failure.

METHODS

A systematic review adhering to PRISMA guidelines was performed. Studies with data pertaining to traumatic thoracolumbar burst fractures without posterior osteoligamentous injury (e.g. AO Type A3/A4) and/or the rate and predictive factors of conservative management failure were included. Risk of bias appraisal was performed. Pooled analysis of rates of failure was performed with qualitative analysis of predictors of conservative management failure.

RESULTS

16 articles were included in this review (11 pertaining to rate of conservative management failure, 5 pertaining to predictive risk factors). Rate of failure of conservative management from a pooled analysis of 601 patients is 9.2% (95% CI: 4.5%-13.9%). Admission factors predictive of conservative management failure include age, greater initial kyphotic angle, greater initial interpedicular distance, smaller initial residual canal size, greater Load Sharing Classification (LSC) score and greater admission Visual Analog Scale (VAS) pain scores.

CONCLUSION

A proportion (9.2%) of conservatively managed, neurologically-intact thoracolumbar burst fractures fail conservative management. Among other factors, age, kyphotic angle, residual canal area and interpedicular distance should be investigated in prospective studies to identify the subset of patients prone to failure of conservative management. Surgical management should be carefully considered in patients with the above risk factors.

Analysis of the Classification Systems for Thoracolumbar Fractures in Adults and Their Evolution and Impact on Clinical Management

Although they represent a significant chapter of traumatic pathology with a deep medical and social impact, thoracolumbar fractures have proven to be elusive in terms of a definitive classification. The ever-changing concept of the stability of a thoracolumbar injury (from Holdsworth’s two-column concept to Denis’ three-column theory), the meaningful integration of neurological deficit, and a reliable clinical usability have made reaching a universally accepted and reproductible classification almost impossible. The advent of sophisticated imaging techniques and an improved understanding of spine biomechanics led to the development of several classification systems. Each successive system has contributed significantly to the understanding of physiopathological mechanisms and better treatment management. Magerl et al. developed a comprehensive classification system based on progressive morphological damage determined by the following three fundamental forces: compression, distraction, and axial torque. Vaccaro et al. devised the thoracolumbar injury severity score based on the following three independent variables: the morphology of the injury, posterior ligamentous complex (PLC) integrity, and neurological status at the time of injury. However, there are limitations to the classification system, especially when magnetic resonance imaging yields an uncertain status of PLC. The authors review the various classification systems insisting on their practical relevance and caveats and illustrate the advantages and disadvantages of the most widely used systems with relevant cases from their practice.

Radiographic Factors for Adjacent Vertebral Fractures and Cement Loosening Following Balloon Kyphoplasty in Patients with Osteoporotic Vertebral Fractures

Introduction

Balloon kyphoplasty (BKP) is a minimally invasive surgical approach for the treatment of osteoporotic vertebral fractures (OVF). Some risks have been reported after treatment with BKP; therefore, it is necessary to determine when BKP does not work. Thus, in this study, we aim to clarify the radiographic predictors of secondary vertebral fractures and cement loosening after BKP for OVF.

Methods

This study enrolled patients with single-level OVF at the thoracolumbar junction (T11-L2) who underwent BKP for the first time between January 2011 and March 2014. The clinical outcomes were evaluated using the visual analog scale (VAS) and a modified Oswestry Disability Index (ODI) at 1 week and 1, 3, 6, and 12 months after surgery. Radiographic assessments were performed preoperatively and within 1 year after BKP using plain radiography and computed tomography.

Results

The 85 patients who met the inclusion criteria underwent BKP. The average age of participants (21 men, 64 women) was 77.8 years (range, 57-92 years). Postoperative VAS and ODI scores were all significantly better than preoperative scores. Polymethyl methacrylate (PMMA)-cement leakage was observed in 18 patients (21.2%) but was asymptomatic in all cases. Secondary vertebral fractures were detected in 20 patients (23.5%), including adjacent levels in 15 patients (17.6%) and non-adjacent levels in 5 patients (5.9%). Rostral bridging osteophyte formation was found to be significantly associated with the occurrence of adjacent vertebral fractures (odds ratio 12.746; p=0.010). PMMA-cement loosening was observed in three patients (3.5%). A high prevalence (100%) of bridging osteophytes, vacuum clefts, and spinous process fractures was observed in patients with PMMA-cement loosening. PMMA-cement loosening was found in 3 out of 10 patients with all three of these factors.

Conclusions

Rostral bridging osteophyte formation was determined to be a risk factor for both adjacent vertebral fractures and PMMA-cement loosening.

Level of Evidence: 3

Wiltse Approach Versus Conventional Transforaminal Interbody Fusion for Unstable Thoracolumbar Fracture with Intervertebral Disc Lesions

Objective

To compare the clinical results of two surgical techniques, Wiltse approach and conventional transforaminal interbody fusion, for the treatment of unstable thoracolumbar fracture associated with traumatic intervertebral disc lesion (TIDL).

