Comparative tomographic study of the iliac screw and the S2-alar-iliac screw in children

OBJECTIVES: The recent advancements in spine fixation aid in the treatment of complex spinal pathologies. Both the iliac screw (IS) and the S2-alar-iliac (S2AI) screw provide adequate stability in the fixation of complex lumbosacral spine pathologies, leading to a significant increased rate of using these techniques in the daily practice of the spine surgeons. This study aims to analyze, describe, and compare the insertion and positioning parameters of the S2AI screw and IS techniques in children without spinal deformities. METHODS: An observational retrospective study was conducted at a university hospital in 2018, with 25 computed tomography (CT) images selected continuously. Mann-Whitney-Shapiro-Wilk tests were performed. The reliability of the data was assessed using the intraclass correlation. The data were stratified by age group only for Pearson's correlation analysis. RESULTS: The mean age was 11.7 years (4.5 SD). The mean IS length was 106.63 mm (4.59 SD). The mean length of the S2AI screw was 104.13 mm (4.22 SD). The mean skin distance from the IS entry point was 28.13 mm (4.27 SD) and that for the S2AI screw was 39.96 mm (4.54 SD). CONCLUSIONS: Through CT, the S2AI screw trajectory was observed to have a greater bone thickness and skin distance than the IS. There was a linear correlation between age and screw length for both techniques. A similar relationship was observed between skin distance and age for the S2AI screw technique. In children, the S2AI screw technique presents advantages such as greater cutaneous coverage and implant thickness than the IS technique.

Influence of diameter and geometry in the tapping of the pilot hole in pedicle screws / Influência do diâmetro e geometria no macheamento do orifício piloto nos parafusos pediculares / Influencia del diámetro y geometría en el taladramiento del agujero piloto en tornillos pediculares

ABSTRACT Objective: To evaluate the insertion torque and the pulling force of each screw with different diameters and tap. Methods: Polyurethane blocks with a pilot hole of 2.7 mm were used in the study. An experimental group with 5 blocks was formed, the insertion torque was evaluated with a torque meter, and the pullout strength of each Globus screw of 5.5 mm and 6.5 mm was assessed. Results: The comparison of the insertion torque on the 5.5 mm screws with pilot hole without tapping and with a smaller diameter than that of the screw (4.5 mm) and a different thread, and with the tapping with the same diameter as that of the screw (5.5 mm) and equal or different thread presented a statistical difference with a higher value of the insertion torque in the group in which the tapping was not performed. As for the pulling force of the 5.5 mm screw, the non-tapping of the pilot hole resulted in statistical difference with the same diameter of the screw (5.5 mm) and with a different thread of the screw. The pullout force on the 6.5 mm screw was higher in the group where the pilot hole was not tapped according to the non-parametric Kruskal-Wallis test, with significance level of p <0.05 in the comparison of the groups. Conclusions: Pilot hole tapping reduced insertion torque and pullout resistance of the pedicle screw influencing the fixation with tapping with the same screw diameter and different thread design.

RESUMO Objetivo: Avaliar o torque de inserção e a força de arrancamento de cada parafuso com diferentes diâmetros e machos. Métodos: Foram utilizados no estudo blocos de poliuterano com orifício piloto de 2,7mm, sendo feito um grupo experimentais com 5 blocos sendo avaliado o torque de inserção com torquímetro e avaliado o arrancamento de cada parafuso de parafusos Globus 5,5mm e 6,5mm. Resultados: A comparação do torque de inserção nos parafusos de 5,5mm entre a utilização de orifício piloto sem macheamento e o macheamento com diâmetro inferior ao diâmetro do parafuso (4,5mm) e rosca diferente, e com o macheamento com diâmetro igual do parafuso (5,5mm) e com rosca igual ou diferente apresentou diferença estatística com maior valor do torque de inserção no grupo em que o macheamento não foi realizado. Na força de arrancamento do parafuso 5.5mm o não macheamento do orifício piloto apresentou diferença estatística com o mesmo diâmetro do parafuso (5,5mm) e rosca diferente do parafuso. A força de arrancamento no parafuso 6,5mm foi maior no grupo em que o orifício piloto não foi macheado utilizando o teste não paramétrico de Kruskal Wallis com nível de significância adotado (p < 0,05) na comparação dos grupos. Conclusões: O macheamento do orifício piloto diminuiu o torque de inserção e resistência ao arrancamento do parafuso pedicular influenciando a fixação com macheamento com o mesmo diâmetro do parafuso e desenho de rosca diferente.

