Mexican Multicenter Experience of Metastatic Spinal Disease.

Background Spinal metastatic disease is a silent progressive cancer complication with an increasing prevalence worldwide. The spine is the third most common site where solid tumors metastasize. Complications involved in spinal metastasis include root or spinal cord compression, progressing to a declining quality of life as patient autonomy reduces and pain increases. The main objective of this study is to report the incidence of patients and typology of spinal metastases in three reference centers in Mexico. Methodology Retrospective cohorts of patients diagnosed with spinal metastases from January 2010 to February 2017 at the National Cancer Institute, National Rehabilitation Institute, and the Traumatology and Orthopedics Hospital "Lomas Verdes" in Mexico City were analyzed. Results A total of 326 patients (56% males) with spinal metastases were reported. The mean age was 58.06 ± 14.05 years. The main sources of spinal metastases were tumors of unknown origin in 53 (16.25%) cases, breast cancer in 67 (20.5%) cases, prostate cancer in 59 (18%) cases, myeloma in 24 (7.4%) cases, and lung cancer in 23 (7.1%) cases. Conclusions The data obtained in this analysis delivers an updated standpoint on Mexico, providing the opportunity to distinguish the current data from global references. Collecting more epidemiological information for better recording of cancer and its associated complications, as well as further studies on them, is necessary.

Single Dose of Tranexamic Acid Effectively Reduces Blood Loss in Patients Undergoing Spine Surgery: A Prospective Randomized Controlled Trial.

OBJECTIVE: To evaluate the efficacy of oral administration of tranexamic acid (TXA) in spine surgery to achieve blood loss reduction. METHODS: Sixty patients undergoing major surgery of the spine were randomly assigned into 2 groups. Group 1 was assigned as the control group and the other group comprised patients who received oral administration of TXA 2 hours before surgery. Outcome measures included intraoperative blood loss, postoperative blood loss, hematologic parameters, blood transfusion needed, and surgical complications. RESULTS: Sixty patients linked up with the inclusion criteria. Intraoperative blood loss was significantly lower in the TXA oral group than in the control group; total blood loss in the TXA group was 930.66 ± 614 mL, which was lower than in the control group, with 1075.66 ± 956.11 mL. The mean reduction of hemoglobin was almost the same in both groups. Similarly, the total transfusion package received was lower, and the number of complications and length of stay were akin in both groups. A logistic regression model was performed with patients who had blood loss >1000 mL and surgery time >230 minutes. This result was related to the risk of bleeding, with an odds ratio of 1.31, 95% confidence interval, 1.004-1.023, P = 0.004, independent of the group. CONCLUSIONS: Oral TXA is as an effective measure for reducing total blood loss among patients undergoing elective spine surgery.

Women in Neurosurgery: First Neurosurgeon in Latin America and Current Mexican Leaders.

BACKGROUND: History has taught us that Mexican culture has been largely supported by women, despite gender prejudice from the society. Neurosurgery has not been the exception. Therefore, we investigated the challenges and influence of female neurosurgeons in Mexico. METHODS: We conducted a review of the literature and an analysis of the internal database of the Mexican Society of Neurological Surgery focusing on 3 topics: 1) the historical presence of women and gender inequality in Mexico; 2) the life and legacy of the woman who became the first neurosurgeon in Mexico and in Latin America; and 3) the participation of women in neurosurgery in the past 3 decades. RESULTS: In Latin America, the first woman in neurosurgery was María Cristina García-Sancho, who completed her neurosurgical training in 1951. Currently, women represent 6.2% of the total members of the Mexican Society of Neurological Surgery (MSNS). This percentage is still low, although data collected in this study suggest that it might increase in the next few years because 16.7% of Board Directors of the MSNS are women, the next elected president is a female neurosurgeon, and 14.5% of neurosurgery residents are women. CONCLUSIONS: Although a steady increase has occurred of women in neurosurgery in Mexico, there is still work to do, especially to overcome the barriers related to the old assumptions of the cultural and social roles of women.

Posterior Grade 4 Osteotomy With Vertebral Shortening Is Effective for the Treatment of Kyphosis Associated With Vertebral Discitis/Osteomyelitis.

BACKGROUND: In the retrospective study of a prospectively maintained database, we present a case series of patients with kyphotic deformity secondary to spinal infection treated using a posterior-only approach with 3-column shortening and posterior instrumentation. METHODS: This is a case series of patients presenting with postural deformity and sagittal imbalance treated consecutively by 1 surgeon between 2012 and 2014. Clinical assessments and radiographic evaluations were made preoperatively and at 12- and 24-month postoperative follow-ups. All patients underwent computed tomography 24 months after surgery to evaluate spinal fusion. RESULTS: The study included 5 patients with a mean age of 50 years (range, 32-60 years). Three patients had comorbidities. Three patients were classified as American Spinal Injury Association (ASIA) grade C and were not ambulatory; 2 were ASIA grade D. At follow-up, all patients were ambulatory and classified as ASIA grade E. Kyphosis was corrected from a preoperative mean of 32° (range, 15°-58°) to 10° (range, 1°-42°) at the 2-year follow-up. A mean improvement of 22° and 75% reduction in kyphosis was obtained with fixation 2 levels above and below the lesion. Interbody fusion was observed in all patients. No major complications occurred during surgery. CONCLUSIONS: Posterior grade 4 osteotomy with vertebral shortening can be performed safely in patients with kyphosis associated with vertebral discitis/osteomyelitis in the thoracolumbar region. The single approach allowed the surgeon to debride the infection, correct the kyphosis, decompress the spinal canal, and stabilize the spine. LEVEL OF EVIDENCE: 4.

