Lumbar safety triangle: comparative study of coronal and coronal oblique planes in 3.0-T magnetic resonance imaging / Triângulo de segurança lombar: estudo comparativo dos planos coronal e coronal oblíquo em ressonância magnética 3.0-T

Abstract Objective: To compare the measurements of the lumbar safety triangle (Kambin's triangle) and the invasion of the dorsal root ganglion in the triangle in coronal and coronal oblique planes. Materials and Methods: A cross-sectional study, in which 210 3.0-T magnetic resonance images of L2-L5 were analyzed in coronal and coronal oblique planes. Exams with lumbar spine anomalies were excluded. Demographic (sex and age) and radiological variables were recorded by a single evaluator. Results: Most sample was female (57.1%), mean age 45.5 ± 13.3 (18-98 years). The measurements average, as well as the areas, gradually increased from L2 to L5. The dorsal root ganglion invaded the triangle in all images. The safety triangle average area was smaller in the coronal oblique plane than in the coronal plane. Of the seven dimensions of safety triangle obtained for each level of the lumbar spine, six were significantly smaller in the coronal oblique plane than in the coronal plane. The only dimension that showed no difference was the smallest ganglion dimension. Conclusion: The dimensions and areas investigated were smaller in coronal oblique plane, especially the area (difference > 1 mm). The analysis of the triangular zone in this plane becomes important in the preoperative assessment of minimally invasive procedures.

Resumo Objetivo: Comparar as medidas do triângulo de segurança lombar (triângulo de Kambin) e invasão do gânglio da raiz dorsal no triângulo nas incidências coronal e coronal oblíqua. Materiais e Métodos: Estudo transversal, em que foram analisadas 210 imagens de ressonância magnética 3.0-T de L2-L5 nos planos coronal e coronal oblíquo. Foram excluídos exames com anomalias da coluna lombar. Variáveis demográficas (sexo e idade) e radiológicas foram registradas por um único avaliador. Resultados: A maioria da amostra era do sexo feminino (57,1%), com idade média de 45,5 ± 13,3 (18-98 anos). A média das medidas, assim como as áreas, aumentaram gradativamente de L2 a L5. O gânglio da raiz dorsal invadiu o triângulo em todas as imagens. A área média do triângulo de segurança foi menor na incidência coronal oblíqua do que na incidência coronal. Das sete dimensões do triângulo de segurança obtidas para cada nível da coluna lombar, seis foram significativamente menores no plano coronal oblíquo do que no plano coronal. Única dimensão que não apresentou diferença foi a menor dimensão do gânglio. Conclusão: As dimensões e áreas investigadas foram menores na incidência coronal oblíqua, especialmente a área (diferença > 1 mm). A análise da zona triangular nesta incidência torna-se importante na avaliação pré-operatória de procedimentos minimamente invasivos.

Lumbar safety triangle: comparative study of coronal and coronal oblique planes in 3.0-T magnetic resonance imaging.

Objective: To compare the measurements of the lumbar safety triangle (Kambin's triangle) and the invasion of the dorsal root ganglion in the triangle in coronal and coronal oblique planes. Materials and Methods: A cross-sectional study, in which 210 3.0-T magnetic resonance images of L2-L5 were analyzed in coronal and coronal oblique planes. Exams with lumbar spine anomalies were excluded. Demographic (sex and age) and radiological variables were recorded by a single evaluator. Results: Most sample was female (57.1%), mean age 45.5 ± 13.3 (18-98 years). The measurements average, as well as the areas, gradually increased from L2 to L5. The dorsal root ganglion invaded the triangle in all images. The safety triangle average area was smaller in the coronal oblique plane than in the coronal plane. Of the seven dimensions of safety triangle obtained for each level of the lumbar spine, six were significantly smaller in the coronal oblique plane than in the coronal plane. The only dimension that showed no difference was the smallest ganglion dimension. Conclusion: The dimensions and areas investigated were smaller in coronal oblique plane, especially the area (difference > 1 mm). The analysis of the triangular zone in this plane becomes important in the preoperative assessment of minimally invasive procedures.

