Influência da terapia celular mononuclear sobre a degeneração discal em coelhos

ResumoObjetivoAvaliar a influência da injeção de células‐tronco mononucleares autólogas sobre as alterações histológicas do colágeno no ânulo fibroso do disco intervertebral após lesão experimental.MétodosForam submetidos 32 coelhos New Zealand a punção do discos intervertebrais lombares seguida de injeção intradiscal de células mononucleares provenientes da crista ilíaca versus injeção de solução salina nos seguintes períodos tempo: dois meses após a lesão (CT2M e SS2M), duas semanas (CT2S e SS2S), imediatamente após a lesão (CTCP e SSCP) e sem induzir a degeneração (CTSP e SSSP). Após dois meses da terapia celular, os animais foram submetidos a eutanásia e as alterações do colágeno nos discos intervertebrais foram avaliadas histologicamente.ResultadosHouve diferença estatisticamente significativa na CEAF entre os grupos CT2S e SS2S (p=0,018). Essa diferença decorreu de um aumento do colágeno do tipo I no grupo SS2S (56,7%) comparado com o CT2S (13,28%).ConclusãoO tratamento com células mononucleares precursoras mesenquimais é capaz de reduzir as alterações na distribuição do colágeno do tipo I e III no AF de discos degenerados de coelhos até duas semanas após a indução da degeneração.AbstractObjectiveThe objective of this research was to evaluate the influence of autologous mononuclear stem cells injections on histological changes of collagen in the fibrous annulus of the intervertebral disc after experimental injury.Methods32 New Zealand rabbits were submitted to intervertebral disc puncture, followed by intradiscal injection of mononuclear cells from the iliac crest versus saline injection in the following time periods: two months after the injury (SC2M and SS2M), two weeks (SC2W and SS2W) immediately after injury (SCCP and SSCP), and without inducing degeneration (SCSP and SSSP). Two months after cell therapy, the animals were euthanized and collagen changes in the intervertebral discs were histologically evaluated.ResultsThere were significant differences in ELAF between SS2W and SS2S groups (p=0.018). This difference was due to an increase in type I collagen in SS2W group (56.7%) compared to SC2S (13.28%).ConclusionTreatment with mononuclear mesenchymal stem cells reduced changes in the type I and III collagen distribution in rabbits AF degenerated discs up to two weeks after the induction of degeneration

An Assessment of the World's Contribution to Spine Trauma Care: A Bibliometric Analysis of Classifications and Surgical Management; An AO Spine Knowledge Forum Trauma Initiative.

STUDY DESIGN Bibliometric analysis. OBJECTIVES An analysis of the literature related to the assessment and management of spinal trauma was undertaken to allow the identification of top contributors, collaborations and research trends. METHODS A search to identify original articles published in English between 2011 and 2020 was done using specific keywords in the Web of Science database. After screening, the top 300 most cited articles were analyzed using Biblioshiny R software. RESULTS The highest number of contributions were from the Thomas Jefferson University, USA, University of Toronto and University of British Columbia, Canada. The top 3 most prolific authors were Vaccaro AR, Arabi B, and Oner FC. The USA and Canada were among the top contributing countries; Switzerland and Brazil had most multiple country co-authored articles. The most relevant journals were the European Spine Journal, Spine and Spine Journal. Three of the 5 most cited articles were about classification systems of fractures. The keyword analysis included clusters for different spinal regions, spinal cord injury, classification agreement and reliability studies, imaging related studies, surgical techniques and outcomes. CONCLUSIONS The study identified the most impactful authors and affiliations, and determined the journals where most impactful research is published in the field. Study also compared the productivity and collaborations across countries. The study highlighted the impact of development of new classification systems, and identified research trends including instrumentation, fixation and decompression techniques, epidemiology and recovery after spinal trauma

Evolution of the AO Spine Sacral and Pelvic Classification System: a systematic review.

OBJECTIVE The purpose of this study was to describe the genesis of the AO Spine Sacral and Pelvic Classification System in the context of historical sacral and pelvic grading systems. METHODS A systematic search of MEDLINE, EMBASE, Google Scholar, and Cochrane databases was performed consistent with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines to identify all existing sacral and pelvic fracture classification systems. RESULTS A total of 49 articles were included in this review, comprising 23 pelvic classification systems and 17 sacral grading schemes. The AO Spine Sacral and Pelvic Classification System represents both the evolutionary product of these historical systems and a reinvention of classic concepts in 5 ways. First, the classification introduces fracture types in a graduated order of biomechanical stability while also taking into consideration the neurological status of patients. Second, the traditional belief that Denis central zone III fractures have the highest rate of neurological deficit is not supported because this subgroup often includes a broad spectrum of injuries ranging from a benign sagittally oriented undisplaced fracture to an unstable "U-type" fracture. Third, the 1990 Isler lumbosacral system is adopted in its original format to divide injuries based on their likelihood of affecting posterior pelvic or spinopelvic stability. Fourth, new discrete fracture subtypes are introduced and the importance of bilateral injuries is acknowledged. Last, this is the first integrated sacral and pelvic classification to date. CONCLUSIONS The AO Spine Sacral and Pelvic Classification is a universally applicable system that redefines and reorders historical fracture morphologies into a rational hierarchy. This is the first classification to simultaneously address the biomechanical stability of the posterior pelvic complex and spinopelvic stability, while also taking into consideration neurological status. Further high-quality controlled trials are required prior to the inclusion of this novel classification within a validated scoring system to guide the management of sacral and pelvic injuries

An international validation of the AO spine subaxial injury classification system.