Biomechanical behavior of bone tissue in spine instrumentation.

BACKGROUND: The mechanical fixation of the spine in patients with osteoporotic vertebral degeneration is a challenge for surgeons, the vertebrae selected to insert the screws may fail, endangering health and even patient's life. OBJECTIVE: The objective of the study was to study the effect of the variation of the bone density in the bone-screw interface from a three-dimensional model of the lumbar section. MATERIALS AND METHODS: The finite element method was used to model the behavior of the lumbar vertebral section when applying compression loads. RESULTS: The stresses between 2 and 3 MPa were located on the contact surface with the screw, both in the vertebral body and in the apophysis, being slightly higher in the vertebral body. CONCLUSIONS: Regardless of bone density, the contact zones between the screws are susceptible to bone tissue failure. The posterior half of the vertebral body was the most sensitive to high values of stress, while in the areas furthest from the axis of the screw stress tended to their minimum.

INTRODUCCIÓN: La fijación mecánica de la columna en pacientes con degeneración vertebral osteoporótica es un reto para los cirujanos, pues las vértebras seleccionadas para insertar los tornillos pueden fallar, poniendo en peligro la salud y la vida del paciente. OBJETIVO: Estudiar el efecto de la variación de la densidad ósea en la interfase hueso-tornillo, a partir de un modelo tridimensional de la sección lumbar. MATERIALES Y MÉTODOS: Se emplea el método de los elementos finitos para modelar el comportamiento de la sección vertebral lumbar al aplicar cargas de compresión. RESULTADOS: Los esfuerzos entre 2 y 3 MPa se ubicaron en la superficie de contacto con el tornillo, tanto en el cuerpo vertebral como en la apófisis, siendo ligeramente superiores en el cuerpo vertebral. CONCLUSIONES: Independientemente de la densidad ósea, las zonas de contacto entre el tornillo son susceptibles al fallo del tejido óseo, debido a que están próximos al esfuerzo de fallo óseo de 2.37 ± 1.14 MPa reportado en la literatura. La mitad posterior del cuerpo vertebral fue la más sensible a sufrir valores altos de esfuerzos, mientras que en las zonas más alejadas del eje del tornillo los esfuerzos tendieron a su magnitud mínima.

[Results to 4-year follow-up of the treatment of the cervical stenosis by corpectomy, titanium mesh cage and anterior plate fixation]. / Resultados a 4 años de seguimiento del tratamiento del conducto cervical estrecho mediante corpectomía, malla de titanio y fijación anterior con placa.

BACKGROUND: Cervical spondylotic myelopathy is caused by cervical stenosis. Several techniques have been described for the treatment of multilevel disease, such as the anterior corpectomy with titanium mesh cage and anterior cervical plate placement, which has the advantage of performing a wider decompression and using the same bone as graft. However, it has caused controversy since the collapse of the mesh cage continues being a major limitation of this procedure. MATERIAL AND METHOD: A prospective 4-year follow-up study was conducted in 7 patients diagnosed with cervical stenosis, who were treated surgically by one level corpectomy with titanium mesh cage and anterior cervical plate placement, evaluating them by radiographs and clinical scales. RESULTS: 7 patients, 5 women and 2 males were studied. The most common level was C5 corpectomy (n=4). The Neck Disability Index (NDI) preoperative average was 30.01±24.32 and 4-year postoperative 16.90±32.05, with p=0.801. The preoperative and 4-year postoperative Nürick was 3.28± 48 and 3.14±1.21 respectively, with p=0.766. Preoperative lordosis was 14.42±8.03 and 4-year postoperative 17±11.67 degrees, with p=0.660. The immediate postoperative and 4-year postoperative subsidence was 2.69±2.8 and 6.11±1.61 millimeters respectively, with p=0.0001. CONCLUSIONS: Despite the small sample, the subsidence of the mesh cage is common in this procedure. No statistically significant changes were observed in the lordosis or Nürick scale and NDI.

[Profile of the patient with failed back surgery syndrome in the National Institute of Rehabilitation. Comparative analysis]. / Perfil del paciente con síndrome de columna multioperada en el Instituto Nacional de Rehabilitación. Análisis comparativo.

BACKGROUND: Failed back surgery syndrome is a complication of spine surgery that leads to chronic pain and disability, often with disastrous emotional consequences to the patient. AIM: To compare the profile of patients whose first surgery was performed in our hospital versus a group that underwent first spine surgery in a different centre. METHODS: Retrospective study with 65 patients; 18 formed group I (first spine surgery performed in our institution), and 47 patients in group II (first surgery performed in another hospital). Background, demographic, clinical features and functional status were compared. In group I the majority of the cases had a previous diagnosis of lumbar stenosis (group I 44.4% vs group II 25.5% p = 0.22), whereas disk herniation was the main diagnosis in group II (group I 22.2% vs group II 61.7% p = 0.001). The main cause of the syndrome in group I was technical error during surgery (61.1%), while in group II this cause represented only 6.3% (p=.001). Among the patients of this latter group, misdiagnosis was highly prevalent (57.4%), against no cases in group I (p=.001). The preoperative functional status between both groups and their recovery in the immediate postoperative period was similar (p = 0.68). CONCLUSIONS: This study suggests that the diagnostic and treatment standards are different between healthcare centres, specifically between academic centres vs. private practice.

