[Publications on spine surgery in Mexico: a bibliometric study]. / Estudio bibliométrico de las publicaciones en cirugía de columna en México.

INTRODUCTION: bibliometric analysis is a useful way of assessing the past, present and future publications related to a given area in a qualitative and quantitative way. OBJECTIVE: to determine characteristics of national authors productivity in the field of spine surgery research across the time. MATERIAL AND METHODS: an online research was performed using the Elsevier´s database Scopus in October, 2021. All studies were assessed for the following parameters: year, title, access, language, journal, type of article, focus of research, objective of research, cites, authors and institutions. RESULTS: a total of 404 publications were identified between 1973 and 2021. Between 1991-2000 decade to 2011-2021 decade the number of published articles tended to increase by 68.28 times. The largest number of articles was from South-Central Region (66.16%), followed by Western (15.03%) and Northwest (8.27%). The highest h-index was found for USA journals (102). The highest number of articles was published in Coluna/Columna (15.53%), followed by Cirugía y Cirujanos (10.52%) and Acta Ortopédica Mexicana (8.52%). Instituto Nacional de Rehabilitación published the largest number of articles (17.57%), followed by Centro Médico Nacional de Occidente del IMSS (6.67%) and Centro Médico ABC (5.44%). CONCLUSIONS: the number of articles published in the field of spine surgery in Mexico has increased rapidly in the past 15 years. In terms of quality, publications written in English are the most cited. The geographical distribution of research in Mexico is centralized, the largest number of publications was from South-Central Region of Mexico.

INTRODUCCIÓN: el análisis bi­bliométrico es una forma útil de evaluar el pasado, el pre­sente y el futuro de las publicaciones relacionadas con un área determinada de forma cualitativa y cuantitativa. OBJETIVO: determinar las características de la productividad nacional en investigación escrita por autores mexicanos en el campo de cirugía de columna a través del tiempo. MATERIAL Y MÉTODOS: se realizó una búsqueda exhaustiva en línea en Octubre de 2021 utilizando la base de datos Scopus desarrollada por Elsevier. La información de las publicaciones recolectadas fue la siguiente: año, título, acceso, idioma, revista, tipo de artículo, tema, objetivo, citas, autores e instituciones de afiliación. RESULTADOS: se identificó un total de 404 publicaciones entre 1973 y 2021. El número de publicaciones entre la década 1991-2000 y 2011-2021 incrementó 68.28 veces. La mayoría de las publicaciones se realizaron en instituciones de la región centro-sur de México (66.16%), seguida de la región occidente (15.03%) y noreste (8.27%). El índice H más alto encontrado fue de revistas de origen estadounidense (102). La mayor parte de las publicaciones se realizó en la revista Coluna/Columna (15.53%), seguida de Cirugía y Cirujanos (10.52%) y de Acta Ortopédica Mexicana (8.52%). La institución con la más alta productividad fue el Instituto Nacional de Rehabilitación "Luis Guillermo Ibarra Ibarra" (17.57%), seguida del Centro Médico Nacional de Occidente del IMSS (6.67%) y del Centro Médico ABC (5.44%). CONCLUSIONES: el número de artículos publicados en el campo de cirugía de columna ha incrementado rápidamente en los últimos 15 años. Las publicaciones escritas en inglés son las más citadas. La distribución geográfica de la investigación en este campo en México está centralizada, realizándose la mayor parte de las publicaciones en la región centro-sur del país (66.16%).

Incisional hernia, a rare complication of the anterolateral transpsoas approach.

INTRODUCTION: Anterolateral transpsoas approach is considered as safe access to the retroperitoneum with low risk of complications. The most frequent described complications due to this approach were nerve, bowel, urethral and kidney injury. An incisional hernia is a rare complication in anterolateral approach, as a result of a nonhealing surgical wound or late disruption of the fascia; it occurs in 1% of the incisions after primary closure. CASE DESCRIPTION: We report a 75-year-old woman who underwent spinal surgery with a double approach, consisting of an anterolateral transpsoas approach and posterior lumbar approach. Two months post-surgery, the patient developed a lateral abdominal tumor at the surgical site. CONCLUSION: To prevent incisional hernia, a meticulous dissection must be performed to avoid muscle denervation and weakening of the abdominal wall, as well as proper repair of the fascia its critical to ensure an adequate closure of the wound.