RESUMEN Objetivo: Evaluar el torque de inserción y la fuerza de extracción de cada tornillo con diferentes diámetros y machos. Métodos: Se utilizaron en el estudio bloques de poliuretano con agujero piloto de 2,7 mm. Se formó un grupo experimental con 5 bloques, y el torque de inserción se evaluó con llave de par y se analizó la fuerza de extracción de cada tornillo Globus de 5,5 mm e 6,5 mm. Resultados: La comparación del torque de inserción en los tornillos de 5,5 mm con agujero piloto sin taladramiento y con un diámetro más pequeño que el del tornillo (4,5 mm) y un roscado diferente, y con el taladramiento con el mismo diámetro que el del tornillo (5,5 mm) y con el roscado igual o diferente presentó una diferencia estadística con un valor más alto del torque de inserción en el grupo en el que no se realizó taladramiento. En cuanto a la fuerza de extracción del tornillo 5,5 mm el no taladramiento del agujero piloto resultó en una diferencia estadística solamente con el mismo diámetro del tornillo (5,5 mm) y con roscado diferente del tornillo. La fuerza de extracción en el tornillo de 6,5 mm fue mayor en el grupo que en el agujero piloto no tuvo taladramiento, de acuerdo con la prueba no paramétrica de Kruskal-Wallis, con nivel de significación de p < 0,05 en la comparación de los grupos. Conclusiones: El taladramiento del agujero piloto redujo el torque de inserción y la resistencia a la extracción del tornillo pedicular, lo que influye con la fijación con taladramiento con el mismo diámetro del tornillo e diferentes diseños de roscado.

Axis screws: results and complications of a large case series

SUMMARY OBJECTIVE: To present the surgical results of patients who underwent axis screw instrumentation, discussing surgical nuances and complications of the techniques used. METHODS: Retrospective case-series evaluation of patients who underwent spinal surgery with axis instrumentation using screws. RESULTS: Sixty-five patients were included in this study. The most common cause of mechanical instability was spinal cord trauma involving the axis (36 patients - 55.4%), followed by congenital craniocervical malformation (12 patients - 18.5%). Thirty-seven (57%) patients required concomitant C1 fusion. Bilateral axis fixation was performed in almost all cases. Twenty-three patients (35.4%) underwent bilateral laminar screws fixation; pars screws were used in twenty-two patients (33.8%), and pedicular screws were used isolated in only three patients (4.6%). In fourteen patients (21.5%), we performed a hybrid construction. There was no neurological worsening nor vertebral artery injury in this series. CONCLUSION: Axis screw instrumentation proved to be a safe and efficient method for cervical stabilization. Laminar and pars screws were the most commonly used

RESUMO OBJETIVO: Apresentar os resultados cirúrgicos de pacientes submetidos à instrumentação com parafusos do áxis, discutindo nuances cirúrgicas e complicações das técnicas utilizadas. MÉTODOS: Série retrospectiva de pacientes submetidos à instrumentação do áxis utilizando parafusos. RESULTADOS: Sessenta e cinco pacientes foram incluídos neste estudo. A causa mais comum de instabilidade foi trauma raquimedular envolvendo o áxis (36 pacientes - 55,4%), seguida por malformação craniocervical congênita (12 pacientes - 18,5%). Trinta e sete (57%) pacientes necessitaram concomitante fusão de C1. Fixação bilateral foi realizada em quase todos os casos. Vinte e três pacientes (35,4%) foram submetidos à fixação com parafusos de lâmina; parafusos de pars foram utilizados em 22 pacientes (33,8%) e de pedículo, isoladamente, em três (4,6%). Em 14 casos (21,5%), realizamos técnicas combinadas. Não houve piora neurológica ou lesão de artéria vertebral nesta série de casos. CONCLUSÃO: A instrumentação com parafusos do áxis foi um método seguro e eficaz para estabilização cervical. A fixação da lâmina e a da pars foram as técnicas mais utilizadas.

A biomechanical study on proximal junctional kyphosis following long-segment posterior spinal fusion

Posterior long-segment spinal fusion may lead to proximal junctional kyphosis (PJK). The present study sought to identify the appropriate fusion levels required in order to prevent PJK using finite element analysis. A finite element model was constructed based on the whole-spine computed tomography findings of a healthy adult. Nine commonly used posterior spinal fusion methods were selected. Stress on the annulus fibrosis fibers, the posterior ligamentous complex, and the vertebrae after various spinal fusions in the upright position were compared. This study was divided into two groups: non-fusion and fusion. In the former, the stress between the T10 and the upper thoracic vertebrae was higher. Comparing thoracic and lumbar segments in the fusion group, the peak stress values of the upper instrumented vertebrae (UIV) were mainly observed in T2 and L2 whilst those of the UIV+1 were observed in T10 and L2. After normalization, the peak stress values of the UIV and UIV+1 were located in T2 and L2. Similarly, the peak stress values of the annulus fibrosus at the upper adjacent level were on T10 and L2 after normalization. However, the peak stress values of the interspinal/supraspinal complex forces were concentrated on T11, T12, and L1 after normalization whilst the peak stress value of the pedicle screw was on T2. Controversy remains over the fusion of T10, and this study simulated testing conditions with gravitational loading only. However, further assessment is needed prior to reaching definitive conclusions.