3D patient-specific model of the tibia from CT for orthopedic use.

OBJECTIVES: 3D patient-specific model of the tibia is used to determine the torque needed to initialize the tibial torsion correction. METHODS: The finite elements method is used in the biomechanical modeling of tibia. The geometric model of the tibia is obtained from CT images. The tibia is modeled as an anisotropic material with non-homogeneous mechanical properties. CONCLUSIONS: The maximum stress is located in the shaft of tibia diaphysis. With both meshes are obtained similar results of stresses and displacements. For this patient-specific model, the torque must be greater than 30 Nm to initialize the correction of tibial torsion deformity.

[Transpedicular dynamics stabilization in the treatment of lumbar stenosis. Fourth years follow-up]. / Estabilización dinámica transpedicular en el tratamiento del conducto lumbar estrecho. Seguimiento cuatro años.

INTRODUCTION: We need to evaluate the efficacy and safety of the use of dynamic fixation in patients with narrow lumbar through comparing the assessment of two years with 4 years of follow-up. METHODS: Prospective, longitudinal, autocontrol deliberately and sequential intervention, in lumbar stenosis patients who made treatment with dynamic stabilization posterior type Acuflex. An evaluation of four of final follow-up. RESULTS: 18 patients who completed follow-up two years results as a basis for comparison: 18 patients, 14 female and 4 male, average age 44.05 years. Pain evaluated with numerical visual scale was found in the lower back at 24 months in an average of 2.84 and 48 months in 3.26. We measured the functional level of Oswestry at two years to be 24% and at four years 22.44%, with a p = 0.373. In the magnetic resonance for classification of patients 15 Pfirrmann without changes and three with increase of a degree. According to patients 2 Modic changes one of type 0 to type III and another to type I. We have observed that five patients have required second surgery for removal of material findings. CONCLUSIONS: There is no change between 2 and 4 years in the scale of Oswestry and pain with visual numerical scale functionality. The average height in discs had change with statistical significance, in the comparative period. The intervertebral discs had changes in 3 patients with direct relationship between scale of Pfirrmann and Modic. The rest of patients keep rehydration and normal disc height.

[Use of the PEEK cage in cervical spondylosis treatment]. / Uso de caja de PEEK (Poli-ether-ether-ketona) parael tratamiento de la espondilosis cervical.

BACKGROUND: Decompression and fusion with autograft is the gold standard technique in the treatment of cervical canal strait. Using PEEK cages or boxes of non-absorbable polymer with elasticity similar to bone, radiolucent, reduces morbidity and same degree of fusion. METHODS: A case series, prospective, longitudinal, deliberate intervention, evaluation panel before and after 2 years follow-up. Discectomy and PEEK housing placement with autologous graft. Arthrodesis were evaluated, cervical lordosis, intervertebral space height, pain evaluated with Visual Analogue Scale, Neck Disability Index, operative time, intraoperative bleeding, hospital stay and complications. Statistical analysis with t Sudent, Wilcoxon and Fisher's exact text. RESULTS: Of 17 patients studied, 9 (53%) were female. Average age 62 years. The most affected level was C5-6, C6-7 with 5 patients. Melting was found at 100%. There was no sag or migration of the box, space height was conserved, but segmental lordosis was not retained. Clinical improvement in all patients as well as disability index was seen. Bleeding was on average 187 mL. CONCLUSION: With regard to symptom improvement, conservation of interspace height and back, no segmental lordosis conservation and fusion using PEEK box is consistent with the literature. We suggest using anterior plate to maintain cervical lordosis. We found a melt index of 100%. We found clinical improvement of symptoms, pain and disability, and a global loss of cervical lordosis.

Antecedentes: la descompresión y artrodesis con auto-injerto es el patrón de referencia para el tratamiento del conducto cervical estrecho. El uso de cajas de PEEK polímero no reabsorbible, con elasticidad similar al hueso, radiolúcido, y mismo grado de fusión reduce la morbilidad. aterial y métodos: estudio de serie de casos, prospectivo, longitudinal, de intervención deliberada, evaluación en grupol antes y después, seguimiento a dos años. Discoidectomía y colocación de caja de PEEK con injerto autólogo. Se evaluaron artrodesis, lordosis cervical, altura del espacio intervertebral, dolor mediante escala visual análoga, índice de discapacidad cervical, tiempo quirúrgico, sangrado transoperatorio, estancia intrahospitalaria y complicaciones. Análisis estadístico con t de Student, Wilcoxon y exacta de Fisher. Resultados: de 17 pacientes estudiados, 9 (53%) eran del sexo femenino. La edad promedio 62 años. Sangrado promedio de 187 mL. El nivel más afectado fue C5-C6, C6-C7 en cinco pacientes. Se encontró fusión al 100% sin hundimiento ni migración de la caja, altura del espacio conservada, pero no se conservó la lordosis segmentaria. Mejoría clínica en todos los pacientes, y del índice de discapacidad. Conclusión: la disminución de los síntomas, la conservación de la altura del espacio anterior y posterior, la no conservación de la lordosis segmentaria y la fusión con caja de PEEK fueron congruentes con lo reportado en la bibliografía. Se sugiere utilizar la placa anterior para mantener la lordosis cervical. El índice de fusión encontrado fue de 100%, con disminución de los síntomas de dolor y discapacidad. Pérdida de lordosis cervical global.

