Development and Validation of the 17-Point Brazilian Portuguese Translated Version of the Modified Japanese Orthopedic Association Score (mJOA-BR17).

BACKGROUND: Cervical spondylotic myelopathy (CSM) is the most common degenerative dysfunction of the spinal cord in the cervical spine in patients older than 55 years. The Japanese Orthopedic Association developed a scoring system to quantify clinical impairment of CSM patients, allocate them according to the degree of impairment, and suggest best timing for surgery. The original version evaluates the upper limb motor function through the ability of feeding with chopsticks, which are not intrinsic in western populations. To compare severity and treatment improvement of any diseases, it is preferable to have modified and translated versions of questionnaires and scores closest to the original ones. The authors present a prospective cohort study to validate the 17-point Brazilian Portuguese translated version of the modified Japanese Orthopedic Association (mJOA-BR17) survey. METHODS: Patients with CSM (n = 36) were allocated to the disease group, while age- and sex-matched healthy volunteers (n = 34) were recruited for the control group. Comparison of statistical analysis of mJOA-BR17 domains for each group was established. After the translation and adaptation of mJOA-BR17, the validation was made through application to the 2 groups. RESULTS: There were statistical differences between groups in total mJOA-BR17 score (CSM, 14.14 ± 2.92; control, 16.68 ± 0.59: P < 0.001), lower limbs motor function (CSM, 3.25 ± 1.02; control, 3.91 ± 0.29: P < 0.001), upper limbs sensory function (CSM, 1.17 ± 0.81; control, 1.86 ± 0.36: P < 0.001), lower limbs sensory function (CSM, 1.62 ± 0.64; control, 2.0 ± 0.0: P < 0.001), and bladder function (CSM, 2.69 ± 0.52; control, 2.97 ± 0.17: P = 0.005). The receiver operating characteristic curve was 0.81, indicating usefulness of the mJOA-BR17 score to identify patients with CSM from healthy controls. CONCLUSIONS: The mJOA-BR17 demonstrated similarity, applicability, and good understanding in comparison to the English-modified version of 17-point JOA score for CSM, becoming a valuable tool to quantify and differentiate CSM patients from healthy individuals.

The proximally designed sural flap based on the accompanying artery of the lesser saphenous vein.

Most of the literature about the sural flap deals with soft tissue defects at the lower leg and foot based on the classical description of Masquelet et al. Nevertheless, some authors have shown that the lesser saphenous vein and its accompanying artery play an important role in the vascularization of the posterior skin of the leg. This finding allowed a more proximal design of the flap, increasing its arc of rotation. Thirteen cases of distally based sural flaps were performed and divided in two groups according to the level where the flaps were harvested. In group A, the entire flap was outlined distal to the midpoint of the leg, and in group B, the flap was outlined proximal to the midpoint of the leg. In group A, all the soft tissue defects were located at the lower leg and the foot, and in group B, they involved the anterior the tibia. In group A, the complication rate was 33.33% and the flap survival rate was 83.33%. In group B, the complication rate was 42.85% and survival rate was 100%. The proximally designed sural flap can safely reach the anterior aspect of the tibia in its middle and distal thirds.

Photopolymerizable biogel scaffold seeded with mesenchymal stem cells: safety and efficacy evaluation of novel treatment for intervertebral disc degeneration.