Methods

A total of 76 patients with unstable thoracolumbar fracture associated with TIDL treated by posterior pedicle screw fixation and transforaminal thoracolumbar interbody fusion from June 2010 and July 2016 were reviewed retrospectively. These patients including 48 male and 28 female patients were divided into Wiltse approach transforaminal thoracolumbar interbody fusion (W‐TLIF) group (n = 38) and conventional transforaminal thoracolumbar interbody fusion (C‐TLIF) group (n = 38). Patients were followed up for about 33 months. Clinical and radiological records, kyphotic angle, fractured vertebral body height, visual analogue score (VAS), Oswestry Disability Index (ODI), complications, neurological improvement and fusion rate were compared between two groups.

Results

All patients underwent posterior surgery successfully. Blood loss, operation time and hospital stay in the W‐TLIF group was 437.84 ± 143.98 ml, 118.64 ± 20.55 min and 12.32 ± 2.87 days, respectively. While those parameters in the C‐TLIF group was 862.70 ± 300.24 ml, 141.35 ± 31.72 min and 15.51 ± 2.08 days, respectively. Average operation time and hospital stay time were significantly shorter, and blood loss was significantly less in the W‐TLIF group than in the C‐TLIF group (P < 0.05). VAS and ODI in the W‐TLIF group were significantly less than those in the C‐TLIF group at 1 week after operation and final follow‐up. The kyphotic angle and vertebral body height were improved. There was 1–2 grade improvement in patients with neurological deficit. Thirty‐three patients in the W‐TLIF group and 32 patients in the C‐TLIF group had achieved fusion during follow‐up. No internal fixation failure was observed in two groups.

Conclusions

The both techniques of W‐TLIF and C‐TLIF were feasible and effective for unstable thoracolumbar fracture with TIDL. Compare to C‐TLIF, The technique of W‐TLIF was a relatively less invasive way to decompress the neural elements and an easy method to reconstruct the anterior column using the same posterior approach.

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.

SHORT ARTHRODESIS IS AS EFFECTIVE AS LONG ARTHRODESIS FOR THE TREATMENT OF TYPE B THORACOLUMBAR SPINE FRACTURES

ABSTRACT Objective: Thoracolumbar spine trauma is a world wide health concern that especially affects males of working age, being associated with an elevated morbidity. AO SPINE Type B fractures are unstable and require surgical stabilization. However, the decision between short or long fixation remains controversial. The objective of this study is to analyze the neurological, orthopedic and functional outcomes in patients with Type B spine fractures who have undergone short and long segment posterior arthrodesis. Methods: A prospective cohort study was performed at the Neurosurgery Department of Hospital Cristo Redentor from January 1, 2013 to December 31, 2018. Patients with spine fractures classified as AO SPINE Type B in the thoracic or thoracolumbar segments were eligible for the study. The variables analyzed included demographic data, information about the trauma, neurological status, the treatment performed, and the outcome. Results: A total of 31 patients were included in the study. The majority were Caucasian males with a mean age of 42.6(±15.6), and the main cause of the spine trauma was falling from height (N=18; 56.2%). Fifteen patients (48.3%) had subtype B1 fractures and 16 (51.6%) had subtype B2 fractures. Eleven (35.4%) patients were submitted to short arthrodesis and 20 (64.5%) were submitted to long arthrodesis. There was no statistical difference between groups in terms of neurological, orthopedic and functional outcomes. Conclusions: There is no difference in outcomes between short or long constructs for patients with type B single fracture in the thoracic, thoracolumbar and lumbar spine segments. Level of evidence III; Therapeutic Studies – Investigation of treatment results.

Posterior Ligamentous Complex Injuries of the Thoracolumbar Spine: Importance and Surgical Implications

The soft tissues surrounding the spine play a primordial role in its stability, the most important of which are located posteriorly and are deemed the posterior ligamentous complex (PLC). Injuries to the PLC in the setting of thoracolumbar trauma are often dreaded and little attention has been given to them in the management protocols of thoracolumbar trauma. This review aims to summarize and contextualize current concepts in PLC injuries of the thoracolumbar spine with the aim to provide a clear guide for clinical management. Injuries to the PLC may be suspected on the clinical exam but are often missed, leading to serious complications, including instability and neurological compromise. The diagnosis is often made indirectly by spinal radiographs and CT-scanning or by direct visualization of soft tissues via magnetic resonance imaging. The latter remains the standard imaging modality and is mandatory for patients with a high suspicion of PLC injury. PLC injuries are associated with vertebral fractures and follow a progressive pattern of severity, depending on the mechanism of injury and extent of trauma. Surgical management is warranted, as PLC damage renders the spine unstable. Although fusion was once the standard of care and remains applicable for certain patients, recent endeavors of temporary spinal fixation without fusion are increasingly gaining traction in patients with PLC injuries. In conclusion, PLC injuries are challenging as they are often missed, poorly understood, and are not easily managed. Proper diagnosis and management are crucial to avoid long-standing complications such as spinal instability. Considering the paucity of available data on such an important topic in thoracolumbar trauma, this review article aims to contextualize current concepts in PLC injuries in order to demystify this sparsely covered subject.