Resultados de biopsia guiada por tomografía axial computarizada en el síndrome de destrucción vertebral, evaluados en dos instituciones distintas / Resultados de biópsia guiada por tomografia computadorizada axial na síndrome de destruição vertebral, avaliados em duas instituições distintas / Results of computerized axial tomography-guided biopsy in the vertebral destruction syndrome, evaluated at two different institutions

OBJETIVO: Comparar resultados de biopsias vertebrales guiadas por tomografía axial computarizada, reportados por dos servicios de Anatomía Patológica distintos en pacientes con síndrome de destrucción vertebral para confirmar confiabilidad y utilidad en el diagnóstico. MÉTODOS: Se obtuvieron muestras de tejido de 21 pacientes en el periodo comprendido del 1 de marzo al 15 de julio del 2011 con el diagnóstico del síndrome de destrucción vertebral y a quienes se les realizó biopsia guiada por tomografía axial computarizada. Las muestras se enviaron en forma cegada a dos servicios de patología distintos. Los resultados fueron analizados con el método de comparación de dos proporciones. RESULTADOS: 14 pacientes fueron del género masculino (67%) y 7 del femenino (23%), edades de 28-82, con afección principalmente lumbar (48%) y torácica (38%); afectados en una vértebra en 62%, en dos en un 33% y en 3 o más niveles en 5%. Las vértebras más afectadas fueron L1, L2 y L3 (12/30 [40%]), T4 (3/30 [10%]) y T9 (3/30 [10%]). Los resultados se agruparon en categorías: 1. Osteomielitis (9/21 [43%]), 2. Tumores (7/21 [33%]), 3. Metástasis (3/21 [14%]), 4. Tejido normal (2/21 [10%]), 5. Inflamación (0/21 [0%]), 6. Muestra inadecuada (0/21 [0%]), 7. Mal de Pott (0/21 [0%]). CONCLUSIONES: De acuerdo a los valores de Z obtenidos mediante la prueba de comparación de dos proporciones no se encontró diferencia significativa entre los resultados reportados por dos los dos servicios de patología en el síndrome estudiado, determinándose que esta parte del proceso es confiable y útil en un 90%.

OBJETIVO: Comparar resultados de biópsias vertebrais guiadas por tomografia axial computadorizada, relatados por dois serviços de Anatomia Patológica distintos em pacientes com síndrome de destruição vertebral para confirmar a confiabilidade e a utilidade no diagnóstico. MÉTODOS: Foram obtidas amostras de tecido de 21 pacientes no período de 1 de março a 15 de julho de 2011, com diagnóstico de síndrome de destruição vertebral, que foram submetidos a biópsia guiada por tomografia axial computadorizada. As amostras foram enviadas de modo cego a dois serviços de patologia distintos. Os resultados foram analisados pelo método de comparação de duas proporções. RESULTADOS: 14 pacientes eram do sexo masculino (67%) e 7 do feminino (23%), com idades entre 28 e 82 e afecção predominantemente lombar (48%) e torácica (38%); 62% tinham comprometimento em uma vértebra, 33% em duas e 5% em três ou mais níveis. As vértebras mais afetadas foram L1, L2 e L3 (12/30 [40%]), T4 (3/30 [10%]) e T9 (3/30 [10%]). Os resultados foram agrupados em categorias: 1. Osteomielite (9/21 [43%]), 2. Tumores (7/21 [33%]), 3. Metástases (3/21 [14%]), 4. Tecido normal (2/21 [10%]), 5. Inflamação (0/21 [0%]), 6. Amostra inadequada (0/21 [0%]), 7. Mal de Pott (0/21 [0%]). CONCLUSÕES: De acordo com os valores de Z obtidos pela prova de comparação de duas proporções, não se encontrou diferença significante entre os resultados relatados pelos dois serviços de patologia na síndrome estudada, ficando determinado que essa parte do processo tem confiabilidade e utilidade de 90%.