Objetivo: Comparar as medidas do triângulo de segurança lombar (triângulo de Kambin) e invasão do gânglio da raiz dorsal no triângulo nas incidências coronal e coronal oblíqua. Materiais e Métodos: Estudo transversal, em que foram analisadas 210 imagens de ressonância magnética 3.0-T de L2-L5 nos planos coronal e coronal oblíquo. Foram excluídos exames com anomalias da coluna lombar. Variáveis demográficas (sexo e idade) e radiológicas foram registradas por um único avaliador. Resultados: A maioria da amostra era do sexo feminino (57,1%), com idade média de 45,5 ± 13,3 (18­98 anos). A média das medidas, assim como as áreas, aumentaram gradativamente de L2 a L5. O gânglio da raiz dorsal invadiu o triângulo em todas as imagens. A área média do triângulo de segurança foi menor na incidência coronal oblíqua do que na incidência coronal. Das sete dimensões do triângulo de segurança obtidas para cada nível da coluna lombar, seis foram significativamente menores no plano coronal oblíquo do que no plano coronal. Única dimensão que não apresentou diferença foi a menor dimensão do gânglio. Conclusão: As dimensões e áreas investigadas foram menores na incidência coronal oblíqua, especialmente a área (diferença > 1 mm). A análise da zona triangular nesta incidência torna-se importante na avaliação pré-operatória de procedimentos minimamente invasivos.

Nerve root transfer from C4 to C5 in brachial plexus injuries. Anatomical study and description of the surgical technique.

Objective This is an anatomical study of C4 and C5 roots for nerve transfers in upper brachial plexus injuries, with surgical technique demonstration. Methods Fifteen brachial plexuses from both male and female cadavers were dissected. Morphological features of C4 and C5 roots were recorded and analyzed, followed by a neurotization simulation. Results In all dissections, C4 and C5 roots morphological features allowed their mobilization and neurotization with no need for a nerve graft. The surgical technique spared important regional nerve branches. Conclusion Based on these data, we conclude that C4-C5 nerve transfers are feasible and result in no additional neurological deficit in upper brachial plexus injuries.

Nerve root transfer from C4 to C5 in brachial plexus injuries. Anatomical study and description of the surgical technique / Transferência nervosa da raiz de C4 para C5 em lesões do plexo braquial. Estudo anatômico e descrição de técnica cirúrgica

Abstract Objective This is an anatomical study of C4 and C5 roots for nerve transfers in upper brachial plexus injuries, with surgical technique demonstration. Methods Fifteen brachial plexuses from both male and female cadavers were dissected. Morphological features of C4 and C5 roots were recorded and analyzed, followed by a neurotization simulation. Results In all dissections, C4 and C5 roots morphological features allowed their mobilization and neurotization with no need for a nerve graft. The surgical technique spared important regional nerve branches. Conclusion Based on these data, we conclude that C4-C5 nerve transfers are feasible and result in no additional neurological deficit in upper brachial plexus injuries.

Resumo Objetivo Estudo anatômico das raízes usadas na transferência nervosa de C4 para C5 nas lesões altas do plexo braquial, com demonstração da técnica cirúrgica. Métodos Dissecção de 15 plexos braquiais de cadáveres de ambos os sexos, registro e análise das características morfológicas das raízes de C4 e C5 e simulação de neurotização. Resultados As características morfológicas encontradas nas raízes de C4 e C5 em todas as dissecções permitiram a mobilização das mesmas e a realização de uma neurotização sem a necessidade de usar enxerto nervoso. A técnica cirúrgica permitiu preservar ramos nervosos importantes na região abordada. Conclusão Com base nos dados encontrados no presente estudo, podemos concluir que é possível realizar a transferência entre C4 e C5 sem provocar déficit neurológico adicional nas lesões altas de plexo braquial.