Posterior L5-S1 transdiscal screws for high grade spondylolisthesis - a systematic review

SUMMARY OBJECTIVE: The surgical management of high-grade lumbar spondylolisthesis (HGLS) is complex and aims to achieve both a solid fusion that is able to support the high shear forces of the lumbosacral junction, as well as neural decompression. We performed a systematic literature review of the safety and efficacy of posterior transdiscal (PTD) screw fixation from L5S1 for HGLS and its variations. METHODS: A systematic literature review following the PRISMA guidelines was performed in the PubMed database of the studies describing the use of PTD screw fixation for HGLS. Clinical and radiological data were extracted and discussed. Study quality was assessed with the Oxford Centre for Evidence-Based Medicine Levels of Evidence. RESULTS: Seven studies were included and reviewed; all of them were level IV of evidence. Two of them had large case series comparing different surgical techniques: one concluded that PTD was associated with better clinical outcomes when compared with standard screw fixation techniques and the other suggesting that the clinical and radiological outcomes of PTD were similar to those when an interbody fusion (TLIF) technique was performed, but PTD was technically less challenging. The remaining five studies included small case series and case reports. All of them reported the successful useful of PTD with or without technical variations. CONCLUSIONS: Our review concludes, with limited level of evidence that PTD fixation is a safe and efficient technique for treating HGLS patients. It is technically less demanding than a circumferential fusion, even though proper screw insertion is more demanding than conventional pedicle screw fixation.

RESUMO OBJETIVOS: O tratamento cirúrgico das listeses de alto grau da coluna lombar (LAGCL) é complexo, objetivando alcançar uma fusão sólida capaz de suportar o estresse biomecânico da junção lombo-sacra, bem como descompressão do tecido neural. Realizamos revisão sistemática da literatura para avaliar a segurança e a eficácia da fixação transdiscal (FTD) L5S1 em LAGCL e suas variações. MÉTODOS: Realizamos revisão sistemática conforme metodologia Prisma na base de dados PubMed dos estudos que utilizaram FTD no tratamento das LAGCL e suas variações. Dados clínicos e radiológicos foram extraídos dos trabalhos e discutidos. A qualidade dos estudos foi avaliada segundo o Oxford Centre for Evidence-Based Medicine Levels of Evidence. RESULTADOS: Sete estudos foram incluídos e analisados, todos com nível IV de evidência. Dois estudos tinham séries de casos maiores, comparando diferentes técnicas cirúrgicas: um concluiu que a FTD foi associada a melhor prognóstico clínico quando comparada à fixação pedicular tradicional, e o outro sugeriu que os resultados clínicos e radiológicos com a FTD foram semelhantes à fusão intersomática, porém com menor demanda técnica na FTD. Os demais cinco estudos eram pequenas séries ou relatos de casos. Todos reportaram o uso da FTD com sucesso, com e sem variações da técnica. CONCLUSÃO: Concluímos que, embora com evidências limitadas, a FTD é segura e efetiva no tratamento das LAGCL. É tecnicamente mais simples do que a fusão circunferencial (intersomática), porém com maior complexidade que a fixação pedicular convencional.

Cobalt chromium-Titanium rods versus Titanium-Titanium rods for treatment of adolescent idiopathic scoliosis; which type of rod has better postoperative outcomes?

SUMMARY OBJECTIVE; Compare the outcome of spinal deformity correction between Ti-Ti and CrCo-Ti rods for the treatment of spinal Adolescent Idiopathic Scoliosis (AIS) using rods mentioned with all pedicle screws and translation technique. METHOD; 59 patients operated for spinal deformity (Lenke 1 or 2) AIS. The patients were divided into two groups by random allocation using Ti-Ti rods (n = 29) and CrCo-Ti rods (n = 30) and the alone difference among them in the surgical procedure was rod material (Ti-Ti or CrCo-Ti rods) and finally, radiological outcomes were compared preoperatively, postoperatively and at last follow-up for 12 months. RESULTS; Patients' main curve correction after surgical procedure regardless type of rod was 48.95±11.04 (13-75) degree. Success rate of spinal deformity correction following surgical procedure regardless of type of administered rod was 86.76 ± 11.30 percent (62.5-100%). Mean of deformity correction rate was 91.49±10.67% using CrCo-Ti rods versus 81.86±9.88% using Ti-Ti rods (P-value=0.01). Angle change was 3.29±6.60 for kyphosis angle and 0.59±7.76 for lordosis angle. Rate of main curve correction was not significantly different considering patients' gender (P-value0.657). Main curve correction success rate was in association with patients' age and type of rod (P-value=0.054, r=-1.863 and P-value=0.001, r=8.865 respectively). CONCLUSION; CrCo-Ti rods have the ability to produce higher correction rates in AIS compared to Ti-Ti rod of the same diameter. CrCo-Ti rods provide significant and stable spinal correction, especially in correction of main curve. This rate was associated with patients' age and type of rod administered but not gender.