INTRODUCCIÓN: El Abordaje anterolateral transpsoas se considera como un acceso seguro al retroperitoneo con bajo riesgo de complicaciones. Las complicaciones descritas más frecuentes debido a este abordaje fueron lesiones nerviosas, intestinales, uretrales y renales. Una hernia incisional es una complicación poco frecuente en el abordaje anterolateral, como resultado de una herida quirúrgica no cicatrizada o una ruptura tardía de la fascia; ocurre en 1% de las incisiones después del cierre primario. CASO CLÍNICO: Informamos de una mujer de 75 años que se sometió a una cirugía de columna vertebral con un doble abordaje quirúrgico, que consiste en un abordaje anterolateral transpsoas y un abordaje lumbar posterior. Dos meses después de la cirugía, el paciente desarrolló un tumor abdominal lateral en el sitio quirúrgico. CONCLUSIÓN: Para prevenir la hernia incisional, se debe realizar una disección meticulosa para evitar la denervación muscular y el debilitamiento de la pared abdominal, así como la correcta reparación de la fascia es crítico para asegurar un cierre adecuado de la herida.

Incisional hernia, a rare complication of the anterolateral transpsoas approach / Hernia incisional, una complicación poco frecuente del abordaje transpsoas anterolateral

Abstract: Introduction: Anterolateral transpsoas approach is considered as safe access to the retroperitoneum with low risk of complications. The most frequent described complications due to this approach were nerve, bowel, urethral and kidney injury. An incisional hernia is a rare complication in anterolateral approach, as a result of a nonhealing surgical wound or late disruption of the fascia; it occurs in 1% of the incisions after primary closure. Case description: We report a 75-year-old woman who underwent spinal surgery with a double approach, consisting of an anterolateral transpsoas approach and posterior lumbar approach. Two months post-surgery, the patient developed a lateral abdominal tumor at the surgical site. Conclusion: To prevent incisional hernia, a meticulous dissection must be performed to avoid muscle denervation and weakening of the abdominal wall, as well as proper repair of the fascia its critical to ensure an adequate closure of the wound.

Resumen: Introducción: El Abordaje anterolateral transpsoas se considera como un acceso seguro al retroperitoneo con bajo riesgo de complicaciones. Las complicaciones descritas más frecuentes debido a este abordaje fueron lesiones nerviosas, intestinales, uretrales y renales. Una hernia incisional es una complicación poco frecuente en el abordaje anterolateral, como resultado de una herida quirúrgica no cicatrizada o una ruptura tardía de la fascia; ocurre en 1% de las incisiones después del cierre primario. Caso clínico: Informamos de una mujer de 75 años que se sometió a una cirugía de columna vertebral con un doble abordaje quirúrgico, que consiste en un abordaje anterolateral transpsoas y un abordaje lumbar posterior. Dos meses después de la cirugía, el paciente desarrolló un tumor abdominal lateral en el sitio quirúrgico. Conclusión: Para prevenir la hernia incisional, se debe realizar una disección meticulosa para evitar la denervación muscular y el debilitamiento de la pared abdominal, así como la correcta reparación de la fascia es crítico para asegurar un cierre adecuado de la herida.

Lumbar degenerative spondylolisthesis II: treatment and controversies.

There are various approaches and surgical techniques with the objective of nerve root decompression, restrict mobility, and fusion of the listhesis. Among the techniques, posterior interbody fusion combines direct and indirect root decompression with the fusion between vertebral bodies, placing an autologous bone graft between transverse apophysis and vertebral bodies. Transforaminal lumbar and posterior interbody fusion, on the same way, look to decompress and fuse but with a different approach to the spine. The anterior approach for interbody fusion provides a better fusion rate. Lateral lumbar interbody fusion is considered less invasive, with an anterolateral transpsoas approach. The lumbar fusion technique in degenerative spondylolisthesis must be individualized. Non-fusion decompression is considered a less invasive procedure. Various studies suggest that decompression has better results when fusion is added. Surgery had several potential benefits and greater improvement in those patients who fail conservative management. An optimal technique is not conclusively identified.

