[Translated article] Efficacy of early versus delayed spinal cord decompression in neurological recovery after traumatic spinal cord injury: Systematic review and meta-analysis.

STUDY DESIGN: Systematic review and meta-analysis. OBJECTIVE: To compare early (<24h) versus late (>24h) spinal cord decompression on neurological recovery in patients with acute spinal cord injury. METHODS: A systematic review was performed according to the PRISMA protocol to identify studies published up to December 2022. Prospective cohort studies and controlled trials comparing early versus delayed decompression on neurological recovery were included. Variables included number of patients, level of injury, treatment time, ASIA grade, neurological recovery, use of corticosteroids, and complications. For the meta-analysis, the "forest plot" graph was developed. The risk of bias of the included studies was assessed using the ROBINS-I22 and Rob223 tools. RESULTS: Six of the seven studies selected for our review were included in the meta-analysis, with a total of 1188 patients (592 patients in the early decompression group and 596 in the delayed decompression group), the mean follow-up was 8 months, in 5 studies used methylprednisolone, the most reported complications were thromboembolic cardiopulmonary events. Five studies showed significant differences in favour of early decompression (risk difference 0.10, 95% confidence interval 0.07-0.14, heterogeneity 46%). The benefit was greatest in cervical and incomplete injuries. CONCLUSION: There is scientific evidence to recommend early decompression in the first 24h after traumatic spinal cord injury, as it improves final neurological recovery, and it should be recommended whenever the patient and hospital conditions allow it to be safely done.

Efficacy of early versus delayed spinal cord decompression in neurological recovery after traumatic spinal cord injury: Systematic review and meta-analysis. / Eficacia de la descompresión medular precoz versus tardía en la recuperación neurológica tras lesión medular traumática. Revisión sistemática y metaanálisis.

STUDY DESIGN: Systematic review and meta-analysis. OBJECTIVE: To compare early (<24h) versus late (>24h) spinal cord decompression on neurological recovery in patients with acute spinal cord injury. METHODS: A systematic review was performed according to the PRISMA protocol to identify studies published up to December 2022. Prospective cohort studies and controlled trials comparing early versus delayed decompression on neurological recovery were included. Variables included number of patients, level of injury, treatment time, ASIA grade, neurological recovery, use of corticosteroids, and complications. For the meta-analysis, the «forest plot¼ graph was developed. The risk of bias of the included studies was assessed using the ROBINS-I22 and Rob223 tools. RESULTS: Six of the seven studies selected for our review were included in the meta-analysis, with a total of 1188 patients (592 patients in the early decompression group and 596 in the delayed decompression group), the mean follow-up was 8 months, in 5 studies used methylprednisolone, the most reported complications were thromboembolic cardiopulmonary events. Five studies showed significant differences in favor of early decompression (risk difference 0.10, 95% confidence interval 0.07-0.14, heterogeneity 46%). The benefit was greatest in cervical and incomplete injuries. CONCLUSION: There is scientific evidence to recommend early decompression in the first 24h after traumatic spinal cord injury, as it improves final neurological recovery, and it should be recommended whenever the patient and hospital conditions allow it to be safely done.

[Translated article] Relation between the volume of injected cement and the vertebral volume in the clinical outcome and in the appearance of leakage after a percutaneous vertebroplasty.