RESUMO OBJETIVO: Comparar o resultado da correção da deformidade da coluna vertebral com ligas de Ti-Ti e CrCo-Ti para o tratamento da Escoliose Idiopática do Adolescente (EIA) na coluna usando as ligas mencionadas com todos os parafusos pediculares e técnica de tradução. MÉTODO: 59 pacientes operados por EIA com deformidade da coluna vertebral (Lenke 1 ou 2). Os pacientes foram divididos em dois grupos por alocação aleatória usando ligas de Ti-Ti (n = 29) e ligas de CrCo-Ti (n = 30) e a única diferença entre eles no procedimento cirúrgico foi o material da liga (ligas de Ti-Ti ou CrCo-Ti) e, finalmente, resultados radiológicos foram comparados no pré-operatório, pós-operatório e no último retorno por 12 meses. RESULTADOS: A correção da curva principal do paciente após o procedimento cirúrgico, independentemente do tipo de liga, foi de 48,95±11,04 (13-75) graus. A taxa de sucesso da correção da deformidade da coluna vertebral após o procedimento cirúrgico, independentemente do tipo de liga administrada, foi de 86,76 ± 11,30% (62,5-100%). A média da taxa de correção da deformidade foi de 91,49±10,67% usando ligas de CrCo-Ti e 81,86±9,88% usando ligas de Ti-Ti (valor de P = 0,01). A mudança de ângulo foi de 3,29±6,60 para o ângulo de cifose e de 0,59±7,76 para o ângulo de lordose. A taxa de correção da curva principal não foi significativamente diferente considerando o sexo dos pacientes (Valor de P 0,657). A taxa de sucesso da correção da curva principal foi associada à idade do paciente e ao tipo de liga (valor de P=0,054, r=-1,863 e valor de P=0,001, r=8,865, respectivamente). CONCLUSÃO: As ligas de CrCo-Ti têm a capacidade de produzir taxas de correção mais altas em EIA em comparação com a liga de Ti-Ti do mesmo diâmetro. As ligas de CrCo-Ti fornecem uma correção espinhal significativa e estável, especialmente na correção da curva principal. Essa taxa foi associada à idade e ao tipo de liga administrada, mas não ao sexo.

Comparative study between Plate-Graff, Plate-Cage and PEEK cage in cervical spine fusion / Estudio comparativo entre Plate-Graff, Plate-Cage y Peek cage en la fusión de la columna cervical

Abstract: Objective: To compare results of Plate-Graff, Plate-Cage and PEEK cage in patients with cervical stenosis. Material and methods: Prospective, with before and after intervention and comparative study. From January 2005 to October 2011 we included 37 patients (male: 48.6%, female: 51.4%) post-surgery by anterior approach; 3 groups via: Group I, arthrodesis with Plate-Graff n = 12 (M 41.7%, F 58.3%) with 22 levels, group II, Plate-Cage n = 11 (M 63.6% 36.4% F) 19 levels, group III, PEEK cage, n = 14 (M 0% F 50%) with 25 levels. Functional assessment pre- and postoperative with neck disability index (NDI) and visual analogue scale for pain (VAS). The radiological assessment with X-rays only. Descriptive statistics were obtained. Wilcoxon method use according to data distribution, non parametric tests of ranges with sign of Kruskal-Wallis for comparison between more than two groups, and significance level with p < 0.05. We used the statistical package SPSS version 15. Results: The majority of patients was found between the sixth and eighth decade of life. At one year of follow up the NDI and pain with VAS shown improvement with statistical difference in three groups (p = 0.001). However, the radiographic measurements per year of follow-up showed a significant improvement of segmental lordosis (p = 0.02) only in patients with Plate-Graff. Conclusions: Using the graft offers best clinical and radiographic results compared with the Plate Cage and box peek to one year of follow-up.

Resumen: Objetivo: Comparar resultados de placa-injerto, caja-placa y caja-PEEK, en pacientes con conducto cervical estrecho. Material y métodos: Estudio prospectivo, en panel antes y después, de intervención y comparativo. De Enero de 2005 a Octubre de 2011, muestra de 37 pacientes (masculino: 48.6%, femenino: 51.4%) postoperados por vía anterior; formando tres grupos: grupo I, artrodesis con placa-injerto n = 12 (M 41.7%, F 58.3%) con 22 niveles; grupo II, caja-placa n = 11 (M 63.6%, F 36.4%) con 19 niveles; grupo III, caja-PEEK, n = 14 (M 50%, F 50%) con 25 niveles. La evaluación funcional pre- y postoperatoria mediante la escala de discapacidad cervical y escala visual análoga de dolor. La evaluación radiológica con radiografías de columna cervical. Se obtuvo estadística descriptiva. De acuerdo con la distribución de los datos se usaron pruebas no paramétricas de rangos con signo de Wilcoxon, y Kruskal-Wallis para comparación entre más de dos grupos. Con nivel de significancia de p<0.05. Se utilizó el paquete estadístico SPSS versión 15. Resultados: La mayoría de los pacientes se encontró entre la sexta y octava década de la vida. Al año de postoperados el índice de discapacidad cervical y mejoría del dolor con EVA mostraron mejoría con diferencia estadística en los tres grupos (p = 0.001). Sin embargo, las mediciones radiográficas al año de seguimiento mostraron una mejoría significativa de la lordosis segmentaria (p = 0.02) sólo en pacientes operados con placa-injerto. Conclusiones: El uso de la placa-injerto ofrece mejores resultados clínicos y radiográficos en comparación con la caja-placa y caja-PEEK, al año de seguimiento.