OBJECTIVE: To compare results of vertebral biopsy guided by computerized axial tomography scan, reported by two different Departments of Pathology in patients with vertebral destruction syndrome to confirm the reliability and utility in the diagnosis. METHODS: Tissue samples from 21 patients were obtained March 1 to July 15, 2011, with a diagnosis of the vertebral destruction syndrome and who underwent computerized axial tomography-guided biopsy. The samples were blindly sent to two different pathology services. The results were analyzed using the two-proportion z-test. RESULTS: 14 patients were male (67%) and 7 females (23%), aged between 28 and 82, with condition predominantly lumbar (48%) and thoracic (38%); 62% had one vertebra affected, 33% ha two and 5% had three or more levels involved. The most affected vertebrae were L1, L2 and L3 (12/30 [40%]) and T9 (3/30 [10%]). The results were grouped into categories: 1. Osteomyelitis (9/21 [43%]), 2. Tumors (7/21 [33%]), 3. Metastases (3/21 [14%]), 4. Normal tissue (2/21 [10%]), 5. Inflammation (0/21 [0%]), 6. Inadequate sample (0/21 [0%]), 7. Pott's disease (0/21 [0%]). CONCLUSIONS: According to the values obtained by the two-proportion z-test, there was no significant difference between the results reported by the two departments of pathology for the syndrome studied, being determined that this part of the process has reliability and usefulness of 90%.

Evaluacion de la biopsia transpedicular guiada por TAC / Avaliação da biópsia transpedicular guiada por TC / Evaluation of transpedicular percutaneous biopsy guided by CT

OBJETIVO: Valorar la utilidad de la biopsia transpedicular percutánea guiada por Tomografía Axial Computarizada en conjunto con la sistematización de estudios como pruebas diagnósticas de la etiología de la destrucción vertebral. MÉTODOS: Estudio de serie de casos prospectivo transversal de 21 pacientes a los que se les realizó biopsia transpedicular percutánea guiada por Tomografía Axial Computarizada y estudios de laboratorio y gabinete de marzo a julio del 2011, para evaluar su utilidad en el diagnóstico de destrucción vertebral. RESULTADOS: Fueron 21 pacientes, 14 hombres y 7 mujeres, con edad media de 59,2 años, cuyos niveles más afectados estuvieron en L1, L2 y L3. El reporte de la biopsia tuvo una precisión diagnóstica del 90,4%. En 2 casos se realizó correlación clínica entre biopsia y sistematización de estudios para obtener el diagnóstico. CONCLUSIÓN: La biopsia guiada por Tomografía Axial Computarizada es una técnica sencilla, útil, de bajo costo y eficaz en el estudio de la destrucción vertebral; la sistematización de estudios permite corroborar el diagnóstico de la biopsia.

OBJETIVO: Avaliar a utilidade da biópsia transpedicular percutânea guiada por tomografia axial computadorizada em conjunto com a sistematização de estudos, como exames diagnósticos da etiologia da destruição vertebral. MÉTODOS: Estudo de série de casos, prospectivo e transversal de 21 pacientes submetidos à biópsia transpedicular percutânea guiada por tomografia axial computadorizada e exames laboratoriais e radiológicos, de março a julho de 2011, para avaliar sua utilidade no diagnóstico de destruição vertebral. RESULTADOS: Foram analisados 21 pacientes, 14 homens e 7 mulheres, com média de idade de 59,2 anos, cujos níveis mais afetados foram L1, L2 e L3. O laudo da biópsia teve precisão diagnóstica de 90,4%. Em dois casos, realizou-se a correlação clínica entre biópsia e sistematização de exames para obter o diagnóstico. CONCLUSÃO: A biópsia guiada por tomografia axial computadorizada é uma técnica simples, útil, de baixo custo e eficaz para o estudo da destruição vertebral; a sistematização de estudos permite corroborar o diagnóstico da biópsia.

OBJECTIVE: To evaluate the usefulness of percutaneous transpedicular biopsy guided by CT together with systematic studies such as diagnostic tests of the etiology of vertebral destruction. METHODS: Case series, prospective and crossover study of 21 patients who underwent percutaneous transpedicular biopsy guided by CT and laboratory tests and radiological studies from March to July 2011, to evaluate its usefulness in the diagnosis of vertebral destruction. RESULTS: We analyzed 21 patients, 14 men and 7 women, mean age 59.2 years, whose most affected levels were L1, L2, and L3. The biopsy report had diagnostic accuracy of 90.4%. In 2 patients the clinical correlation between biopsy and systematization of diagnostic studies was carried out. CONCLUSION: CT-guided biopsy is a simple, useful, inexpensive, and effective technique for the study of vertebral destruction; the systematic studies allow us to corroborate the diagnosis made by biopsy.

Traumatic posterior L4-L5 fracture dislocation of the lumbar spine: a case report.

Study Design Case report. Objective The diagnosis and surgical management of a patient with traumatic bilateral posterior dislocation of L4-L5 is presented with a thorough review of the existing literature. Summary of Background Data Traumatic dislocation of L4-L5 has been reported in the English literature in only five cases; of these, only two were retrolisthesis. Methods A 20-year-old patient was involved in a high-energy vehicular accident and presented with back pain and inability to ambulate. Neurological assessment showed motor strength grade 2/5 in the proximal lower-extremity muscle groups (L1-L3 myotomes) and 0/5 strength distally (L4-S1 myotomes); in addition, incontinence of sphincters was found. X-rays and computed tomography (CT) scan revealed a three-column ligamentous injury with posterior fracture-dislocation of the L4 vertebral body with complete posterior displacement of L4 to L5 vertebral body. The patient underwent posterior approach with reduction, transpedicular fixation, and posterolateral fusion with autologous bone graft. Results At 1-year follow-up, the patient had recovered muscular strength in proximal lower-extremities muscle groups, sphincter function had fully recovered, and he was able to ambulate with crutches. There was no recovery of distal extremity sensorimotor function. Plain radiograph and CT scan showed good alignment and progressive maturation of his fusion procedure. Conclusion Traumatic retrolisthesis of L4-L5 is a high-energy unstable fracture; reduction of the dislocation is challenging because of the heavy forces acting in the lower lumbar spine. Instrumented fusion restores alignment and maintains segmental stability.