OBJECTIVES: To assess the connection between the volume of injected cement and the vertebral volume measured through a volumetric analysis with a computed tomography (CT scan) in relation to the clinical result and the appearance of a leakage in patients who underwent a percutaneous vertebroplasty after an osteoporotic fracture. MATERIALS AND METHODS: A prospective study of 27 patients (18 female-9 male) with an average age of 69 years old (50-81), and with a one-year follow-up. The study group presented 41 vertebrae with osteoporotic fractures that were treated with a percutaneous vertebroplasty with a bilateral transpedicular approach. The volume of injected cement was registered in each procedure and it was assessed together with the spinal volume measured through a volumetric analysis with CT scans. The percentage of the spinal filler was calculated. The appearance of cement leakage was proved by means of a simple radiography and a postoperative CT scan in all the cases. The leaks were classified according to the location in relation to the vertebral body (posterior, lateral, anterior and in the disc), and the significance (minor: smaller than the largest diameter of the pedicle; moderate: larger than the pedicle but smaller than the height of the vertebra; major: larger than the height of the vertebra). RESULTS: The average vertebra volume was 26.1cm3, the average volume of the injected cement was 2.0cm3 and the percentage of the average filler was 9%. A total of 15 leaks in 41 vertebrae appeared (37%). The leaks were posterior in 2 vertebrae, vascular in 8 and into the disc in 5 vertebrae. They were deemed as minor in 12 cases, moderate in 1 and major in 2 cases. The preoperative assessment of the pain was as it follows: VAS (8) and Oswestry (67%). The cessation of pain was immediate after a year with the following postoperative results: VAS (1.7) and Oswestry (19%). The only complication was the temporary neuritis with a spontaneous resolution. CONCLUSIONS: The injection of small amounts of cement, lower than the ones referred to by literary sources, obtains clinical results similar to the ones obtained by injecting higher amounts and it reduces the number of cement leaks and further complications.

Relation between the volume of injected cement and the vertebral volume in the clinical outcome and in the appearance of leakage after a percutaneous vertebroplasty. / Relación entre el volumen de cemento inyectado y el volumen vertebral en el resultado clínico y en la aparición de fugas tras vertebroplastia percutánea.

OBJECTIVES: To assess the connection between the volume of injected cement and the vertebral volume measured through a volumetric analysis with a computed tomography (CT scan) in relation to the clinical result and the appearance of a leakage in patients who underwent a percutaneous vertebroplasty after an osteoporotic fracture. MATERIALS AND METHODS: A prospective study of 27 patients (18 female-9 male) with an average age of 69 years old (50-81), and with a one-year follow-up. The study group presented 41 vertebrae with osteoporotic fractures that were treated with a percutaneous vertebroplasty with a bilateral transpedicular approach. The volume of injected cement was registered in each procedure and it was assessed together with the spinal volume measured through a volumetric analysis with CT scans. The percentage of the spinal filler was calculated. The appearance of cement leakage was proved by means of a simple radiography and a postoperative CT scan in all the cases. The leaks were classified according to the location in relation to the vertebral body (posterior, lateral, anterior and in the disc), and the significance (minor: smaller than the largest diameter of the pedicle; moderate: larger than the pedicle but smaller than the height of the vertebra; major: larger than the height of the vertebra). RESULTS: The average vertebra volume was 26.1 cc, the average volume of the injected cement was 2.0 cc and the percentage of the average filler was 9%. A total of 15 leaks in 41 vertebrae appeared (37%). The leaks were posterior in 2 vertebrae, vascular in 8 and into the disc in 5 vertebrae. They were deemed as minor in 12 cases, moderate in 1 and major in 2 cases. The preoperative assessment of the pain was as it follows: VAS (8) and Oswestry (67%). The cessation of pain was immediate after a year with the following postoperative results: VAS (1.7) and Oswestry (19%). The only complication was the temporary neuritis with a spontaneous resolution. CONCLUSIONS: The injection of small amounts of cement, lower than the ones referred to by literary sources, obtains clinical results similar to the ones obtained by injecting higher amounts and it reduces the number of cement leaks and further complications.

[The morbidity of the posterior iliac crest bone graft harvesting could be an overestimated fact. Study in patients with open posterolateral lumbar fusion]. / La morbilidad del sitio donante de injerto de cresta ilíaca posterior podría ser un hecho sobreestimado. Estudio en pacientes con fusión lumbar posterolateral abierta.