Clinical and radiographic outcomes of upper thoracic versus lower thoracic upper instrumented vertebrae for adult scoliosis: a meta-analysis

The aim of this study was to evaluate the clinical and radiographic outcomes of upper thoracic (UT) versus lower thoracic (LT) upper instrumented vertebrae (UIV) for adult scoliosis by meta-analysis. We conducted a literature search in three databases to retrieve related studies up to March 15, 2017. The preliminary screened studies were assessed by two reviewers according to the selection criteria. All analyses were carried out using the statistical software package R version 2.31. Odds ratios (OR) with 95% confidence intervals (CI) were used to describe the results. The I2 statistic and Q statistic test were used for heterogeneity assessment. Egger's test was performed to detect publication bias. To assess the effect of each study on the overall pooled OR or standardized mean difference (SMD), sensitive analysis was conducted. Ten trials published between 2007 and 2015 were eligible and included in our study. Meta-analysis revealed that the UT group was associated with more blood loss (SMD=0.4779, 95%CI=0.3349-0.6209, Z=6.55, P<0.0001) and longer operating time (SMD=0.5780, 95%CI=0.1971-0.958, Z=2.97, P=0.0029) than the LT group. However, there was no significant difference in Oswestry Disability Index, Scoliosis Research Society (SRS) function subscores, radiographic outcomes including sagittal vertical axis, lumbar lordosis, and thoracic kyphosis, length of hospital stay, and revision rates between the two groups. No evidence of publication bias was found between the two groups. Fusion from the lower thoracic spine (below T10) has as advantages a shorter operation time and less blood loss than upper thoracic spine (above T10) in posterior long-segment fixation for degenerative lumbar scoliosis.

Artificial disc and vertebra system: a novel motion preservation device for cervical spinal disease after vertebral corpectomy

OBJECTIVE: To determine the range of motion and stability of the human cadaveric cervical spine after the implantation of a novel artificial disc and vertebra system by comparing an intact group and a fusion group. METHODS: Biomechanical tests were conducted on 18 human cadaveric cervical specimens. The range of motion and the stability index range of motion were measured to study the function and stability of the artificial disc and vertebra system of the intact group compared with the fusion group. RESULTS: In all cases, the artificial disc and vertebra system maintained intervertebral motion and reestablished vertebral height at the operative level. After its implantation, there was no significant difference in the range of motion (ROM) of C3-7 in all directions in the non-fusion group compared with the intact group (p>0.05), but significant differences were detected in flexion, extension and axial rotation compared with the fusion group (p<0.05). The ROM of adjacent segments (C3-4, C6-7) of the non-fusion group decreased significantly in some directions compared with the fusion group (p<0.05). Significant differences in the C4-6 ROM in some directions were detected between the non-fusion group and the intact group. In the fusion group, the C4-6 ROM in all directions decreased significantly compared with the intact and non-fusion groups (p<0.01). The stability index ROM (SI-ROM) of some directions was negative in the non-fusion group, and a significant difference in SI-ROM was only found in the C4-6 segment of the non-fusion group compared with the fusion group. CONCLUSION: An artificial disc and vertebra system could restore vertebral height and preserve the dynamic function of the surgical area and could theoretically reduce the risk of adjacent segment degeneration compared with the anterior fusion procedure. However, our results should be considered with caution because of the low power of the study. The use of a larger ...

Percutaneous fusion of lumbar facet with bone allograft / Fusão de faceta lombar por via percutânea com aloenxerto ósseo / Fusión facetaria lumbar por vía percutánea con aloinjerto óseo

OBJECTIVE: To assess the evolution of the cases treated with percutaneous facet fusion with bone allograft in lumbar facet disease. METHOD: Between 2010 and 2014, 100 patients (59 women and 41 men) diagnosed with lumbar facet disease underwent surgery. RESULTS: The lumbar facet fusion with bone allograft shows good clinical results, is performed on an outpatient basis, and presents minimal complications and rapid incorporation of the patient to the activities of daily living. CONCLUSIONS: The lumbar facet fusion with bone allograft appears to be an effective treatment for lumbar facet disease. .