PURPOSE To validate the AO Spine Subaxial Injury Classification System with participants of various experience levels, subspecialties, and geographic regions. METHODS A live webinar was organized in 2020 for validation of the AO Spine Subaxial Injury Classification System. The validation consisted of 41 unique subaxial cervical spine injuries with associated computed tomography scans and key images. Intraobserver reproducibility and interobserver reliability of the AO Spine Subaxial Injury Classification System were calculated for injury morphology, injury subtype, and facet injury. The reliability and reproducibility of the classification system were categorized as slight (ƙ = 0-0.20), fair (ƙ = 0.21-0.40), moderate (ƙ = 0.41-0.60), substantial (ƙ = 0.61-0.80), or excellent (ƙ = > 0.80) as determined by the Landis and Koch classification. RESULTS A total of 203 AO Spine members participated in the AO Spine Subaxial Injury Classification System validation. The percent of participants accurately classifying each injury was over 90% for fracture morphology and fracture subtype on both assessments. The interobserver reliability for fracture morphology was excellent (ƙ = 0.87), while fracture subtype (ƙ = 0.80) and facet injury were substantial (ƙ = 0.74). The intraobserver reproducibility for fracture morphology and subtype were excellent (ƙ = 0.85, 0.88, respectively), while reproducibility for facet injuries was substantial (ƙ = 0.76). CONCLUSION The AO Spine Subaxial Injury Classification System demonstrated excellent interobserver reliability and intraobserver reproducibility for fracture morphology, substantial reliability and reproducibility for facet injuries, and excellent reproducibility with substantial reliability for injury subtype

Development of Online Technique for International Validation of the AO Spine Subaxial Injury Classification System.

STUDY DESIGN Global cross-sectional survey. OBJECTIVE To develop and refine the techniques for web-based international validation of fracture classification systems. METHODS A live webinar was organized in 2018 for validation of the AO Spine Subaxial Injury Classification System, consisting of 35 unique computed tomography (CT) scans and key images with subaxial spine injuries. Interobserver reliability and intraobserver reproducibility was calculated for injury morphology, subtype, and facet injury according to the classification system. Based on the experiences from this webinar and incorporating rater feedback, adjustments were made in the organization and techniques used and in 2020 a repeat validation webinar was performed, evaluating images of 41 unique subaxial spine injuries. RESULTS In the 2018 session, the AO Spine Subaxial Injury Classification System demonstrated fair interobserver reliability for fracture subtype (κ = 0.35) and moderate reliability for fracture morphology and facet injury (κ=0.45, 0.43, respectively). However, in 2020, the interobserver reliability for fracture morphology (κ = 0.87) and fracture subtype (κ = 0.80) was excellent, while facet injury was substantial (κ = 0.74). Intraobserver reproducibility for injury morphology (κ =0.49) and injury subtype/facet injury were moderate (κ = 0.42) in 2018. In 2020, fracture morphology and subtype reproducibility were excellent (κ =0.85, 0.88, respectively) while reproducibility for facet injuries was substantial (κ = 0.76). CONCLUSION With optimized webinar-based validation techniques, the AO Spine Subaxial Injury Classification System demonstrated vast improvements in intraobserver reproducibility and interobserver reliability. Stringent fracture classification methodology is integral in obtaining accurate classification results

The Influence of Regional Differences on the Reliability of the AO Spine Sacral Injury Classification System.

STUDY DESIGN Global cross-sectional survey. OBJECTIVE To explore the influence of geographic region on the AO Spine Sacral Classification System. METHODS A total of 158 AO Spine and AO Trauma members from 6 AO world regions (Africa, Asia, Europe, Latin and South America, Middle East, and North America) participated in a live webinar to assess the reliability, reproducibility, and accuracy of classifying sacral fractures using the AO Spine Sacral Classification System. This evaluation was performed with 26 cases presented in randomized order on 2 occasions 3 weeks apart. RESULTS A total of 8320 case assessments were performed. All regions demonstrated excellent intraobserver reproducibility for fracture morphology. Respondents from Europe (k = .80) and North America (k = .86) achieved excellent reproducibility for fracture subtype while respondents from all other regions displayed substantial reproducibility. All regions demonstrated at minimum substantial interobserver reliability for fracture morphology and subtype. Each region demonstrated >90% accuracy in classifying fracture morphology and >80% accuracy in fracture subtype compared to the gold standard. Type C morphology (p2 = .0000) and A3 (p1 = .0280), B2 (p1 = .0015), C0 (p1 = .0085), and C2 (p1 =.0016, p2 =.0000) subtypes showed significant regional disparity in classification accuracy (p1 = Assessment 1, p2 = Assessment 2). Respondents from Asia (except in A3) and the combined group of North, Latin, and South America had accuracy percentages below the combined mean, whereas respondents from Europe consistently scored above the mean. CONCLUSIONS In a global validation study of the AO Spine Sacral Classification System, substantial reliability of both fracture morphology and subtype classification was found across all geographic regions

Management of Acute Traumatic Central Cord Syndrome: A Narrative Review.