INTRODUCTION: spinal fusion is used to treat, among other pathologies, the degenerative intervertebral disc disease. Autologous iliac crest bone grafting is the golden standard treatment for increasing the rate of fusion; however, it isn't free of complications. OBJECTIVES: to investigate whether patients who have posterior iliac crest graft harvesting and are blinded to the donor site, can identify from which side the graft was harvested, and whether the intensity of this pain is related to the amount of graft obtained. MATERIAL AND METHODS: prospective, experimental, randomized and comparative, single-blind study. Adult patients who underwent primary instrumented open posterolateral lumbar fusion with autologous iliac crest bone graft between July 2019 and April 2020 were included. Patients were divided into two randomized groups. The amount of graft to be harvested was according to surgical needs. The patients were asked about pain according to the visual analogue scale in the first, third and sixth months after surgery, always requesting that the most painful side be identified. RESULTS: a total of 44 patients (n = 23 right crest, n = 21 left crest) were analyzed. Most patients were unable to identify the side from which the bone graft was harvested, with a statistically significant difference (p-value 0.0001). CONCLUSION: iliac crest bone graft harvesting is an effective and safe procedure that improves the rates of fusion without increasing the patient's morbidity.

INTRODUCCIÓN: la fusión espinal es utilizada para tratar, entre otras patologías, las enfermedades degenerativas discales. El injerto óseo autólogo de cresta ilíaca es el estándar de oro para aumentar las probabilidades de fusión; sin embargo, no está exento de complicaciones. OBJETIVOS: investigar si los pacientes a los que se les recolecta injerto de cresta ilíaca posterior y son cegados al lado del sitio donante, pueden identificar de qué lado se tomó dicho injerto y si la intensidad de este dolor está en relación con la cantidad de injerto obtenido. MATERIAL Y MÉTODOS: trabajo prospectivo, experimental, aleatorizado y comparativo, simple ciego. Se incluyeron pacientes adultos operados entre Julio de 2019 hasta Abril de 2020, a los cuales se les realizó una cirugía primaria de artrodesis lumbar posterolateral abierta instrumentada, con colocación de injerto óseo autólogo de cresta ilíaca. Se dividió a los pacientes en dos grupos aleatorizados. La cantidad de injerto a recolectar fue de acuerdo a las necesidades quirúrgicas. Se interrogó por el dolor según escala visual analógica al primer, tercer y sexto mes de la cirugía, siempre solicitando que se identifique el lado más doloroso. RESULTADOS: se analizaron 44 pacientes (n = 23 cresta derecha, n = 21 cresta izquierda). La mayoría de los pacientes no lograron identificar el lado del cual se obtuvo el injerto óseo, con una diferencia estadística ampliamente significativa (p = 0.0001). CONCLUSIÓN: la obtención de injerto óseo de cresta ilíaca es un procedimiento efectivo y seguro, que mejora las probabilidades de fusión sin aumentar la morbilidad del paciente.

[Is the Michigan State University lumbar disc herniation classification reliable among spine surgeons?] / ¿Es confiable la clasificación de la hernia de disco lumbar de la Universidad Estatal de Míchigan entre cirujanos de columna?

INTRODUCTION: there are numerous classifications for herniated discs, such classifications guide professionals about the severity of the lesion, the possible clinical picture of the patient, the most appropriate treatment and are undoubtedly a predictive tool to project the possible results of the therapies used. The main purpose of this work is to validate the inter- and intra-observer reliability of the Michigan State University (MSU) classification among the spine surgeons of our service and also to know the risk factors associated with the patients who underwent lumbar discectomy, the most affected disc level, the clinical presentation and the previous treatments performed in the patients treated by our team. MATERIAL AND METHODS: 50 nuclear magnetic resonance (MR) images in axial T2 section corresponding to the "maximum disc herniation" level were selected from patients diagnosed and submitted to meningo-radicular release surgery and single level lumbar discectomy retrospectively in the last two years from our database; these images were distributed among three spine surgeons of our institution. The three spine surgeons gave a specific classification for each MR image based on the MSU classification, then at an interval of seven days one of the three surgeons reclassified the images. The degree of agreement between surgeons was analyzed by calculating interobserver and intraobserver reliability using kappa statistical analysis. RESULTS: the analysis of the kappa coefficient indicated that most of the comparisons by observer gave a "good" concordance strength, the kappa index was higher than 0.64 in all the possible comparisons of the observations. In relation to the number of coincidences, in 60% of the patients there was a total coincidence between the three surgeons, with two coincidences in 24%, and in 16% there was no coincidence at all. For the intraobserver analysis the kappa index was 0.953 with a very good concordance strength, the observed agreement was 96%. CONCLUSION: our research shows a good reliability in the MSU classification among spine surgeons of our institution, as well as very good when reclassifying the intraobserver; we believe that having a sagittal MRI slice to classify them would be very useful, more research is needed to give a prognostic value to the location and size of the hernia and its relation with the surgical indication.