OBJETIVO: Avaliar a evolução dos casos tratados com a fusão de faceta por via percutânea com aloenxerto ósseo na doença facetária lombar. MÉTODO: Entre 2010 e 2014, 100 pacientes (59 mulheres e 41 homens) com diagnóstico de doença facetária lombar foram submetidos à cirurgia. RESULTADOS: A fusão de faceta lombar com aloenxerto ósseo mostra bons resultados clínicos, é realizada em ambulatório, apresenta complicações mínimas e incorporação rápida do paciente às atividades da vida diária. CONCLUSÕES: A fusão facetária percutânea com aloenxerto ósseo parece ser um tratamento eficaz para a doença de faceta lombar. .

OBJETIVO: Valorar la evolución de los casos tratados con fusión facetaria por vía percutánea con aloinjerto óseo en la enfermedad facetaria lumbar. MÉTODO: Entre los años 2010 y 2014 se intervinieron 100 pacientes (59 mujeres y 41 hombres) con diagnóstico de enfermedad facetaria lumbar. RESULTADOS: La fusión facetaria lumbar con aloinjerto óseo muestra buenos resultados clínicos, se realiza de forma ambulatoria, presenta mínimas complicaciones y una rápida incorporación del paciente a sus actividades diarias. CONCLUSIONES: La fusión facetaria lumbar con aloinjerto óseo parece ser un tratamiento eficaz para la enfermedad facetaria lumbar. .

Radiologic and Clinical Outcomes of Surgery in High Grade Spondylolisthesis Treated with Temporary Distraction Rod

BACKGROUND: Surgical techniques used in the treatment of patients with high grade lumbar spondylolisthesis (> 50% slippage) are usually associated with a great deal of controversies. We aim to evaluate the surgical outcomes of high grade spondylolisthesis treated with an intraoperative temporary distraction rod. METHODS: We retrospectively studied 21 patients (14 females and 7 males), aged 50.4 +/- 9.2 years, who had high grade lumbar spondylolisthesis that was treated with intraoperative temporary distraction rods, neural decompression, pedicular screw fixation, and posterolateral fusion involving one more intact upper vertebra. The mean follow-up period was 39.2 months. Radiologic and clinical outcomes were measured by slip angle, slip percentage, correction rate, Oswestry Disability Index (ODI), visual analogue scale (VAS), patient's satisfaction rate in the pre- and postoperative period. Data were analyzed by SPSS ver. 11.5. RESULTS: Analysis of the preoperative visits and final follow-up visits indicated that surgery could improve ODI, lumbar VAS, and leg VAS from 60.5% to 8.2%, from 6.7 to 2.2, and from 6.9 to 1.3, respectively. Slip angle and slip percentage were also changed from -8degrees to -15degrees and from 59.2% to 21.4%, respectively. Mean correction rate at the final follow-up visit was 64.1%. Loss of correction was insignificant and a neurologic complication occurred in one patient due to misplacement of one screw. Excellent and good levels of satisfaction were observed in 90.5% of the patients. CONCLUSIONS: In the surgical treatment of refractory high grade spondylolisthesis, the use of a temporary distraction rod to reduce the slipped vertebra in combination with neural decompression, posterolateral fusion, and longer instrumentation is associated with satisfactory clinical and radiologic outcomes.

Anticipation of vertebral pedicle breach through dynamic surgical guidance / Previsão de rotura do pedículo vertebral por meio de guia cirúrgico dinâmico / Previsión de rotura del pedículo vertebral por medio de guía quirúrgica dinámica

OBJECTIVE: To determine the effectiveness of a pedicle probe to anticipate an impending breach and allow redirection during placement of a pilot pedicle hole. METHODS: Purposely four cortical wall sites were drilled: medial and lateral pedicle wall, and lateral and anterior wall of the vertebral body. The surgeon stopped probing when the sound changed, suggesting abutment against the cortical wall ("anticipation" of impending breach). A fluoroscopy image was then obtained. The surgeon then advanced the PediGuard through the cortex until the sound changed, indicating a breach. In the second part of the study three probes were used: 1) DSG (PediGuard) with curved tip with electronics ON; 2) DSG with electronics OFF; 3) standard Lenke probe. After the images were taken, the operating surgeon (blinded to x-rays) was instructed to redirect and continue drilling into the vertebral body. RESULTS: The surgeon accurately anticipated 60 of 75 (80%) of the breaches, 17 of 19 (89%) in the medial pedicle wall. In the second part of the study the DSG with electronics ON was superior to the DSG with electronics OFF as well as the standard Lenke probe (100% vs. 90% vs. 79%, p = 0.0191). CONCLUSION: Successful redirection by passing the pedicle probes into the vertebral body without a breach after anticipation of an impending pedicle wall breach occurred in 100% of the drillings when done with the DSG with the electronics ON vs only 84% when there was no electronic feedback. .