Tissue engineering approaches to treatment of intervertebral disc degeneration (IDD) represent a novel avenue of addressing the biologic basis of this disease. However, such approaches remain limited by their invasive nature and disruption to the annular fibrosis (AF). This study sought to explore a new minimally-invasive tissue-engineering approach utilizing an injection of a photopolymerizable biogel scaffold seeded with mesenchymal stem cells (MSCs) directly into the nucleus pulposus (NP). This study was performed using rabbit specimens for both in vivo and in vitro outcome measures. The treatment in this study was performed by injecting 25 µl of 10% (w/v) methacrylated gelatin biogel with 0.15% (w/v) lithium phenyl 2,4,6-trimethylbenzoylphosphinate (LAP) and rabbit MSCs (1 × 106 ) cells/ml into the NP. Samples were then photopolymerized in situ using non-ultraviolet light irradiation via a fiberoptic wire. For the in vitro arm of this study, gene expression analysis demonstrated increased anabolic activity in irradiated MSCs with and without biogel scaffolds. For the in vivo arm of this study, while GAG analysis did not demonstrate significant differences between groups, MRI analysis exhibited a trend toward improved NP matrix. Histological analysis was consistent with increased cellularity and less severe disc degeneration in the MSC + Gel group. However, osteophyte formation was noted in both Stab and MSC + Gel groups after the study period. Increased matrix gene expression of irradiated groups within in vitro studies indicates a photobiologic effect of 405 nm light. Despite promising anabolic actions, osteophyte formation and AF defects could not be avoided with implementation of this minimally-invasive tissue-engineering approach. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 37:1451-1459, 2019.

NSAID use in intervertebral disc degeneration: what are the effects on matrix homeostasis in vivo?

BACKGROUND CONTEXT: Non-steroidal anti-inflammatory drugs (NSAIDs) are a widely used treatment for low back pain (LBP). Literature on NSAID use in articular cartilage has shown detrimental effects; however, minimal data exist to detail the effects of NSAIDs in intervertebral disc degeneration (IDD). As IDD is a major cause of LBP, we explored the effects of indomethacin, a commonly used NSAID, on disc matrix homeostasis in an animal model of IDD. PURPOSE: This study aimed to determine the effects of oral indomethacin administration on IDD in an in vivo rabbit model. This study hypothesized that indomethacin use would accelerate the progression of IDD based upon serial imaging and tissue outcomes. STUDY DESIGN/SETTING: This was a laboratory-based, controlled, in vivo evaluation of the effects of oral indomethacin administration on rabbit intervertebral discs. METHODS: Six skeletally mature New Zealand white rabbits were divided into two groups: disc puncture alone to induce IDD (Puncture group) and disc puncture plus indomethacin (Punc+Ind group). The Punc+Ind group received daily administration of 6mg/kg oral indomethacin. Serial magnetic resonance imaging (MRI) was obtained at 0, 4, 8, and 12 weeks. The MRI index and the nucleus pulposus (NP) area were calculated. Discs were harvested at 12 weeks for determination of disc glycosaminoglycan (GAG) content, relative gene expression measured by real-time polymerase chain reaction, and histologic analyses. RESULTS: The MRI index and the NP area of punctured discs in the Punc+Ind group demonstrated no worsening of degeneration compared with the Puncture group. Histologic analysis was consistent with less severe disc degeneration in the Punc+Ind group. Minimal differences in gene expression of matrix genes were observed between Puncture and Punc+Ind groups. The GAG content was higher in animals receiving indomethacin in both annulus fibrosus and NP at adjacent uninjured discs. CONCLUSIONS: Oral indomethacin administration did not result in acceleration of IDD in an in vivo rabbit model. Future research is needed to ascertain long-term effects of indomethacin and other NSAIDs on disc matrix homeostasis.

ADAMTS5 Deficiency Protects Mice From Chronic Tobacco Smoking-induced Intervertebral Disc Degeneration.