El tratamiento de la espondilolistesis degenerativa lumbar es específico para cada etapa de la enfermedad y el manejo quirúrgico no debe de ser la primera elección en la mayoría de los casos. El manejo conservador está basado en el uso de antiinflamatorios no esteroideos, control de peso y rehabilitación. En caso de falla después de cuatro a seis semanas, el siguiente paso es la infiltración facetaria. En caso de dolor persistente, alteraciones neurológicas o claudicación neurogénica el siguiente paso es la cirugía. Existen varios abordajes y técnicas quirúrgicas con el objetivo de descomprimir las raíces nerviosas, restringir la movilidad y fusionar la listesis. Entre las técnicas quirúrgicas, la fusión posterior combina la descompresión directa e indirecta con artrodesis entre los cuerpos vertebrales, colocando injerto entre las apófisis transversas y los cuerpos vertebrales. La artrodesis intersomática transforaminal y posterior buscan de la misma manera la descompresión y fusión, pero con un abordaje distinto. El abordaje anterior para artrodesis intersomática provee la mejor tasa de fusión. La artrodesis intersomática lateral se considera un procedimiento menos invasivo, con un abordaje anterolateral transpsoas. La técnica de artrodesis lumbar en la espondilolistesis debe ser individualizada. La descompresión sin artrodesis se considera un procedimiento menos invasivo; varios estudios sugieren que la descompresión tiene mejores resultados cuando se agrega una artrodesis. La cirugía tiene múltiples beneficios posibles en pacientes en quienes el tratamiento conservador ha fallado. No se ha identificado una técnica óptima de tratamiento.

Degenerative spondylolisthesis I: general principles.

Lumbar degenerative spondylolisthesis is the result of the progression from degenerative changes in the intervertebral disc and facet joints that lead to destabilizing one or more vertebral segments. It is characterized by the anterior sliding of the vertebral body secondary to the sagittalization of the facet joints. Wiltse, Newman, and Macnab classified it as type III. It is a pathology typical of elderly patients that predominate in women with a ratio of 5:1 compared to men; the most affected segment is L4-L5, the listhesis rarely exceeds 30% slip. It may or may not generate clinical manifestations, and the severity of these does not always correlate with the degree of sliding. The cardinal symptom is lumbar pain with or without radicular pain. Neurogenic claudication occurs in 75% of patients; it is caused by blood hypoperfusion secondary to the compression of the nerve roots, manifesting as pain in the lower limbs with variable walking distances. For the diagnosis of degenerative spondylolisthesis, comprehensive evaluation with static, dynamic radiographic studies in a standing position and magnetic resonance imaging are essential. The conservative treatment is the first-line therapy; it includes analgesics, anti-inflammatories, physiotherapy.

La espondilolistesis degenerativa lumbar es el resultado de la progresión de los cambios degenerativos en el disco intervertebral y las articulaciones facetarias que termina por inestabilizar uno o varios segmentos vertebrales. Se caracteriza por el deslizamiento anterior del cuerpo vertebral secundario a la sagitalización de las facetas articulares, Wiltse, Newman y Macnab la clasifican como tipo III. Es una patología propia de los pacientes de la tercera edad, predomina en mujeres con una relación de 5:1 respecto a los varones, el segmento más afectado es L4-L5, el desplazamiento rara vez supera el 30% de deslizamiento. Puede o no generar manifestaciones clínicas y la severidad de éstas, no siempre correlaciona con el grado de listesis. El síntoma cardinal es el dolor lumbar con o sin dolor radicular; mientras que la claudicación neurogénica se presenta en 75% de los pacientes, es causada por la hipoperfusión sanguínea secundaria a la compresión de las raíces nerviosas y se manifiesta como dolor en los miembros inferiores, con la deambulación a distancias variables. Para el diagnóstico de la espondilolistesis degenerativa es indispensable una evaluación integral con estudios radiográficos estáticos, dinámicos en posición de pie y resonancia magnética. La primera línea de tratamiento es el manejo conservador, este incluye analgésicos, antiinflamatorios, fisioterapia.

[Os odontoideum. Presentation in adult age]. / Os odontoideum. Presentación en edad adulta.

The Os odontoideum is a variable oval or round ossicle with a smooth cortical border, which partially corresponds to the odontoid process, without having continuity with the rest of C2 bone. The multifactorial etiology causes instability and clinically translates into pain and compression data into neural structures. The treatment of choice is surgical and techniques have been developed that focus on preserving the stability of the segment. We present the case of a 23-year-old female patient, who begins to suffer at 8 years of age, refers to moderate to severe cervicalgia, which develops with paresthesias in the left hemisphere and later paresis of the left thoracic limb. Physical examination showed hypoaesthesia of the left hemisphere, as well as paresis of the left thoracic limb. Extension studies demonstrate chronic axonal lesion from C1 to C3, predominantly left, imaging studies showing axial instability and magnetic resonance bulbar compression. The patient receives surgical treatment consisting of posterior fixation C1-C2, evolving satisfactorily.