OBJETIVO: Avaliar a efetividade da sonda pedicular para prever a rotura iminente e permitir o redirecionamento durante o posicionamento de orifício piloto no pedículo. MÉTODOS: Intencionalmente, foram feitos quatro orifícios na parede cortical: parede medial e lateral do pedículo e parede lateral e anterior do corpo vertebral. O cirurgião parava a sondagem à mudança do som, que sugeria a proximidade da parede cortical ("previsão" de rotura iminente). A imagem por fluoroscopia era obtida. A seguir, o cirurgião avançava a sonda PediGuard através do osso cortical até a alteração do som, que indicava a rotura. Na segunda parte do estudo foram utilizadas três sondas: GCD (PediGuard) com ponta curva ligada, PediGuard curva desligada e sonda Lenke padrão. Depois que as radiografias eram feitas, o cirurgião (sem ver as imagens) era instruído a redirecionar e a continuar perfurando o corpo vertebral. RESULTADOS: O cirurgião previu com precisão 60 das 75 (80%) roturas, 17 de 19 (89%) na parede medial do pedículo. Na segunda parte do estudo, o guia cirúrgico dinâmico ligado foi superior à desligado, assim como à sonda Lenke padrão (100% vs. 90% vs. 79%, p = 0,0191). CONCLUSÃO: O redirecionamento bem-sucedido da sonda pedicular no interior do corpo vertebral, sem rotura devido à previsão de rotura iminente da parede do pedículo ocorreu em 100% das perfurações com a utilização do o guia cirúrgico dinâmico com o dispositivo ligado, em comparação com 84% das perfurações com o dispositivo desligado. .

OBJETIVO: Evaluar la efectividad de la sonda pedicular para prever la rotura inminente y permitir el redireccionamiento durante el posicionamiento de orificio piloto en el pedículo. MÉTODOS: Intencionalmente, fueron hechos cuatro orificios en la pared cortical: pared medial y lateral del pedículo y pared lateral y anterior del cuerpo vertebral. El cirujano paraba el sondeo al cambiar el sonido, que sugería la proximidad de la pared cortical ("previsión" de rotura inminente). Era obtenida imagen por fluoroscopia. A seguir, el cirujano avanzaba la sonda PediGuard a través del hueso cortical hasta la alteración del sonido, que indicaba la rotura. En la segunda parte del estudio fueron utilizadas tres sondas: ECMT (PediGuard) con punta curva encendida, PediGuard curva apagada y sonda Lenke estándar. Después que las radiografías eran realizadas, el cirujano (sin ver las imágenes) era instruido a redireccionar y a continuar perforando el cuerpo vertebral. RESULTADOS: El cirujano previno con precisión 60 de las 75 (80%) roturas, 17 de 19 (89%) en la pared medial del pedículo. En la segunda parte del estudio, la sonda ECMT encendida fue superior a la apagada, así como a la sonda Lenke estándar (100% vs. 90% vs. 79%, p = 0,0191). CONCLUSIÓN: El redireccionamiento exitoso de la sonda pedicular en el interior del cuerpo vertebral, sin rotura debido a la previsión de rotura inminente de la pared del pedículo ocurrió en 100% de las perforaciones con el uso de la sonda ECMT con el dispositivo encendido, en comparación con 84% de las perforaciones con el dispositivo apagado. .

Avaliação da migração do espaçador intersomático (cage) em pacientes submetidos à artrodese lombar pela técnica TLIF / Migration assessment of interbody spacer in patients undergoing lumbar arthrodesis by technique of TLIF

Objetivo: Avaliar a migração do espaçador intersomático (cage) em pacientes submetidos à artrodese lombar pela técnica transforaminal (TLIF). Método: Estudo retrospectivo de 27 pacientes submetidos à técnica TLIF nos níveis L4-L5, L5-S1 ou L4-L5 e L5-S1 para tratamento de patologia degenerativa da coluna lombar entre julho de 2009 e julho de 2011. Os dados referentes à migração do cage foram obtidos a partir da análise de imagens radiográficas da coluna lombar nas incidências anteroposterior (AP) e perfil nos momentos pré e pós-operatório com 1, 6 e 12 meses. O valor utilizado como critério de migração do cage foi determinado pelo deslocamento anterior ou posterior maior ou igual a 2 mm quando comparado a exame radiográfico pré e pós-operatório. Resultados: Foi inserido um total de 36 cages. Dos 27 pacientes avaliados, 15 (55,5%) apresentavam algum tipo de migração do cage - em 4 (14,8%) a migração foi para anterior e em 11 (40,7%) a migração foi para posterior. Conclusão:Encontramos migração em 55,5% do total de pacientes, e em 40,7% a migração foi posterior, porém sem necessidade de novas intervenções cirúrgicas.