INTRODUCCIÓN: existen numerosas clasificaciones para las hernias de disco, dichas clasificaciones orientan a los profesionales acerca de la gravedad de la lesión, del posible cuadro clínico del paciente, del tratamiento más adecuado y constituyen, sin lugar a dudas, una herramienta predictiva para proyectar los posibles resultados de las terapias utilizadas. El propósito principal de este trabajo es validar la confiabilidad interobservador e intraobservador de la clasificación de la Universidad Estatal de Míchigan (MSU) entre los cirujanos de columna de nuestro servicio y además, conocer los factores de riesgo asociados con los pacientes que fueron intervenidos con discectomía lumbar, el nivel de disco más afectado, la presentación clínica y los tratamientos previos realizados en los pacientes tratados por nuestro equipo. MATERIAL Y MÉTODOS: fueron seleccionadas 50 imágenes de resonancia magnética nuclear (RM) en el corte axial de T2 correspondiente al nivel de "hernia discal máxima" de pacientes diagnosticados y sometidos a cirugía de liberación meningo radicular y discectomía lumbar de un solo nivel de manera retrospectiva en los últimos dos años de nuestra base de datos, estas imágenes se distribuyeron entre tres cirujanos especialistas en columna de nuestra institución. Los tres cirujanos de columna dieron una clasificación específica para cada imagen de RM basada en la clasificación de la MSU, luego en un intervalo de siete días uno de los tres cirujanos volvió a clasificar las imágenes. El grado de acuerdo entre los cirujanos se analizó calculando la confiabilidad interobservador e intraobservador mediante el análisis estadístico kappa. RESULTADOS: el análisis del coeficiente de kappa indicó que en la mayoría de las comparaciones por observador dieron una fuerza de concordancia "buena", el índice de kappa fue superior a 0.64 en todas las posibles comparaciones de las observaciones. En relación con la cantidad de coincidencias, en 60% de los pacientes hubo una coincidencia total entre los tres cirujanos, con dos coincidencias 24% y en 16% no hubo ninguna coincidencia. Para el análisis intraobservador el índice de kappa fue de 0.953 con una fuerza de concordancia muy buena, el acuerdo observado fue de 96%. CONCLUSIÓN: nuestra investigación demuestra una confiabilidad buena en la clasificación de la MSU entre cirujanos de columna de nuestra institución así como muy buena al reclasificar el intraobservador. Creemos que tener un corte sagital de RM para clasificarlas sería de gran utilidad. Se necesitan más investigaciones para dar un valor pronóstico a la ubicación y tamaño de la hernia y su relación con la indicación quirúrgica.

¿Es confiable la clasificación de la hernia de disco lumbar de la Universidad Estatal de Míchigan entre cirujanos de columna? / Is the Michigan State University lumbar disc herniation classification reliable among spine surgeons?