Os odontoideum es un osículo oval o redondo de tamaño variable con un borde cortical liso, que se corresponde parcialmente con la apófisis odontoides, sin tener continuidad ósea con el resto de C2. La etiología es multifactorial, causa inestabilidad y clínicamente se traduce en dolor y datos de compresión a las estructuras neurales. El tratamiento de elección es quirúrgico y se han desarrollado técnicas que se enfocan en conservar la estabilidad del segmento. Presentamos el caso de una mujer de 23 años, inicia padecimiento a los ocho años, refiere cervicalgia moderada a intensa, que evoluciona con parestesias en hemicuerpo izquierdo y posteriormente paresia de miembro torácico izquierdo. A la exploración física se evidencia hipoestesia de hemicuerpo izquierdo, así como paresia de miembro torácico izquierdo. Los estudios de extensión demuestran lesión axonal crónica de C1 a C3, de predominio izquierdo, los estudios de imagen evidencian inestabilidad axial y la resonancia magnética compresión bulbar. La paciente recibe tratamiento quirúrgico consistente en fijación posterior C1-C2, evolucionando satisfactoriamente.

[The Mexican Association of Spine Surgery Guideline for the decision making to perform a spine surgery during the COVID-19 pandemic]. / Recomendaciones de Asociación Mexicana de Cirujanos de Columna para la toma de decisiones para realizar una cirugía de columna durante la pandemia de COVID-19.

The COVID-19 pandemic has changed in a significant way the lifestyle in the world and in Mexico. Medicine is not an exception, therefore, modifications in how the assessment and treatment of our patients is done, is mandatory to assure the safeness of the patient, the medical team, the hospital staff, the medical facility, and the community. In this paper, the Mexican Association of Spine Surgery (AMCICO) make recommendations based in the information available at the moment, to help decide when and how to perform a spine surgery in the coronavirus pandemic. Objective: To provide the spine surgeon with the tools required and a decision path to postpone or perform a spine surgery in the COVID-19 pandemic.

La pandemia de COVID-19 ha afectado de forma significativa la forma de vida en el mundo y en México. El área de la medicina no es la excepción, ya que se requiere hacer cambios en la forma en la que valoramos y tratamos a nuestros pacientes para tratar de garantizar su seguridad, la del equipo médico y el personal de salud, las instituciones de salud y la comunidad. En este artículo exponemos las recomendaciones de la Asociación Mexicana de Cirujanos de Columna (AMCICO) para realizar una cirugía de columna durante la pandemia del nuevo coronavirus COVID-19. Objetivo: Proveer al cirujano de columna los elementos necesarios para seguir una ruta en la toma de decisiones para posponer o realizar una cirugía de columna durante la pandemia del nuevo coronavirus COVID-19.

[Results in the surgical treatment of lumbar disc hernia, report of seven years follow up]. / Resultados en el tratamiento quirúrgico de hernia discal lumbar, reporte a siete años de seguimiento.

INTRODUCTION: Low back pain by herniated disc is caused by abnormal intersomatic movement, considering this as an etiological factor of disc herniation and the surgical indication. MATERIAL AND METHODS: A prospective, descriptive, observational, longitudinal study design, in a period from January 2000 to December 2006. Initial sample of 195 patients, with inclusion criteria in 20 patients at seven years follow up. Demographic, dependent and independent variables were taken into account. Descriptive statistical analysis was conducted comparing preoperative with evolution to seven years. RESULTS: Two groups were compared: dynamic interspinous stabilization and lumbar arthroplasty, with 10 patients for each procedure. Using T and 2 test, statistical significance was observed when comparing the results of pain and Oswestry scale with parameters of imaging according to Pfirrmann pre surgical against final follow-up in patients undergoing dynamic stabilization. And for Arthroplasty was statistically meaningful comparison of results of pain with VAS (visual analogue scale) and function with Oswestry scale, with a p 0.05. CONCLUSION: With this work we can see that there was statistical significance to compare clinical outcomes of both procedures, observing a minimum percentage of complications in patients who underwent dynamic stabilization compared with arthroplasty; therefore we suggest to perform the latter only in cases in all criteria, to meet adequately to be equal to the anticipated clinical and functional outcomes.