Posterior dynamic stabilization of the lumbar spine with the Accuflex rod system as a stand-alone device: experience in 20 patients with 2-year follow-up.

Decompression surgery for lumbar spinal stenosis is a common procedure. After surgery, segmental instability sometimes occurs, therefore, different methods for restabilization have been developed. Dynamic stabilization systems have been designed to improve segmental stability. In this study, clinical results of patients with lumbar spinal stenosis that underwent decompression and stabilization with the Accuflex dynamic system are presented; clinical, radiographic, and magnetic resonance imaging (MRI) findings are fully described. Improvements in all clinical measurements, including visual analog scale for back and leg pain, Oswestry disability index, and SF-36 health status survey were noticed. At a 2-year follow-up, 22.22% of patients required hardware removal due to fatigue while in 83% of them no progression of disk degeneration was observed after implantation of the Accuflex system. Additionally, as demonstrated by the MRI images at follow up, three patients (16%) showed disk rehydration with one grade higher on the Pfirmann classification. Although a relatively high hardware failure was observed (22.22%), the use of the dynamic stabilization system Accuflex posterior to decompression procedures, showed clinical benefits and stopped the degenerative process in 83% the patients.

Resonancia magnética nuclear en el postoperatorio de discectomía lumbar en pacientes asintomáticos y con síndrome de cirugía lumbar fallida / Ressonância nuclear magnética no pós-operatório da discectomia lombar em pacientes assintomáticos e com síndrome de cirurgia lombar falida / Nuclear magnetic resonance in postoperative lumbar discectomy in asymptomatic patients and with failed back surgery syndrome

OBJETIVO: analizar los cambios posquirúrgicos en pacientes sometidos a discectomía lumbar, tanto en pacientes cuya evolución ha sido satisfactoria, como en aquellos con "Síndrome de Cirugía Lumbar Fallida", enfatizando el justo valor que la resonancia magnética nuclear tiene. MÉTODOS: el universo de trabajo está constituido por dos grupos: Grupo I, cinco pacientes con evolución satisfactoria, asintomáticos; y Grupo II con diez pacientes con resultados considerados no satisfactorios y/o Síndrome Fallido Lumbar. Se analizaron los resultados obtenidos en la imagen de resonancia magnética nuclear, emitiendo un diagnóstico con evaluación externa sin conocimiento del estado clínico de los pacientes. También se realizó la correlación con el estado clínico en ambos los grupos. RESULTADOS: las manifestaciones clínicas preoperatorias tuvieron una distribución muy similar. En ninguno de los dos grupos se reportaron complicaciones transoperatórias. En todos se estudió por histopatología y se reportó disco degenerado o hialinizado. En el Grupo I, no se encontró imagen de alguna anomalía a pesar de su estado clínico. En todos los pacientes se encontraron datos de fibrosis posquirúrgica; en cuatro casos, disco residual con compresión radicular en los cinco pacientes. En el Grupo II, sólo en ocho pacientes, la resonancia magnética nuclear demostró algún hallazgo anormal. Los hallazgos anormales fueron: fibrosis posquirúrgica en cinco casos (50 por ciento), disco residual en tres casos (30 por ciento) y datos de compresión radicular en seis de los casos (60 por ciento). CONCLUSIÓN: no hay congruencia entre los hallazgos de resonancia magnética nuclear y la clínica, en pacientes postoperados de discectomía lumbar con evolución satisfactoria, hasta el momento, asintomáticos. La resonancia magnética nuclear no es confiable en estos pacientes.

OBJETIVO: analisar as mudanças pós-cirúrgicas nos pacientes submetidos à discectomia lombar em pacientes com evolução satisfatória, assim como naqueles com "Síndrome de Cirurgia Falida", dando ênfase ao justo valor que a ressonância nuclear magnética tem. MÉTODOS: o universo do trabalho esta constituído por dois grupos, Grupo I com cinco pacientes com evolução satisfatória, assintomáticos. O Grupo II possui dez pacientes com resultados considerados não-satisfatórios e/ou "Síndrome Falida Lombar". Analisaram-se os resultados obtidos na imagem da ressonância nuclear magnética, emitindo um diagnóstico com avaliação externa sem conhecimento do estado clínico dos pacientes, e realizou-se uma correlação com o estado clínico de ambos os grupos. RESULTADOS: as manifestações clínicas pré-operatórias tiveram uma distribuição muito similar. Em nenhum dos grupos se reportaram complicações transoperatórias. Em todos os grupos, foi feito o estudo histopatológico e foi informado o disco degenerado ou hialinizado. No Grupo I, não foi encontrada imagem de alguma anomalia apesar de seu estado clínico. Em todos os pacientes foram encontrados dados de fibroses pós-cirúrgica, em quatro casos, disco residual, com compressão radicular nos cinco pacientes. No Grupo II, só foi possível encontrar em oito pacientes, e a ressonância nuclear magnética demonstrou algum achado anormal, os quais foram fibroses pós-cirúrgica, em cinco casos (50 por cento); disco residual, em três casos (30 por cento); e dados de compressão radicular, em seis casos (60 por cento). CONCLUSÃO: não há congruência entre os achados da ressonância nuclear magnética e a clínica em pacientes pós-operatórios da discectomia lombar com evolução satisfatória, até o momento, assintomáticos. A ressonância nuclear magnética não é confiável nestes pacientes.