STUDY DESIGN: ADAMTS5-deficient and wild type (WT) mice were chronically exposed to tobacco smoke to investigate effects on intervertebral disc degeneration (IDD). OBJECTIVE: The aim of this study was to demonstrate a role for ADAMTS5 in mediating tobacco smoking-induced IDD. SUMMARY OF BACKGROUND DATA: We previously demonstrated that chronic tobacco smoking causes IDD in mice because, in part, of proteolytic destruction of disc aggrecan. However, it was unknown which matrix proteinase(s) drive these detrimental effects. METHODS: Three-month-old WT (C57BL/6) and ADAMTS5 mice were chronically exposed to tobacco smoke (four cigarettes/day, 5 day/week for 6 months). ADAMTS-mediated cleavage of disc aggrecan was analyzed by Western blot. Disc total glycosaminoglycan (GAG) content was assessed by dimethyl methylene blue assay and safranin O/fast green histology. Vertebral osteoporosity was measured by microcomputed tomography. Human nucleus pulposus (hNP) cell cultures were also exposed directly to tobacco smoke extract (TSE), a condensate containing the water-soluble compounds inhaled by smokers, to measure ADAMTS5 expression and ADAMTS-mediated cleavage of aggrecan. Activation of nuclear factor (NF)-κB, a family of transcription factors essential for modulating the cellular response to stress, was measured by immunofluorescence assay. RESULTS: Genetic depletion of ADAMTS5 prevented vertebral bone loss, substantially reduced loss of disc GAG content, and completely obviated ADAMTS-mediated proteolysis of disc aggrecan within its interglobular domain (IGD) in mice following exposure to tobacco smoke. hNP cell cultures exposed to TSE also resulted in upregulation of ADAMTS5 protein expression and a concomitant increase in ADAMTS-mediated cleavage within aggrecan IGD. Activation of NF-κB, known to be required for ADAMTS5 gene expression, was observed in both TSE-treated hNP cell cultures and disc tissue of tobacco smoke-exposed mice. CONCLUSION: The findings demonstrate that ADAMTS5 is the primary aggrecanase mediating smoking-induced disc aggrecanolysis and IDD. Mouse models of chronic tobacco smoking are important and useful for probing the mechanisms of disc aggrecan catabolism and IDD. LEVEL OF EVIDENCE: N/A.

Lumbar arthrodesis in degenerative spine: post operative results and radiographic evaluation / Artrodese lombar nas afecções degenerativas da coluna: análise radiográfica e resultados pós-operatórios / Lumbar arthrodesis in degenerative spine: post operative results and radiographic evaluation

ABSTRACT Objective: To relate the radiographic fusion rate and the surgical results in patients undergoing posterolateral arthrodesis with instrumentation of the lumbar spine for the treatment of degenerative disorders. Method: A descriptive, retrospective, case series, observational study, based on medical records and imaging studies of 76 patients over 18 years of age (39 to 88 years) who underwent posterolateral lumbar arthrodesis. Data related to the presence of comorbidities were compiled and clinical outcomes were measured using specific questionnaires collected pre-surgical and 1 year after surgery. Fusion quality, as described by Christensen, was assessed from radiographic images by two examiners. The VAS, EQ-5D and Roland Morris questionnaires were used preoperatively and 1 year after surgery to assess pain, quality of life and function, respectively. Result: It was observed improvement in pain, function and quality of life after 1 year post-surgical. Pain, measured by VAS, had a reduction from 7.92 to 3.16 (p-value <0.001), the function evaluated by the Roland Morris score, also showed a reduction from 14.90 to 7.06 (p-value <0.001) . Culminating with the improvement in quality of life, measured by the EQ-5D, where there was a median increase in the score from 0.5672 to 0.7002 (p-value = 0.002). Conclusion: The absence of radiographic fusion has no direct correlation with worse results in clinical outcomes at 01 year after surgery. Most patients showed clinical improvement with no statistical difference in relation to cases in which bone fusion was obtained. Level of evidence IV; retrospective observation.