INTRODUCCIÓN: La lumbalgia por hernia discal es provocada por el movimiento anormal intersomático, considerándose éste como factor etiológico de hernia discal, que en ocasiones es la indicación quirúrgica. MATERIAL Y MÉTODOS: Con un diseño de estudio prospectivo, descriptivo, observacional y longitudinal en un período de Enero de 2000 a Diciembre de 2006. Muestra inicial de 195 pacientes, con 20 pacientes con criterios de inclusión a los siete años de seguimiento. Se tomaron en cuenta variables demográficas, dependientes e independientes. Se realizó análisis estadístico descriptivo comparando preoperatorio con la evolución a siete años. RESULTADOS: Se englobaron los resultados en dos procedimientos: estabilización dinámica interespinosa y artroplastía, con 10 pacientes por cada procedimiento. Mediante la prueba de T y 2 se observó significancia estadística al comparar los resultados de dolor y escala de Oswestry con parámetros de imagenología según Pfirrmann prequirúrgicos contra seguimiento final en los pacientes sometidos a estabilización dinámica. Para el grupo de artroplastía fue estadísticamente significativa la comparación de resultados de dolor con EVA (escala visual análoga) y función con escala de Oswestry, con una p 0.05. CONCLUSIÓN: Con este trabajo comprobamos que hubo significancia estadística al comparar los resultados clínicos de ambos procedimientos, observamos un porcentaje mínimo de complicaciones en los pacientes a quienes se les realizó estabilización dinámica en comparación con la artroplastía; por lo tanto, sugerimos realizar esta última sólo en casos en los que se reúnan adecuadamente todos los criterios para que los resultados clínicos y funcionales sean iguales a los esperados.

Ligamentum flavum in lumbar spinal stenosis, disc herniation and degenerative spondylolisthesis. An histopathological description.

INTRODUCCIÓN: Los cambios en el ligamento flavum (LF) relacionados con la degeneración son secundarios al proceso de envejecimiento o a la inestabilidad mecánica. Estudios anteriores han indicado que LF con envejecimiento muestra pérdida de fibras elásticas y aumento del contenido de colágeno, la pérdida de elasticidad puede hacer que el LF se pliegue en el canal espinal, disminuyendo su espacio. MATERIAL Y MÉTODOS: Se incluyeron 67 pacientes operados de estenosis lumbar espinal (LSS), hernia de disco lumbar (LDH) y espondilolistesis degenerativa (LDS). Se obtuvieron muestras de LF de pacientes que tenían LSS (39), LDH (22) y LDS (6). Se examinaron especímenes con respecto a metaplasia condroide, calcificación, fragmentación de fibras de colágeno, degeneración quística, apariencia fibrilar e hipercelularidad. RESULTADOS: Los cambios histopatológicos más frecuentes fueron la hialinización y la fragmentación de las fibras de colágeno (34%), neovascularización en 40.3%, y la disposición irregular de las fibras elásticas es el cambio más frecuente con 56.7% del total de muestras. Existe una diferencia en la presencia de cambios en el LF, de acuerdo con el diagnóstico, siendo estadísticamente significativo para la fragmentación de las fibras de colágeno (p = 0.045), la degeneración quística (p = 0.001), la apariencia fibrilar (p = 0.007) y la hipercelularidad (p = 0.005) todos ellos, siendo más frecuentes en el grupo LDS. El grupo LHD presentó fragmentación de las fibras de colágeno en 45.5% (p = 0.045) y la apariencia fibrilar en 4.5% (p = 0.009). CONCLUSIONES: No hay evidencia de hipertrofia celular en los análisis histopatológicos, el engrosamiento del LF se puede ver por abultamiento del mismo, seguido de colapso del segmento de movimiento.

INTRODUCTION: Changes in ligamentum flavum (LF) related to degeneration are secondary to either the aging process or mechanical instability. Previous studies have indicated that LF with aging shows elastic fiber loss and increased collagen content, loss of elasticity may cause LF to fold into the spinal canal, which may further narrow of the canal. MATERIAL AND METHODS: A total of 67 patients operated with the surgical indications of lumbar spinal stenosis (LSS), lumbar disc herniation (LDH) and lumbar degenerative spondylolisthesis (LDS) were included. LF samples were obtained from patients who had LSS (39), LDH (22) and LDS (6). Specimens were examined with regard to chondroid metaplasia, calcification, fragmentation of collagen fibers, cystic degeneration, fibrillar appearence, and hypercellularity. RESULTS: The most frequent histopathological changes were hyalinization and fragmentation of collagen fibers occur in 34%, neovascularization in 40.3% and irregular arrangement of elastic fibers is the most prevalent change with 56.7% of the total samples. There is a difference in the presence of certain changes in the LF according to the diagnosis, being statistically significant for fragmentation of collagen fibers (p = 0.045), cystic degeneration (p = 0.001), fibrillar appearance (p = 0.007) and hypercellularity (p = 0.005) all of these, being more prevalent in LDS group. LHD group presented fragmentation of collagen fibers in 45.5% (p = 0.045) and fibrillar appearance in 4.5% (p = 0.009). CONCLUSIONS: There is not evidence of cellular hyperthophy in the histhopatological analyses, thickening of the LF can be seen by bulking of LF followed by collapse of motion segment.