Anatomical description of the ventral and dorsal cervical rootlets in rats: A microsurgical study

Purpose: To describe the anatomical aspects of the cervical rootlets and to quantify the number of rootlets that compose C1 to T1. Methods: Twenty male rats were used in this study. The dorsal rootlets from C1 to T1 were analyzed. To study the ventral rootlets, the posterior root avulsion was performed using a microhook, allowing exposure of the ventral roots through manipulation of the denticulate ligament and arachnoid mater. The parameters analyzed were the number of ventral and dorsal rootlets by side and level. Results: The formation of the respective spinal nerve was observed in the spinal roots the union of the ventral and dorsal roots. In four animals the C1 spinal root had no dorsal and/or ventral contribution. There is no normal pattern of numerical normality of the dorsal and ventral rootlets. The average number of fascicles per root was 4.08, with a slight superiority on the left side. There was a slight superiority of the dorsal rootlets compared to the ventral rootlets. Conclusions: This investigation was the first to study cervical rootlets in rats. In 20% of the sample studied, the dorsal root of C1 was absent mainly on the left side. There is a nonlinear numerical increase from C1 to T1 in the rootlets. There is a numerical predominance of cervical fascicles on the left side, confronting several studies related to the functional predominance of right laterality, requiring new studies that correlate these variables.

Excisão cirúrgica de um osteocondroma de raiz nervosa da cauda equina de cão / Surgical excision of an osteochondroma in a nerve root of the cauda equina of a dog

Background: Spinal neoplasms are classified into extradural, intradural/extramedullary or intramedullary. Intradural/extramedullary tumors include meningiomas and nerve sheath tumors, which arise from meninges or peripheral nerves around the spinal cord. Clinical signs are related to dysfunction of the involved nerve and include pain, nerve root signature and atrophy. Osteochondromas are benign tumors located within the bone, on its surface or in extra-osseous regions, when they are classified as soft tissue osteochondoma. The aim of this study is to describe a case of an osteochondroma in a nervous root of the cauda equina in a dog, whose surgical resection allowed the resolution of the clinical signs.Case: A 12-year-old, male, Labrador Retriever dog, was presented with a 40-day history of progressive, painful, pelvic limb paresis, with no improvement when treated with analgesics and acupuncture. Neurological abnormalities included paraparesis, sometimes worse in the left pelvic limb, that was carried flexed at the level of the stifle, hindlimb atrophy, decreased interdigital reflexes and pain in the lumbar spinal region, mainly over L6 vertebra. Results of blood count and serum biochemical analysis were unremarkable. Computed tomography (CT) of the lumbosacral area was performed and the evaluation of images in transverse and reconstructed dorsal and sagittal planes allowed the visualization of a hyperattenuating and calcified round structure with 8 mm x 6 mm, in the left side of vertebral canal, at the level of caudal epiphysis of L6. Lumbosacral (L7-S1) CT abnormalities, as subchondral sclerosis, mild disc margin bulging, spondylosis deformans and foraminal proliferation were also observed but were considered clinically insignificant.[...]

Excisão cirúrgica de um osteocondroma de raiz nervosa da cauda equina de cão / Surgical excision of an osteochondroma in a nerve root of the cauda equina of a dog

Background: Spinal neoplasms are classified into extradural, intradural/extramedullary or intramedullary. Intradural/extramedullary tumors include meningiomas and nerve sheath tumors, which arise from meninges or peripheral nerves around the spinal cord. Clinical signs are related to dysfunction of the involved nerve and include pain, nerve root signature and atrophy. Osteochondromas are benign tumors located within the bone, on its surface or in extra-osseous regions, when they are classified as soft tissue osteochondoma. The aim of this study is to describe a case of an osteochondroma in a nervous root of the cauda equina in a dog, whose surgical resection allowed the resolution of the clinical signs.Case: A 12-year-old, male, Labrador Retriever dog, was presented with a 40-day history of progressive, painful, pelvic limb paresis, with no improvement when treated with analgesics and acupuncture. Neurological abnormalities included paraparesis, sometimes worse in the left pelvic limb, that was carried flexed at the level of the stifle, hindlimb atrophy, decreased interdigital reflexes and pain in the lumbar spinal region, mainly over L6 vertebra. Results of blood count and serum biochemical analysis were unremarkable. Computed tomography (CT) of the lumbosacral area was performed and the evaluation of images in transverse and reconstructed dorsal and sagittal planes allowed the visualization of a hyperattenuating and calcified round structure with 8 mm x 6 mm, in the left side of vertebral canal, at the level of caudal epiphysis of L6. Lumbosacral (L7-S1) CT abnormalities, as subchondral sclerosis, mild disc margin bulging, spondylosis deformans and foraminal proliferation were also observed but were considered clinically insignificant.[...](AU)