RESUMO: Objetivo: Relacionar a taxa de fusão radiográfica e os resultados cirúrgicos nos pacientes submetidos a artrodese posterolateral com instrumentação da coluna lombar para tratamento de afecções degenerativas. Método: Estudo observacional retrospectivo descritivo, tipo série de casos, com base em prontuários médicos e exames de imagem de 76 pacientes maiores de 18 anos (39 a 88 anos), submetidos a artrodese lombar posterolateral. Dados relacionados a presença de comorbidades foram compilados e os desfechos clínicos mensurados por meio de questionários específicos coletados no pré-cirúrgico e após um ano pós-cirúrgico. A qualidade da fusão, conforme descrita por Christensen, foi avaliada a partir de imagens radiográficas por dois examinadores. Os questionários de EVA, EQ-5D e Roland Morris foram utilizados no pré-cirúrgico e um ano pós-cirúrgico para avaliar dor, qualidade de vida e função, respectivamente. Resultado: Observou se melhora na dor, função e qualidade de vida após um ano pós-cirúrgico. A dor, mensurada pelo EVA teve uma redução de 7,92 para 3,16 (p-valor <0,001), a função avaliada pelo escore Roland Morris, também apresentou redução de 14,90 para 7,06 (p-valor <0,001). Culminando com a melhora na qualidade de vida, mensurada pelo EQ-5D, onde observou-se um aumento mediano escore de 0,5672 para 0,7002 (p-valor = 0,002). Conclusão: A ausência de fusão radiográfica não tem correlação direta com piores resultados nos desfechos clínicos em um ano de pós-cirúrgico. Maioritariamente, os pacientes apresentaram melhora clínica sem diferença estatística em relação aos casos em que foi obtido fusão óssea. Nível de evidência IV; Observacional retrospectivo.

RESUMEN: Objetivo: Relacionar ei índice de fusión radiográfica y los resultados quirúrgicos en pacientes sometidos a artrodesis posterolateral con instrumentación de columna lumbar para el tratamiento de trastornos degenerativos. Método: Estudio descriptivo, retrospectivo, serie de casos, observacional, basado en historias clínicas y estudios de imagen de 76 pacientes may ores de 18 anos (39 a 88 anos) a quienes se les realizó artrodesis lumbar posterolateral. Se recopilaron datos relacionados con la presencia de comorbilidades y se midieron los resultados clínicos mediante cuestionarios específicos recogidos antes de la cirugía y al año de la cirugía. La calidad de la fusión, según lo descrito por Christensen, fue evaluada a partir de imágenes radiográficas por dos examinadores. Los cuestionarios VAS, EQ-5D y Roland Morris se utilizaron en el preoperatorio y 1 año después de la cirugía para evaluar el dolor, la calidad de vida y la función, respectivamente. Resultado: Se observó mejoría en el dolor, función y calidad de vida después de 1 año posquirúrgico. El dolor, medido por EVA, tuvo una reducción de 7,92 a 3,16 (p-valor <0,001), la función evaluada por el puntaje de Roland Morris, también mostró una reducción de 14,90 a 7,06 (p-valor <0,001). Culminando con la mejora en la calidad de vida, medida por el EQ-5D, donde hubo un aumento mediano en el puntaje de 0,5672 a 0,7002 (p-valor = 0,002). Conclusión: La ausencia de fusión radiográfica no tiene correlación directa con peores resultados en los resultados clínicos al 01 año de la cirugía. La mayoría de los pacientes presentaron mejoría clínica sin diferencia estadística en relación a los casos en los que se obtuvo fusión ósea. Nivel de evidencia IV; observación retrospectiva.

Reliability of the goutallier classification system in the evaluation of the multifidus muscle / Concordância da classificação de goutallier na avaliação do músculo multífido / Fiabilidad del sistema de clasificación de goutallier en la evaluación del músculo multífido

ABSTRACT Introduction: The paravertebral musculature is essential for the biomechanics and stability of the spine, and its involvement in the pathophysiology of spinal diseases has been demonstrated. Qualitative evaluation of muscle degeneration is usually performed by analyzing the fat infiltration rate proposed by the Goutallier classification system. Objective: The objective of this study is to analyze the intra- and interobserver agreement of the Goutallier Classification for the evaluation of fatty degeneration of the multifidus muscle, using magnetic resonance imaging exams. Methods: The study included 68 patients, all diagnosed with symptomatic disc hernia and indicated for surgery. Preoperative magnetic resonance images were used for the analyses. The images were initially evaluated by two orthopedists and two medical students, and then re-evaluated after two weeks. Intra- and inter-observer reliability analysis was performed using the Fleiss Kappa test and the Landis and Koch criteria. All the analyses were performed using the R statistical environment (R Development Core Team, version 3.3.1, 2016) and the significance level was set at 5%. Results: The percentages of intra- and inter-observer agreement were 86.76% and 61.03%, respectively. The intraobserver agreement was near perfect and the interobserver agreement was moderate. Conclusion: The Goutallier Classification System showed moderate interobserver and intraobserver agreement, being a relevant tool for the evaluation of paravertebral musculature fat replacement. Level of evidence II; Prospective study for diagnostic purposes.