OBJECTIVE: to analyze the postoperative changes in patients undergoing lumbar discectomy, both in patients whose evolution has been satisfactory, as in those with "Failed lumbar Surgery Syndrome", emphasizing the fair value that the nuclear magnetic resonance has. METHODS: the work environment consists of two groups: Group I, five patients with satisfactory evolution and asymptomatic. Group II is composed of ten patients with unsatisfactory results and/or Failed Lumbar Syndrome. The results obtained in the nuclear magnetic resonance image were analyzed, emitting a diagnosis with external evaluation without knowledge of the clinical status of patients, and a correlation with clinical status in both groups was performed. RESULTS: the clinical preoperative manifestations had a very similar distribution. Transoperatory complications were not reported in any of the two groups. In all the groups, the histopathology study was carried out and it was reported the disk degenerated or hyalinization. In Group I, it was not found any abnormality, despite its clinical state. In all the patients, postoperative fibrosis data was found in four cases, and residual disk root was compressed in five patients. In Group II, only in eight patients, the nuclear magnetic resonance showed abnormal findings. The abnormal findings were: fibrosis postoperative in five cases (50 percent), residual disk in three cases (30 percent), and data root compression in six cases (60 percent). CONCLUSION: there is no congruence between the nuclear magnetic resonance and clinic findings, in postoperative patients, of lumbar disectomy with a satisfactory development, who, so far, are asymptomatic. The nuclear magnetic resonance is not reliable in these patients.

Dynamic interspinous stabilization in lumbar discectomy: 4-year follow-up.

BACKGROUND: Semirigid posterior stabilization is an alternative, avoiding arthrodesis in operated segments. However, this results in the need for dynamic stabilization to allow a stable feature function. METHODS: We conducted a prospective longitudinal self-reported interventional study. We included 46 patients with dynamic Dallostype interspinous stabilization between 1997 and 2004. A 4-year follow-up analysis was performed using clinical and radiographic studies, preoperatively and 4 years later evaluating lumbar disability, pain, disc height, disc angle (neutral, flexion, and extension). Descriptive statistics were used along with Wilcoxon signed range test. Statistical significance was accepted when p < 0.05. RESULTS: Of 46 patients, 39 completed a 4-year follow-up. Included in the study were nine females and 30 males with an average age of 30.74 years. Affected levels were L4 and L5 (21 patients); L5/S1 (17 patients) and L3/L4 (one patient). An improvement was reported of 80.3% according to the Oswestry scale (p = 0.0001). Preoperative pain decreased 6.8 points VAS. Disc height decreased 0.1 mm on average without significance. Disc angle (neutral) increased 1.13° without statistical difference. For flexion the increase was 2.641° (p = 0.0002), and extension decreased 0.817° on average without statistical significance. Range of mobility decreased 3.416° (p = 0.004). CONCLUSIONS: Interspinous ligamentoplasty improves segmental stability, allowing mobility within normal ranges and preserving disc height at 4 years of follow-up, as well as offering greater dynamic stability. Successful clinical improvement was demonstrated.

Postoperative spinal wound infections treated by external spinal fixator. Review of three cases.

BACKGROUND: external fixation in the spine has been used with different objectives: to determine the prognosis of spinal fusion, improve stabilization after decompression in cases of trauma and for the progressive correction of scoliosis. Currently, we have not found any reports about its use in the case of postoperative infection with surgical wound dehiscence. CLINICAL CASES: this is a retrospective study of three patients with postoperative infection of the spine and wound dehiscence. All three patients were male and had an average age of 57 years (range: 32-77 years). The infection started at an average of 7 weeks prior to the application of the external fixator (range: 2-12 weeks). Surgical wound dehiscence was on average 7 cm (range: 2-10 cm). The external fixator, on average, was used for 69 days (range: 36-125 days). There were no complications associated with the use of the external fixator. The external fixator was used as definitive treatment in one patient and as a temporary treatment in two patients. CONCLUSIONS: the external fixator may be a useful implant for the treatment of patients with postoperative infections of the spine with surgical wound dehiscence and instability.

Malignant peripheral nerve sheath tumors associated with neurofibromatosis type 1: report of two clinical cases.