Epidemiological and radiological profile of patients with degenerative scoliosis: 20 year experience at a referral institute.

BACKGROUND: Adult degenerative scoliosis is a complex three-dimensional rotational deformity, in a previously straight spine, resulting in sagittal and axial disbalance. MATERIAL AND METHODS: This retrospective study presents the casuistry of patients 40 to 80 years old with adult degenerative scoliosis who underwent surgery in a referral institute from January 1994 to December 2013. RESULTS: The prevalence was 0.087% (CI 95% 67.8-111), with a median age of 64.9 ± 9.4 years old, increased frequency in women and older adults. The prevalence of spondylolisthesis associated with degenerative scoliosis was 21%. The estimated risk for scoliosis in women was OR = 2.37 (CI 95% 1.35-4.15), while men showed OR = 0.4 (CI95% 0.24-0.73). The risk for spondylolisthesis associated to degenerative scoliosis was in men OR = 1.87. CONCLUSIONS: The prevalence in our experience is low and the sample age was higher; while gender, severity of the curve and presence of spondylolisthesis and olistesis were similar to the reviewed literature.

ANTECEDENTES: La escoliosis degenerativa del adulto es una deformidad rotacional tridimensional compleja, en una columna recta previamente, dando por resultado desequilibrio sagital y axial. MATERIAL Y MÉTODOS: Este estudio retrospectivo presenta la casuística de los pacientes de 40 a 80 años de edad con escoliosis degenerativa del adulto que experimentaron la cirugía en un instituto de referencia desde enero de 1994 a diciembre de 2013. RESULTADOS: La prevalencia fue de 0.087% (IC 95% 67.8-111), con una edad media de 64.9 ± 9.4 años, mayor frecuencia en mujeres y adultos mayores. La prevalencia de la espondilolistesis asociada a escoliosis degenerativa fue de 21%. El riesgo estimado para la escoliosis en las mujeres fue = 2.37 (IC 95% 1.35-4.15), mientras que los hombres mostraron OR = 0.4 (IC95% 0.24-0.73). El riesgo de espondilolistesis asociada a escoliosis degenerativa fue en hombres OR = 1.87. CONCLUSIONES: La prevalencia en nuestra experiencia es baja y la edad de la muestra fue mayor; mientras que el género, la gravedad de la curva y la presencia de espondilolistesis y olistesis eran similares a la literatura consultada.

Lumbar fusion with collagen type I and polyvinylpyrrolidone in combination with autograft. An experimental study in New Zealand rabbits.

INTRODUCTION: Multiple strategies have been developed looking for upgrading the consolidation rate of spine arthrodesis with autolog bone graft, but no evidence exists that adhesion with Collagen type 1 and polyvinylpyrrolidone (FibroquelMR) have application on this field. OBJECTIVE: Determine if collagen type 1 + Polyvinylpyrrolidone are effective as bone enhancer in posterolateral arthrodesis on rabbits. METHOD: Posterolateral arthrodesis in 15 New Zealand rabbits on level L5-L6 using autolog bone graft in left side (control group) and autolog bone graft + 1 ml FibroquelMR (study group) in right side of arthrodesis. Euthanasia and block resection of lumbar segment eight weeks post surgery. Radiographic analysis, manual exploration and light microscopy of fussed segments. RESULTS: Radiographic consolidation was observed in 80% in control group and 95% in study group, interleaved trabecular pattern with bone continuity and normal characteristics in 12 left sides and 14 right sides. CONCLUSION: Collagen type 1 and polyvinylpyrrolidone use is likely to have positive effect in bone consolidation process, therefore it can be recommended to use it as a bone enhancer.

INTRODUCCIÓN: Existen diversas estrategias para aumentar la tasa de consolidación de la artrodesis de columna en presencia de injerto óseo autólogo, sin aún comprobar si la adhesión de Colágena tipo I y polivinilpirrolidona (FibroquelMR) tienen aplicaciones en este campo. OBJETIVO: Determinar la efectividad de la colágena tipo I con polivinilpirrolidona como potenciador óseo en artrodesis posterolateral de conejos. MÉTODOS: Artrodesis posterolateral en 15 conejos de Nueva Zelanda L5-L6 colocando injerto autólogo del lado izquierdo (Control) e injerto autólogo + 1 ml FibroquelMR (Estudio) en el lado derecho de la artrodesis. Eutanasia con resección en bloque del segmento lumbar a las ocho semanas del postoperatorio. Análisis radiográfico, palpación manual y por microscopia de luz de los segmentos fusionados. RESULTADOS: Se observó consolidación radiográfica en 80% en grupo control y 93% en el estudio, continuidad ósea con patrón trabecular intercalado y hueso de características normales en 12 del lado izquierdo y 14 en el lado derecho. CONCLUSIONES: La utilización de Colágena tipo I y polivinilpirrolidona puede tener efectos positivos en el proceso de consolidación ósea por lo que se puede recomendar su utilización como reforzador óseo.