Correlation: impedance and tomography in implants insertion in lumbar arthrodesis / Correlação: impedância e tomografia na inserção de implantes em artrodese lombar / Correlación: impedancia y tomografía en la inserción de implantes en artrodesis lumbar

ABSTRACT Objective: To define whether the electroneurophysiological stimulation would be a safe method for reducing injuries in nerve roots during surgery of lumbar spine arthrodesis, as well as verify whether there is a direct correlation between the intraoperative impedance values and the distance from the medial cortical pedicle screw. Methods: Randomized retrospective multicenter study of 10 patients who underwent arthrodesis of lumbar spine after conservative treatment failure, with a total of 50 pedicle screws instrumented. Reliable and safe impedance values were measured in order to reduce the risk of injury to nerve roots in the perioperative period, and these values were compared with the distance between the screw and the medial cortical of the pedicle by CT scan, measured in the immediate post-operative period. Results: There is no direct correlation between the intraoperative impedance values and the distance from the screw to the medial cortical of the pedicle. Conclusion: The electroneurostimulation proved to be a reliable quantitative method to reduce the risk of injury to nerve roots during surgery of lumbar spine arthrodesis when the measured values are greater than 10mA.

RESUMO Objetivo: Definir se a estimulação eletroneurofisiológica seria um método seguro para redução de lesões em raízes nervosas no intraoperatório de artrodese de coluna lombar, bem como verificar se há correlação direta entre os valores de impedância transoperatória e a distância do parafuso e a cortical medial do pedículo. Métodos: Estudo retrospectivo, multicêntrico com seleção randômica consecutiva de 10 pacientes que realizaram artrodese de coluna lombossacra após falha de tratamento conservador, com um total de 50 parafusos pediculares instrumentados. Os valores confiáveis e seguros de impedância para diminuir os riscos de lesão em raízes nervosas foram aferidos no período perioperatório, sendo esses valores comparados com os da distância entre o parafuso e a cortical medial do pedículo na tomografia computadorizada, aferida no pós-operatório imediato. Resultados: Não há correlação direta entre os valores de impedância transoperatória e a distância do parafuso até a cortical medial do pedículo. Conclusão: A eletroneuroestimulação mostrou ser um método quantitativo seguro para diminuir os riscos de lesões em raízes nervosas no intraoperatório de artrodese de coluna lombar quando os valores aferidos são maiores que 10mA.

RESUMEN Objetivo: Definir si la estimulación electroneurofisiológica sería un método seguro para reducir las lesiones en las raíces nerviosas durante la cirugía de artrodesis de columna lumbar, así como verificar si hay correlación directa entre los valores de impedancia perioperatoria y la distancia entre tornillo y la cortical medial del pedículo. Métodos: Estudio retrospectivo, multicéntrico, con selección aleatoria consecutiva de 10 pacientes que fueron sometidos a la artrodesis de columna lumbosacra después de falla del tratamiento conservador, con un total de 50 tornillos pediculares instrumentados. Valores fiables y seguros de impedancia para reducir el riesgo de lesiones a las raíces nerviosas se midieron en el periodo perioperatorio, y estos valores se compararon con la distancia entre el tornillo y la cortical medial del pedículo en la tomografía computarizada, medida en el período postoperatorio inmediato. Resultados: No existe una correlación directa entre los valores de impedancia perioperatoria y la distancia desde el tornillo hasta la cortical medial del pedículo. Conclusión: La electroneuroestimulación mostró ser un método cuantitativo fiable para reducir el riesgo de lesiones a raíces nerviosas durante la cirugía de artrodesis de columna lumbar cuando los valores medidos son mayores que 10mA.