RESUMO Introdução: A musculatura paravertebral é essencial para a biomecânica e estabilidade da coluna e tem sido demonstrado seu envolvimento na fisiopatologia das doenças da coluna vertebral. A avaliação qualitativa da degeneração muscular é usualmente feita pela análise da taxa de infiltração de gordura proposta pelo Sistema de Classificação de Goutallier. Objetivo: O objetivo deste trabalho é analisar a concordância intra e interobservador da Classificação de Goutallier para avaliação da degeneração gordurosa do músculo multífido por meio de exames de ressonância magnética. Métodos: Fizeram parte do estudo 68 pacientes, todos com diagnóstico de hérnia discal sintomática e com indicação cirúrgica. As imagens de ressonância magnética colhidas no pré-operatório foram analisadas por dois ortopedistas e dois estudantes de medicina e foram reavaliadas duas semanas depois. Foi realizada análise de confiabilidade intra e interobservador por meio do teste Kappa de Fleiss e pelos critérios de Landis e Koch. Todas as análises foram realizadas com o auxílio do ambiente estatístico R (R Development Core Team, versão 3.3.1, 2016), e o nível de significância foi fixado em 5%. Resultados: As porcentagens de concordância intra e interobservadores foram, respectivamente, 86,76% e 61,03%. A concordância intraobservador foi quase perfeita e moderada interobservadores. Conclusões: O Sistema de Classificação de Goutallier demonstrou concordância moderada interobservador e intraobservador, sendo uma ferramenta relevante na avaliação da substituição gordurosa da musculatura paravertebral. Nível de evidência II; Estudo prospectivo para fins diagnósticos.

RESUMEN Introducción: La musculatura paravertebral es fundamental para la biomecánica y la estabilidad de la columna y se ha demostrado su intervención en la fisiopatología de las enfermedades de la columna. La evaluación cualitativa de la degeneración muscular se suele realizar analizando la tasa de infiltración de grasa propuesta por el sistema de clasificación de Goutallier. Objetivo: El objetivo de este estudio es analizar la concordancia intra e interobservador de la Clasificación de Goutallier para evaluar la degeneración grasa del músculo multífido mediante resonancia magnética. Métodos: Formaron parte del estudio 68 pacientes, todos con diagnóstico de hernia discal sintomática y con indicación quirúrgica. Se utilizaron imágenes de resonancia magnética preoperatorias para el análisis. Las imágenes fueron evaluadas inicialmente por 02 ortopedistas y 02 estudiantes de medicina y, después de dos semanas, reevaluadas. El análisis de fiabilidad intra e interobservador se realizó mediante la prueba Kappa de Fleiss y los criterios de Landis y Koch. Todos los análisis se realizaron utilizando el entorno estadístico R (R Development Core Team, 2016), versión 3.3.1, y el nivel de significancia se estableció en 5%. Resultados: Los porcentajes de concordancia intra e interobservador fueron, respectivamente, 86,76% y 61,03%. La concordancia intraobservador fue casi perfecta y la concordancia interobservador fue moderada. Conclusión: el Sistema de Clasificación de Goutallier demostró una moderada concordancia interobservador e intraobservador, siendo una herramienta relevante en la evaluación del reemplazo graso de la musculatura paravertebral. Nivel de evidencia II; Estudio prospectivo con fines diagnósticos.

Catabolic effects of endothelial cell-derived microparticles on disc cells: Implications in intervertebral disc neovascularization and degeneration.