Resumen: Introducción: Existen numerosas clasificaciones para las hernias de disco, dichas clasificaciones orientan a los profesionales acerca de la gravedad de la lesión, del posible cuadro clínico del paciente, del tratamiento más adecuado y constituyen, sin lugar a dudas, una herramienta predictiva para proyectar los posibles resultados de las terapias utilizadas. El propósito principal de este trabajo es validar la confiabilidad interobservador e intraobservador de la clasificación de la Universidad Estatal de Míchigan (MSU) entre los cirujanos de columna de nuestro servicio y además, conocer los factores de riesgo asociados con los pacientes que fueron intervenidos con discectomía lumbar, el nivel de disco más afectado, la presentación clínica y los tratamientos previos realizados en los pacientes tratados por nuestro equipo. Material y métodos: Fueron seleccionadas 50 imágenes de resonancia magnética nuclear (RM) en el corte axial de T2 correspondiente al nivel de «hernia discal máxima¼ de pacientes diagnosticados y sometidos a cirugía de liberación meningo radicular y discectomía lumbar de un solo nivel de manera retrospectiva en los últimos dos años de nuestra base de datos, estas imágenes se distribuyeron entre tres cirujanos especialistas en columna de nuestra institución. Los tres cirujanos de columna dieron una clasificación específica para cada imagen de RM basada en la clasificación de la MSU, luego en un intervalo de siete días uno de los tres cirujanos volvió a clasificar las imágenes. El grado de acuerdo entre los cirujanos se analizó calculando la confiabilidad interobservador e intraobservador mediante el análisis estadístico kappa. Resultados: El análisis del coeficiente de kappa indicó que en la mayoría de las comparaciones por observador dieron una fuerza de concordancia «buena¼, el índice de kappa fue superior a 0.64 en todas las posibles comparaciones de las observaciones. En relación con la cantidad de coincidencias, en 60% de los pacientes hubo una coincidencia total entre los tres cirujanos, con dos coincidencias 24% y en 16% no hubo ninguna coincidencia. Para el análisis intraobservador el índice de kappa fue de 0.953 con una fuerza de concordancia muy buena, el acuerdo observado fue de 96%. Conclusión: Nuestra investigación demuestra una confiabilidad buena en la clasificación de la MSU entre cirujanos de columna de nuestra institución así como muy buena al reclasificar el intraobservador. Creemos que tener un corte sagital de RM para clasificarlas sería de gran utilidad. Se necesitan más investigaciones para dar un valor pronóstico a la ubicación y tamaño de la hernia y su relación con la indicación quirúrgica.

Abstract: Introduction: There are numerous classifications for herniated discs, such classifications guide professionals about the severity of the lesion, the possible clinical picture of the patient, the most appropriate treatment and are undoubtedly a predictive tool to project the possible results of the therapies used. The main purpose of this work is to validate the inter- and intra-observer reliability of the Michigan State University (MSU) classification among the spine surgeons of our service and also to know the risk factors associated with the patients who underwent lumbar discectomy, the most affected disc level, the clinical presentation and the previous treatments performed in the patients treated by our team. Material and methods: 50 nuclear magnetic resonance (MR) images in axial T2 section corresponding to the «maximum disc herniation¼ level were selected from patients diagnosed and submitted to meningo-radicular release surgery and single level lumbar discectomy retrospectively in the last two years from our database; these images were distributed among three spine surgeons of our institution. The three spine surgeons gave a specific classification for each MR image based on the MSU classification, then at an interval of seven days one of the three surgeons reclassified the images. The degree of agreement between surgeons was analyzed by calculating interobserver and intraobserver reliability using kappa statistical analysis. Results: The analysis of the kappa coefficient indicated that most of the comparisons by observer gave a «good¼ concordance strength, the kappa index was higher than 0.64 in all the possible comparisons of the observations. In relation to the number of coincidences, in 60% of the patients there was a total coincidence between the three surgeons, with two coincidences in 24%, and in 16% there was no coincidence at all. For the intraobserver analysis the kappa index was 0.953 with a very good concordance strength, the observed agreement was 96%. Conclusion: Our research shows a good reliability in the MSU classification among spine surgeons of our institution, as well as very good when reclassifying the intraobserver; we believe that having a sagittal MRI slice to classify them would be very useful, more research is needed to give a prognostic value to the location and size of the hernia and its relation with the surgical indication.