BACKGROUND: Malignant peripheral nerve sheath tumor (MPNST) is a sarcoma with a high grade of malignancy originating in the nerve sheath components, fibroblasts, perineural cells, and Schwann cells. It is associated with neurofibromatosis type 1 (NF-1) with a risk of 10-13%. CLINICAL CASES: We present two cases of NF-1-associated MPNST. The first patient presented moderate pain with no apparent cause, in addition to the presence of intraspinal lesion demonstrated by nuclear magnetic resonance imaging (NMRI), which was managed surgically on two occasions. Histologically, it corresponded to a neurofibromatosis lesion in transition with malignant neoplasm. The second case manifested with thoracic kyphoscoliosis, pain, and an increase in volume. Associated with the deformity, MRI showed a withering tumor in the posterior thoracic region (T1-T8), observing an infiltrating, cellular sarcomatous neoplasm with immunopositivity for S-100 protein and vimentin. CONCLUSIONS: MPNSTs are sarcomas with a high index of recurrence with the ability to produce distant metastasis during early stages. Despite wide resection, patients did not survive due to the advancement and size of the lesions (determining factors in the prognosis). Due to the progressive growth of MPNST and the anatomic difficulty for its approach, there should be strict surveillance of patients with NF-1 for early detection of malignant transformation in these lesions.

Tumor de vaina nerviosa periférica maligno asociado a neurofibromatosis tipo 1: informe de dos casos / Malignant peripheral nerve sheath tumors associated with neurofibromatosis type 1: report of two clinical cases

Introducción: El tumor de vaina nerviosa periférica maligno (TVNPM) es un sarcoma de alto grado de malignidad, originado de componentes de las vainas nerviosas, fibroblastos, células perineurales y células de Schwann, que se asocia a neurofibromatosis tipo 1 con un riesgo de 10 a 13 %. Casos clínicos: Se presentan dos casos de TVNPM asociado a neurofibromatosis tipo 1. El primero presentó dolor moderado sin causa aparente, además de lesión intrarraquídea en resonancia magnética nuclear, manejada quirúrgicamente en dos ocasiones. Histológicamente correspondió a lesión neurofibromatosa en transición con neoplasia maligna. El segundo se manifestó con cifoescoliosis torácica, dolor y aumento de volumen. Asociado a la deformidad, la resonancia magnética mostró tumor en la región torácica posterior (T1 a T8), que fue resecado; se identificó neoplasia sarcomatosa infiltrante, muy celular, con inmunopositividad para proteína S100 y vimentina. Conclusiones: Los TNVPM son sarcomas con alto índice de recurrencia, capaces de producir metástasis a distancia desde etapas tempranas. A pesar de la resección amplia, los pacientes descritos no sobrevivieron dado el avance y tamaño de las lesiones. Por el crecimiento progresivo de los TNVPM y la dificultad anatómica para su abordaje, deberá tenerse un control estrecho de los pacientes con neurofibromatosis tipo 1 a fin de identificar tempranamente la transformación maligna de las lesiones.

BACKGROUND: Malignant peripheral nerve sheath tumor (MPNST) is a sarcoma with a high grade of malignancy originating in the nerve sheath components, fibroblasts, perineural cells, and Schwann cells. It is associated with neurofibromatosis type 1 (NF-1) with a risk of 10-13%. CLINICAL CASES: We present two cases of NF-1-associated MPNST. The first patient presented moderate pain with no apparent cause, in addition to the presence of intraspinal lesion demonstrated by nuclear magnetic resonance imaging (NMRI), which was managed surgically on two occasions. Histologically, it corresponded to a neurofibromatosis lesion in transition with malignant neoplasm. The second case manifested with thoracic kyphoscoliosis, pain, and an increase in volume. Associated with the deformity, MRI showed a withering tumor in the posterior thoracic region (T1-T8), observing an infiltrating, cellular sarcomatous neoplasm with immunopositivity for S-100 protein and vimentin. CONCLUSIONS: MPNSTs are sarcomas with a high index of recurrence with the ability to produce distant metastasis during early stages. Despite wide resection, patients did not survive due to the advancement and size of the lesions (determining factors in the prognosis). Due to the progressive growth of MPNST and the anatomic difficulty for its approach, there should be strict surveillance of patients with NF-1 for early detection of malignant transformation in these lesions.

[Primary intradural extramedullary tumors treated at the National Institute of Rehabilitation (Mexico)]. / Tumores intradurales extramedulares primarios tratados en el Instituto Nacional de Rehabilitación.

BACKGROUND: Spine tumors are uncommon injuries affecting a low percentage of the population; however, these tumors can cause significant morbidity and may be related to mortality. They represent 15% of craniospinal tumors. The objective of this study is to determine the frequency of intradural extramedullary spine tumors treated in our Service and to report the definitive histopathological diagnosis. METHODS: This was a retrospective study in a series of patients treated surgically with a diagnosis of intradural extramedullary tumor in the Spine Service of the National Rehabilitation Institute (Mexico) from 1996 to 2006. The following variables were evaluated: gender, age, tumor localization, symptomatology and type of tumor. RESULTS: Files of 27 patients were reviewed. There were 11 men and 16 women with an average age of 47.33 years. The main symptoms were pain and motor weakness. The most frequent localization was thoracic followed by lumbar. Histopathological diagnosis reported 12 cases of meningioma, 12 cases of schwannoma and 3 cases of neurofibroma. CONCLUSIONS: Symptomatology, localization and gender predominance are similar to that reported in the literature. Different from other series, schwannomas and meningiomas were the most frequent tumors in our study. Appropriate diagnosis and opportune treatment consisting of total resection with laminoplasty are crucial in order to avoid permanent neurological consequences.