Cauda equina redundant nerve roots are associated to the degree of spinal stenosis and to spondylolisthesis / Associação entre a presença de raízes redundantes na cauda equina e a área seccional do saco dural avaliada por meio de ressonância magnética

To evaluate the association of redundant nerve roots of cauda equina (RNRCE) with the degree of lumbar spinal stenosis (LSS) and with spondylolisthesis. Method After Institutional Board approval, 171 consecutive patients were retrospectively enrolled, 105 LSS patients and 66 patients without stenosis. The dural sac cross-sectional area (CSA) was measured on T2w axial MRI at the level of L2-3, L3-4 and L4-5 intervertebral discs. Two blinded radiologists classified cases as exhibiting or not RNRCE in MRI. Intra- and inter-observer reproducibility was assessed. Results RNRCE were associated with LSS. RRNCE was more frequent when maximum stenosis<55 mm2. Substantial intra- observer agreement and moderate inter-observer agreement were obtained in the classification of RNRCE. Spondylolisthesis was identified in 27 patients and represented increased risk for RRNCE. Conclusion LSS is a risk factor for RNRCE, especially for dural sac CSA<55 mm2. LSS and spondylolisthesis are independent risk factors for RNRCE. .

Avaliar associação entre raízes nervosas redundantes da cauda eqüina (RNRCE) com grau de estenose do canal lombar (ECL) e espondilolistese. Método Após aprovação do Comitê de Ética, 171 pacientes foram selecionados retrospectivamente, 105 com ECL e 66 sem estenose. Foram realizadas mensurações da área seccional do saco dural em imagens axiais de RM ponderadas em T2 em L2/L3, L3/L4 e L4/L5. Presença ou não de RRNCE foi classificada de forma independente por dois radiologistas, às cegas. Concordância intra e inter-observador foi analisada. Resultados RNRCE foi associada à ECL e foi mais freqüente quando a máxima estenose encontrada foi <55mm2. Houve grande concordância intra-observador e moderada inter-observador na classificação das RRNCE. Espondilolistese foi identificada em 27 pacientes e representou maior risco para desenvolvimento de RNRCE. Conclusão ECL é fator de risco para RNRCE, especialmente com áreas seccionais <55mm2. ECL e espondilolistese representam fatores de risco independentes para desenvolvimento de RNRCE. .

Effective reinnervation of the quadriceps femoris by spinal ventral root cross-anastomosis in rats / Reinervação efetiva do quadríceps femoral pela anastomose cruzada via raiz espinhal ventral em ratos

PURPOSE: To study the effective recovery of the quadriceps femoris by spinal ventral root cross-anastomosis in rats. METHODS: End-to-end anastomosis was performed between the left L1 and L3 ventral roots using autogenous nerve graft ,and the right L1 and L3 roots were left intact. In control animals, the left L3 ventral root was cut and shortened, and anastomosis was not performed. Six months postoperatively, the movement of low extremities was detected by electrophysiological examination, hindlimb locomotion and basso, beattie and bresnahan (BBB) scoring at one, three, seven, 14, 21 and 28 days after SCI. Fluorescence retrograde tracing with TRUE BLUE (TB) and HE staining were performed to observe the nerve regeneration. RESULTS: Six months after surgery, the anastomotic nerve was smooth and not atrophic. The amplitudes of action potential were 7.63±1.86 mV and 6.0±1.92 mV respectively before and after the spinal cord hemisection. The contraction of left quadriceps femoris was induced by a single stimulation of the anastomotic nerve. The locomotion of left hindlimb was partially restored after spinal cord hemisection while creeping and climbing. In addition, there was significant difference in the BBB score at one, three and seven days after SCI. TB retrograde tracing and neurophysiologic observation indicated efficient reinnervation of the quadriceps femoris. CONCLUSION: The cross-anastomosis between spinal ventral root can partially reconstruct the function of quadriceps femoris following SCI and may have clinical implication for the treatment of human SCI.

OBJETIVO: Investigar a recuperação efetiva do músculo quadríceps femoral pela anastomose cruzada via raiz espinhal ventral em ratos. MÉTODOS: Anastomose término-terminal foi realizada entre as raízes ventrais L1 e L3 à esquerda usando enxerto autógeno de nervo e, à direita, as raízes L1 e L3 foram mantidas intactas. Nos animais controles, à esquerda, a raiz ventral de L3 foi cortada e encurtada sem realização de anastomose. Após seis meses, o movimento das extremidades posteriores foi estudado por exame eletrofisiológico, e pelo escore de basso, beattie e bresnahan (BBB) com um, três, sete, 14, 21 e 28 dias após SCI. Fluorescência retrograde feita com TRUE BLUE (TB) e coloração com HE foram realizadas para observar a regeneração do nervo. RESULTADOS: Seis meses após a cirurgia, a anastomose do nervo estava lisa e sem atrofia. As amplitudes dos potenciais de ação foram 7,63±1,86 mV e 6,0±1,92 mV respectivamente antes e após a hemisecção da medula espinhal. A contração do músculo quadríceps femoral foi induzida por um único estímulo do nervo anastomosado. A locomoção do membro posterior esquerdo foi parcialmente restaurada após hemisecção da medula espinhal ao rastejar e escalar. Ademais, houve diferença significante no escore BBB nos dias um, três e sete após SCI. O traçado da TB retrógrada e a observação neurofisiológica indicaram reinervação eficiente do quadríceps femoral. CONCLUSÃO: A anastomose cruzada entre as raízes espinhais ventrais podem reconstruir parcialmente a função do quadríceps femoral após SCI e pode ter implicação clínica para o tratamento da SCI.