Neurological injury as a complication of spinal surgery: incidence, risk factors, and prognosis.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: To assess the rate, injury site, aetiology and outcomes in elective spinal surgery patients who sustained a spinal cord injury (SCI). SETTING: SCI national centre Toledo, Spain. METHODS: The study sample included patients who sustained an SCI after elective spinal surgery from 2013 to 2017. Oncological patients and patients receiving interventional therapies were excluded. Data collected included: demographics, aetiology, precipitating cause, injury mechanism, injury site, neurological status (AIS), SCIMIII at admission and discharge, hypertension, diabetes mellitus, obesity, dyslipidemia, depression and hospital length of stay. RESULTS: One thousand two hundred and eighty-two patients were admitted in this period of whom 114 met the inclusion criteria with a median (IQR) age of 58 (45-69) years; 46% female. The prevalence of SCI as a complication following spinal surgery in the total number of patients admitted to our centre was 9%. In 43%, the injury was to the dorsal spine with T12 being the most common neurological level of injury (20% of cases following laminectomy secondary to spinal canal stenosis). The most frequent precipitating cause was epidural haematoma (38% of cases). The median (IQR) SCIMIII scores at admission and discharge were (31) points (20-54) and (67) points (34-81), respectively. General AIS at admission were C (35%) and D at discharge (54%). The presence of hypertension, diabetes mellitus, obesity and dyslipidemia adjusted by age was not linked to a higher complication rate. The median (IQR) hospital length of stay was 120 days (60-189). CONCLUSION: In total 8.9% of patients admitted with SCI were the result of elective spinal surgery.

[Application of vancomycin powder on graft. Does the fusion of the rabbits spine is affected?] / Aplicación de vancomicina en polvo sobre el injerto. ¿Afecta la fusión de columna en conejos?

INTRODUCTION: In vitro studies suggest that vancomycin is highly cytotoxic for osteoblasts. However, several clinical studies in vivo have not provided evidence or determined that effect on osteogenesis. The aim of this work was to investigate the effect of topical vancomycin on a lumbar arthrodesis model on New Zealand white rabbits. MATERIAL AND METHODS: Double-blind randomized experimental study. Posterolateral spinal fusion was performed on 30 rabbits, divided into two groups, A: graft/placebo, B: graft/vancomycin. After sacrificing them, the bone callus was evaluated with axial tomography and classified into three groups: no fusion (0), partial/incomplete fusion (1) and fusion (2). The samples were also histologically analyzed. The associations between the presence of fusion (complete/incomplete) and the group tested were estimated using Poisson log-linear models with two covariates. Adherences to histologically obtained responses were studied using contingency tables and 2 tests. The significance level was set equal to 0.05. RESULTS: Treatment with vancomycin has 30% (0.30. CI 95%: 0.12-0.94) less chance compared to the placebo group, of presenting complete fusion. In other words, the vancomycin group has 2.3 times (CI 95%: 1.02-4.91) more likelyhood, compared to placebo, to have incomplete fusion. CONCLUSION: The application of vancomycin powder mixed with graft reduces fusion rates by 30%, but at doses 5 times higher than those routinely used in arthrodesis by the authors medical team.

INTRODUCCIÓN: Estudios in vitro sugieren que la vancomicina es altamente citotóxica para los osteoblastos. No obstante, diversos estudios clínicos in vivo no han aportado evidencias o determinado ese efecto en la osteogénesis. El objetivo del presente trabajo fue investigar el efecto de la vancomicina tópica, en un modelo de artrodesis lumbar sobre conejos blancos neozelandeses. MATERIAL Y MÉTODOS: Estudio experimental randomizado doble ciego. Se realizó fusión espinal posterolateral a 30 conejos, divididos en dos grupos, A: injerto/placebo, B: injerto/vancomicina. Luego de sacrificarlos, se evaluó el callo óseo con tomografía axial, clasificándolos en tres grupos: sin fusión (0), fusión parcial/incompleta (1) y fusión (2). Las muestras también fueron analizadas histológicamente. Las asociaciones entre presencia de fusión (completa/incompleta) y el grupo ensayado fueron estimadas con modelos log-lineales de Poisson con dos covariables. Las adherencias con las respuestas obtenidas histológicamente fueron estudiadas usando tablas de contingencia y test 2. El nivel de significación se fijó igual a 0.05. RESULTADOS: El tratamiento con vancomicina tiene 30% (0.30. IC 95%: 0.12-0.94) menos probabilidad respecto al grupo placebo de presentar fusión completa. En otros términos, el grupo vancomicina tiene 2.3 veces (IC 95%: 1.02-4.91) más probabilidad, respecto del placebo, de tener fusión incompleta. CONCLUSIÓN: La aplicación de vancomicina en polvo mezclada con injerto reduce 30% las tasas de fusión, pero a dosis cinco veces más alta que las usadas rutinariamente en artrodesis por el equipo médico de los autores.