Study Design Narrative review. Objectives To provide an updated overview of the management of acute traumatic central cord syndrome (ATCCS). Methods A comprehensive narrative review of the literature was done to identify evidence-based treatment strategies for patients diagnosed with ATCCS. Results ATCCS is the most commonly encountered subtype of incomplete spinal cord injury and is characterized by worse sensory and motor function in the upper extremities compared with the lower extremities. It is most commonly seen in the setting of trauma such as motor vehicles or falls in elderly patients. The operative management of this injury has been historically variable as it can be seen in the setting of mechanical instability or preexisting cervical stenosis alone. While each patient should be evaluated on an individual basis, based on the current literature, the authors' preferred treatment is to perform early decompression and stabilization in patients that have any instability or significant neurologic deficit. Surgical intervention, in the appropriate patient, is associated with an earlier improvement in neurologic status, shorter hospital stay, and shorter intensive care unit stay. Conclusions While there is limited evidence regarding management of ATCCS, in the presence of mechanical instability or ongoing cord compression, surgical management is the treatment of choice. Further research needs to be conducted regarding treatment strategies and patient outcomes

Establishing the Injury Severity of Subaxial Cervical Spine Trauma: Validating the Hierarchical Nature of the AO Spine Subaxial Cervical Spine Injury Classification System.

STUDY DESIGN Global cross-sectional survey. OBJECTIVE To validate the AO Spine Subaxial Cervical Spine Injury Classification by examining the perceived injury severity by surgeon across AO geographical regions and practice experience. SUMMARY OF BACKGROUND DATA Previous subaxial cervical spine injury classifications have been limited by subpar interobserver reliability and clinical applicability. In an attempt to create a universally validated scheme with prognostic value, AO Spine established a subaxial cervical spine injury classification involving four elements: (1) injury morphology, (2) facet injury involvement, (3) neurologic status, and (4) case-specific modifiers. METHODS A survey was sent to 272 AO Spine members across all geographic regions and with a variety of practice experience. Respondents graded the severity of each variable of the classification system on a scale from zero (low severity) to 100 (high severity). Primary outcome was to assess differences in perceived injury severity for each injury type over geographic regions and level of practice experience. RESULTS A total of 189 responses were received. Overall, the classification system exhibited a hierarchical progression in subtype injury severity scores. Only three subtypes showed a significant difference in injury severity score among geographic regions: F3 (floating lateral mass fracture, p:0.04), N3 (incomplete spinal cord injury, p:0.03), and M2 (critical disk herniation, p:0.04). When stratified by surgeon experience, pairwise comparison showed only 2 morphological subtypes, B1 (bony posterior tension band injury, p:0.02) and F2 (unstable facet fracture, p:0.03), and one neurologic subtype (N3, p:0.02) exhibited a significant difference in injury severity score. CONCLUSIONS The AO Spine Subaxial Cervical Spine Injury Classification System has shown to be reliable and suitable for proper patient management. The study shows this classification is substantially generalizable by geographic region and surgeon experience; and provides a consistent method of communication among physicians while covering the majority of subaxial cervical spine traumatic injuries.Level of Evidence: 4

The AO spine upper cervical injury classification system: Do work setting or trauma center affiliation affect classification accuracy or reliability?

PURPOSE To assess the accuracy and reliability of the AO Spine Upper Cervical Injury Classification System based on a surgeons' work setting and trauma center affiliation. METHODS A total of 275 AO Spine members participated in a validation of 25 upper cervical spine injuries, which were evaluated by computed tomography (CT) scans. Each participant was grouped based on their work setting (academic, hospital-employed, or private practice) and their trauma center affiliation (Level I, Level II or III, and Level IV or no trauma center). The classification accuracy was calculated as percent of correct classifications, while interobserver reliability, and intraobserver reproducibility were evaluated based on Fleiss' Kappa coefficient. RESULTS The overall classification accuracy for surgeons affiliated with a level I trauma center was significantly greater than participants affiliated with a level II/III center or a level IV/no trauma center on assessment one (p1<0.0001) and two (p2 = 0.0003). On both assessments, surgeons affiliated with a level I or a level II/III trauma center were significantly more accurate at identifying IIIB injury types (p1 = 0.0007; p2 = 0.0064). Academic surgeons and hospital employed surgeons were significantly more likely to correctly classify type IIIB injuries on assessment one (p1 = 0.0146) and two (p2 = 0.0015). When evaluating classification reliability, the largest differences between work settings and trauma center affiliations was identified in type IIIB injuries. CONCLUSION Type B injuries are the most difficult injury type to correctly classify. They are classified with greater reliability and classification accuracy when evaluated by academic surgeons, hospital-employed surgeons, and surgeons associated with higher-level trauma centers (I or II/III)