Effective reinnervation of the quadriceps femoris by spinal ventral root cross-anastomosis in rats / Reinervação efetiva do quadríceps femoral pela anastomose cruzada via raiz espinhal ventral em ratos

PURPOSE: To study the effective recovery of the quadriceps femoris by spinal ventral root cross-anastomosis in rats. METHODS: End-to-end anastomosis was performed between the left L1 and L3 ventral roots using autogenous nerve graft ,and the right L1 and L3 roots were left intact. In control animals, the left L3 ventral root was cut and shortened, and anastomosis was not performed. Six months postoperatively, the movement of low extremities was detected by electrophysiological examination, hindlimb locomotion and basso, beattie and bresnahan (BBB) scoring at one, three, seven, 14, 21 and 28 days after SCI. Fluorescence retrograde tracing with TRUE BLUE (TB) and HE staining were performed to observe the nerve regeneration. RESULTS: Six months after surgery, the anastomotic nerve was smooth and not atrophic. The amplitudes of action potential were 7.63±1.86 mV and 6.0±1.92 mV respectively before and after the spinal cord hemisection. The contraction of left quadriceps femoris was induced by a single stimulation of the anastomotic nerve. The locomotion of left hindlimb was partially restored after spinal cord hemisection while creeping and climbing. In addition, there was significant difference in the BBB score at one, three and seven days after SCI. TB retrograde tracing and neurophysiologic observation indicated efficient reinnervation of the quadriceps femoris. CONCLUSION: The cross-anastomosis between spinal ventral root can partially reconstruct the function of quadriceps femoris following SCI and may have clinical implication for the treatment of human SCI.(AU)

OBJETIVO: Investigar a recuperação efetiva do músculo quadríceps femoral pela anastomose cruzada via raiz espinhal ventral em ratos. MÉTODOS: Anastomose término-terminal foi realizada entre as raízes ventrais L1 e L3 à esquerda usando enxerto autógeno de nervo e, à direita, as raízes L1 e L3 foram mantidas intactas. Nos animais controles, à esquerda, a raiz ventral de L3 foi cortada e encurtada sem realização de anastomose. Após seis meses, o movimento das extremidades posteriores foi estudado por exame eletrofisiológico, e pelo escore de basso, beattie e bresnahan (BBB) com um, três, sete, 14, 21 e 28 dias após SCI. Fluorescência retrograde feita com TRUE BLUE (TB) e coloração com HE foram realizadas para observar a regeneração do nervo. RESULTADOS: Seis meses após a cirurgia, a anastomose do nervo estava lisa e sem atrofia. As amplitudes dos potenciais de ação foram 7,63±1,86 mV e 6,0±1,92 mV respectivamente antes e após a hemisecção da medula espinhal. A contração do músculo quadríceps femoral foi induzida por um único estímulo do nervo anastomosado. A locomoção do membro posterior esquerdo foi parcialmente restaurada após hemisecção da medula espinhal ao rastejar e escalar. Ademais, houve diferença significante no escore BBB nos dias um, três e sete após SCI. O traçado da TB retrógrada e a observação neurofisiológica indicaram reinervação eficiente do quadríceps femoral. CONCLUSÃO: A anastomose cruzada entre as raízes espinhais ventrais podem reconstruir parcialmente a função do quadríceps femoral após SCI e pode ter implicação clínica para o tratamento da SCI.(AU)