Neovascularization of intervertebral discs, a phenomenon considered pathological since normal discs are primarily avascular structures, occurs most frequently in annulus fibrosus (AF) of degenerated discs. Endothelial cells (ECs) are involved in this process, but the mechanism of the interaction between AF and endothelial cells is unclear. In this study, we evaluated the effects on matrix catabolic activity of AF cells by the extracellular endothelial microparticles (EMPs) and soluble protein factors (SUP fraction) produced from ECs. Passage 1 human AF cells grown in monolayer cultures were treated for 72 h with 250 µg of EMPs or SUP fraction isolated from culture of the microvascular endothelial cell line, HEMC-I. Live-cell imaging revealed uptake of EMPs by AF cells. RT-PCR analysis demonstrated increased mRNA expression of MMP-1 (50.3-fold), MMP-3 (4.5-fold) and MMP-13 (5.5-fold) in AF cell cultures treated with EMPs compared to untreated control. Western analysis also demonstrated increased MMP protein expression in EMP-treated AF cells. AF cells treated with the SUP fraction also exhibited a dramatic increase in MMP mRNA and protein expression. Increased MMP expression is primarily due to EMP or SUP stimulation of AF cells since EMPs or SUP fraction alone contained negligible amount of MMPs. Interestingly, MMP activity was elevated in AF cell cultures treated with EMPs but not with SUP. This study revealed enhanced matrix catabolism as a molecular consequence of action of ECs on AF cells via EMPs, which might be expected during neo-angiogenesis of degenerating disc. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:1466-1474, 2016.

Histological analysis of the repair of dural lesions with silicone mesh in rats subjected to experimental lesions.

OBJECTIVE: To evaluate inflammatory reaction, fibrosis and neovascularization in dural repairs in Wistar rats using four techniques: simple suture, bovine collagen membrane, silicon mesh and silicon mesh with suture. METHODS: Thirty Wistar rats were randomized in five groups: the first was the control group, submitted to dural tear only. The others underwent durotomy and simple suture, bovine collagen membrane, silicon mesh and silicon mesh with suture. Animals were euthanized and the spine was submitted to histological evaluation with a score system (ranging from zero to 3) for inflammation, neovascularization and fibrosis. RESULTS: Fibrosis was significantly different between simple suture and silicon mesh (p=0.005) and between simple suture and mesh with suture (p=0.015), showing that fibrosis is more intense when a foreign body is used in the repair. Bovine membrane was significantly different from mesh plus suture (p=0.011) regarding vascularization. Inflammation was significantly different between simple suture and bovine collagen membrane. CONCLUSION: Silicon mesh, compared to other commercial products available, is a possible alternative for dural repair. More studies are necessary to confirm these findings.

Bone tissue repair in patients with open diaphyseal tibial fracture treated with biplanar external fixation or reamed locked intramedullary nailing.

INTRODUCTION: Open tibial fractures are usually caused by high-energy trauma. There is no consensus about the best treatment for these fractures. Biomechanical studies show that fixing on two planes approaches the rigidity of the bone, whereas the use of interlocking intramedullary nailing is widely used and reported to produce better therapeutic results in fracture healing. OBJECTIVE: To compare bone tissue repair in patients with open diaphyseal tibial fracture treated with biplanar external fixation or reamed locked intramedullary nailing. METHOD: Prospective randomised study with 68 patients undergoing two types of surgical treatment: biplanar external fixation or reamed locked intramedullary nailing. Consolidation, complications (infection, malunion and non-union) and quality of life using the SF-36 Health Survey were assessed 12 months after surgery. RESULTS: Consolidation occurred in 84.6% of patients who underwent reamed intramedullary nailing, and in 90.3% of patients who were treated with biplanar external fixation. In the intramedullary nailing group, there were two cases of non-union, three cases of malunion and two cases of infection. In the patients treated with biplanar fixation, there were three cases of non-union, five cases of malunion and no cases of infection. There were no statistically significant differences between the treatment groups for these results. Patient quality of life was statistically equal for both methods. CONCLUSION: Treatment with biplanar external fixation was associated with statistically similar results compared with intramedullary locking.