Lumbar fusion with collagen type I and polyvinylpyrrolidone in combination with autograft. An experimental study in New Zealand rabbits / Colágena tipo I y polivinilpirrolidona en combinación con autoinjerto para artrodesis lumbar. Estudio experimental en conejos de Nueva Zelanda

Abstract: Introduction: Multiple strategies have been developed looking for upgrading the consolidation rate of spine arthrodesis with autolog bone graft, but no evidence exists that adhesion with Collagen type 1 and polyvinylpyrrolidone (FibroquelMR) have application on this field. Objective: Determine if collagen type 1 + Polyvinylpyrrolidone are effective as bone enhancer in posterolateral arthrodesis on rabbits. Method: Posterolateral arthrodesis in 15 New Zealand rabbits on level L5-L6 using autolog bone graft in left side (control group) and autolog bone graft + 1 ml FibroquelMR (study group) in right side of arthrodesis. Euthanasia and block resection of lumbar segment eight weeks post surgery. Radiographic analysis, manual exploration and light microscopy of fussed segments. Results: Radiographic consolidation was observed in 80% in control group and 95% in study group, interleaved trabecular pattern with bone continuity and normal characteristics in 12 left sides and 14 right sides. Conclusion: Collagen type 1 and polyvinylpyrrolidone use is likely to have positive effect in bone consolidation process, therefore it can be recommended to use it as a bone enhancer.

Resumen: Introducción: Existen diversas estrategias para aumentar la tasa de consolidación de la artrodesis de columna en presencia de injerto óseo autólogo, sin aún comprobar si la adhesión de Colágena tipo I y polivinilpirrolidona (FibroquelMR) tienen aplicaciones en este campo. Objetivo: Determinar la efectividad de la colágena tipo I con polivinilpirrolidona como potenciador óseo en artrodesis posterolateral de conejos. Métodos: Artrodesis posterolateral en 15 conejos de Nueva Zelanda L5-L6 colocando injerto autólogo del lado izquierdo (Control) e injerto autólogo + 1 ml FibroquelMR (Estudio) en el lado derecho de la artrodesis. Eutanasia con resección en bloque del segmento lumbar a las ocho semanas del postoperatorio. Análisis radiográfico, palpación manual y por microscopia de luz de los segmentos fusionados. Resultados: Se observó consolidación radiográfica en 80% en grupo control y 93% en el estudio, continuidad ósea con patrón trabecular intercalado y hueso de características normales en 12 del lado izquierdo y 14 en el lado derecho. Conclusiones: La utilización de Colágena tipo I y polivinilpirrolidona puede tener efectos positivos en el proceso de consolidación ósea por lo que se puede recomendar su utilización como reforzador óseo.

Low functional robustness in mesial temporal lobe epilepsy.

OBJECTIVES: Brain functional topology was investigated in patients with mesial temporal lobe epilepsy (mTLE) by means of graph theory measures in two differentially defined graphs. Measures of segregation, integration, and centrality were compared between subjects with mTLE and healthy controls (HC). METHODS: Eleven subjects with mTLE (age 36.5±10.9years) and 15 age-matched HC (age 36.8±14.0years) participated in this study. Both anatomically and functionally defined adjacency matrices were used to investigate the measures. Binary undirected graphs were constructed to study network segregation by calculating global clustering and modularity, and network integration by calculating local and global efficiency. Node degree and participation coefficient were also computed in order to investigate network hubs and their classification into provincial or connector hubs. Measures were investigated in a range of low to medium graph density. RESULTS: The group of patients presented lower global segregation than HC while showing higher global but lower local integration. They also failed to engage regions that comprise the default-mode network (DMN) as hubs such as bilateral medial frontal regions, PCC/precuneus complex, and right inferior parietal lobule, which were present in controls. Furthermore, the cerebellum in subjects with mTLE seemed to be playing a major role in the integration of their functional networks, which was evident through the engagement of cerebellar regions as connector hubs. CONCLUSIONS: Functional networks in subjects with mTLE presented both global and local abnormalities compared to healthy subjects. Specifically, there was significant separation between groups, with lower global segregation and slightly higher global integration observed in patients. This could be indicative of a network that is working as a whole instead of in segregated or specialized communities, which could translate into a less robust network and more prone to disruption in the group with epilepsy. Furthermore, functional irregularities were also observed in the group of patients in terms of the engagement of cerebellar regions as hubs while failing to engage DMN-related areas as major hubs in the network. The use of two differentially defined graphs synergistically contributed to findings.