Traumatic L5-S1 spondylolisthesis in a 15-year-old: a case report.

Traumatic spondylolisthesis is a rare injury resulting from complex trauma and high-energy mechanisms. We present a case report of traumatic spondylolisthesis at the L5-S1 disc space of a patient who was buried after a wall fell on his back. In the physical examination, bilaterally decreased muscle strength was observed. Examination images indicated a 90% slip at L5-S1. Surgical treatment was provided with a posterior and anterior approach using pedicle fixation and an anterior cage. After 4 months, there was significant recovery of muscle strength in the lower limbs.

Expression of matrix factors in the process of neovascularization of intervertebral disc / Expressão de fatores da matriz durante o processo de neovascularização do disco intervertebral / Expresión de factores de la matriz en el proceso de neovascularización del disco intervertebral

To investigate the effects of proteins products of endothelial cells (ECs) on the annulus fibrosus (AF) cell metabolism in an in vitro culture.

Analisar o efeito de produtos proteicos de células endoteliais (CEs) sobre o metabolismo de células de ânulo fibroso (AF) em ambiente controlado de cultura celular in vitro.

Analizar el efecto de los productos de proteína de las células endoteliales (CEs) en el metabolismo celular del anillo fibroso (AF) en sistema in vitro de cultivo controlado.

Histological analysis of the repair of dural lesions with silicone mesh in rats subjected to experimental lesions / Análise histológica do reparo de lesões da dura com tela de silicone em ratos submetidos à lesão experimental

ABSTRACT Objective To evaluate inflammatory reaction, fibrosis and neovascularization in dural repairs in Wistar rats using four techniques: simple suture, bovine collagen membrane, silicon mesh and silicon mesh with suture. Methods Thirty Wistar rats were randomized in five groups: the first was the control group, submitted to dural tear only. The others underwent durotomy and simple suture, bovine collagen membrane, silicon mesh and silicon mesh with suture. Animals were euthanized and the spine was submitted to histological evaluation with a score system (ranging from zero to 3) for inflammation, neovascularization and fibrosis. Results Fibrosis was significantly different between simple suture and silicon mesh (p=0.005) and between simple suture and mesh with suture (p=0.015), showing that fibrosis is more intense when a foreign body is used in the repair. Bovine membrane was significantly different from mesh plus suture (p=0.011) regarding vascularization. Inflammation was significantly different between simple suture and bovine collagen membrane. Conclusion Silicon mesh, compared to other commercial products available, is a possible alternative for dural repair. More studies are necessary to confirm these findings.

RESUMO Objetivo : Avaliar reação inflamatória, fibrose e neovascularização da reparação da lesão dural em ratos Wistar, comparando quatro diferentes técnicas: pontos simples, membrana de colágeno bovino, tela de silicone e tela de silicone associada a pontos simples. Métodos : Trinta ratos Wistar foram randomizados em cinco grupos: o primeiro foi um grupo controle, submetido somente à durotomia. Os outros também foram submetidos à durotomia, porém sofreram sutura simples, reparo com membrana de colágeno bovino, tela de silicone e tela de silicone com sutura. Os animais foram sacrificados, e a coluna foi submetida à avaliação histológica com um escore (variando de zero a 3) para inflamação, neovascularização e fibrose. Resultados : A fibrose foi significativamente diferente, comparando-se sutura simples e tela de silicone (p=0,005) e sutura simples e tela com fio de sutura (p=0,015), demonstrando que a fibrose foi mais intensa quando um corpo estranho foi utilizado na reparação. Membrana bovina foi significativamente diferente da tela mais sutura (p=0,011) em relação à vascularização. A inflamação foi significativamente diferente entre os grupos submetidos à sutura simples e ao reparo com membrana de colágeno bovino. Conclusão : A tela de silicone, comparada com produtos similares com disponibilidade comercial, é uma possível alternativa como protetor de dura-máter. Mais estudos são necessários para comprovar esses resultados.