[Degenerative adult scoliosis]. / Escoliosis degenerativa del adulto.

Adult scoliosis is a complex three-dimensional rotational deformity of the spine, resulting from the progressive degeneration of the vertebral elements in middle age, in a previously straight spine; a Cobb angle greater than 10° in the coronal plane, which also alters the sagittal and axial planes. It originates an asymmetrical degenerative disc and facet joint, creating asymmetrical loads and subsequently deformity. The main symptom is axial, radicular pain and neurological deficit. Conservative treatment includes drugs and physical therapy. The epidural injections and facet for selectively blocking nerve roots improves short-term pain. Surgical treatment is reserved for patients with intractable pain, radiculopathy and/ or neurological deficits. There is no consensus for surgical indications, however, it must have a clear understanding of the symptoms and clinical signs. The goal of surgery is to decompress neural elements with restoration, modification of the three-dimensional shape deformity and stabilize the coronal and sagittal balance.

Studies on the regulation of X-prolyl dipeptidyl aminopeptidase activity.

The specific activity of X-prolyl-dipeptidyl aminopeptidase in Saccharomyces cerevisiae grown on glucose-containing medium remains constant during exponential growth and increases less than twofold when cells reach the stationary phase. In cells harvested from exponential growth on glucose-containing medium the specific activity of the enzyme is found to be 20-30% lower than the specific activity observed in media without glucose, containing acetate or ethanol as the carbon source. X-Prolyl-dipeptidyl aminopeptidase is not inactivated after the addition of glucose to stationary phase cells. Growth of the yeast on poor nitrogen sources or under nitrogen-starvation results in a three- to fourfold increase in the level of the enzyme.

Effects of standing position on spontaneous uterine contractility and other aspects of labor.

The aim of this paper has been to compare the uterine contractility, pain produced by contractions and comfort of the patients between standing and supine position. The study has been performed in twenty normal nulliparae who were changed from supine to standing position and viceversa at intervals of approximately thirty minutes. Intrauterine pressure and fetal heart rate were continuously monitored. Cervial dilatation was evaluated every thirty minutes. No medication was given to the patients. They were asked to assess the pain produced by uterine contractions in each one of both positions and which was the more comfortable. It has been found: 1. That the intensity of contractions was significantly higher in fifteen out of the twenty patients in standing position. 2. Frequency of contractions diminished significantly in one third of the patients. 3. Uterine activity increased significantly in half of them. 4. Consistently, less pain accompanied uterine contractions in standing position. 5. Patients reported more comfort in this position. The average duration of labor was 3 hrs 55 min. This duration is short, compared with standard clinical experience and with published data. No complications occurred, by the use of standing position during labor, on the mother or fetus. The physiological mechanisms responsible for the above mentioned effects of standing position are unknown. It is condluced that there are no clear arguments against the use of standing position during labor and that this position should be used more frequently in clinical obstetrics, provided obstetrical conditions are similar to those reported in this paper.

[Therapy of secondary effects produced by anovulatory agents]. / Terapéutica de los efectos secundarios producidos por anovulatorios

PIP: The most common side effects produced by anovulatory contraceptives are similar to those experienced in the 1st months of pregnancy, e.g., weight gain, nausea, and fatigue. In an effort to determine to what extent such side effects were attributable to the medication and to what extent they were psychological, KN-1055 was administered to 43 women taking anovulatory contraceptives. 10 began taking both substances simultaneously; none of them had any side effects. The remaining 33 were selected from a group of 140 already taking anovulatories because they were experiencing side effects. Experience of side effects was not found to be related to either age or parity. Side effects were eliminated within 14 days of administration of 2 tablets daily of KN-10055 in 15 cases, which was thought to be a very good result; within 28 days in 13 cases, a good result; and in more than 28 days in 3 cases. In 2 cases KN-10055 did not eliminate side effects; such effects were therefore thought to be of psychological origin. Treatment during 2 cycles was sufficient, though KN-10055 can be taken for as many cycles as necessary.^ieng