Objective: To evaluate the cage migration in transforaminal lumbar interbody fusion (TLIF). Method: We retrospectively reviewed the records of 27 patients who had been diagnosed with degenerative lumbar disease, and who had undergone a transforaminal lumbar interbody fusion at L4-L5, L5-S1, and L4-L5/L5-S1 between July 2009 and July 2011. All data regarding the cage migration was obtained from preoperative and postoperative radiographs including standing anteroposterior (AP) and lateral. Clinical and radiographic assessment was performed at 1, 6 and 12 months after surgery. Cage migration was identified if cage moved posteriorly 2 mm or more compared with previous radiographs. Results: 36 cages were inserted. Cage migration was found in 15 of 27 patients (55,5%). Four cases of anterior displacement (14,8%) and 11 cases of posterior displacement (40,7%) were found. Conclusion: The rate of cage migration was 55.5%. In addition, 40.7% of posterior displacement was found but without further surgical intervention.

Cifosis de unión proximal en curvas Lenke 5C. Comparación entre cirugía anterior y cirugía posterior / Proximal junctional kyphosis in lenke c5 curves. A comparison between anterior and posterior surgery

Introducción: El balance sagital es crítico para los resultados a largo plazo en el manejo quirúrgico de la escoliosis idiopática del adolescente. La cifosis de unión se podría definir como un hallazgo radiológico en la transición de la columna fusionada y la columna móvil en pacientes asintomáticos. El objetivo de este trabajo fue comparar la cifosis de unión proximal posoperatoria en curvas Lenke 5C con dos técnicas quirúrgicas distintas: la instrumentación anterior y la instrumentación posterior. Materiales y Métodos: Estudio retrospectivo, controlado no aleatorizado, de 37 pacientes con escoliosis idiopática del adolescente, curvas Lenke 5C con fusión corta, de vértebra límite a vértebra límite. Grupo 1: 18 pacientes con artrodesis anterior instrumentada y Grupo 2: 19 pacientes con artrodesis posterior instrumentada. Los parámetros sagitales radiológicos medidos fueron: 1) línea de plomada de C7, 2) cifosis de unión, 3) cifosis torácica, 4) lordosis lumbar, con un seguimiento mínimo de 2 años. Resultados: Grupo 1: aumento de la cifosis de unión entre el preoperatorio y el seguimiento a los 2 años de 6,27° (p = 0,0002). La incidencia de cifosis de unión patológica fue del 17 por ciento. Grupo 2: aumento de la cifosis de unión entre el preoperatorio y el seguimiento de 4,63° (p = 0,0004). La incidencia de cifosis de unión patológica fue del 16 por ciento. Conclusión: No hubo diferencias significativas entre ambos grupos en la incidencia de cifosis de unión patológica.

Background: Sagittal balance is critical for long-term results in the surgical handling of adolescent idiopathic scoliosis. Proximal junctional kyphosis could be defined as a radiographic findings in the fused and mobile spine transition in asymptomatic patients. Objective: To compare post-surgical proximal junctional kyphosis in Lenke C5 curves with two different surgical techniques: anterior and posterior instrumentation. Methods: Retrospective, controlled, non-randomized study of 37 patients with Lenke C5 adolescent idiopathic scoliosis, with short fusion from end-vertebra to end-vertebra. Group 1: 18 patients with anterior instrumented arthrodesis, and Group 2: 19 patients with posterior instrumented arthrodesis. The radiographic sagittal parameters measured were: 1) plumbline from the C7, 2) junctional kyphosis, 3) thoracic kyphosis, and 4) lumbar lordosis; with a minimum follow-up of two years. Results: Group 1: increase of junctional kyphosis between the preoperative period and a two-year follow-up, 6.27° (p = 0.0002). The incidence of pathologic junctional kyphosis was 17%. Group 2: increase of junctional kyphosis between the preoperative period and the follow- up, 4.63° (p = 0.0004). The incidence of pathologic junctional kyphosis was 16%. Conclusion: There were no significant differences between groups in the incidence of pathologic junctional kyphosis.

Modificaciones del plano sagital cervical luego del tratamiento quirúrgico posterior en la escoliosis idiopática del adolescente Lenke 1 / Changes in the cervical alignment after posterior transpedicular instrumentation in Lenke type I adolescent idiopathic scoliosis

Introducción: Como la cifosis toracica y la lordosis cervical son directamente proporcionales, las modificaciones del plano sagital toracico impactarian sobre la columna cervical. Nuestro objetivo fue detectar cambios en el plano sagital cervical, a corto y mediano plazo, durante el tratamiento quirurgico segun una tecnica posterior. Materiales y Métodos: Estudio retrospectivo radiografico de tipo serie de casos, entre enero de 2005 y abril de 2009. Criterios de inclusion: escoliosis idiopatica del adolescente Lenke 1, tratamiento por via posterior con tornillos transpediculares. Seguimiento minimo 2 anos. Parametros analizados: nivel Cobb, nivel de instrumentacion proximal, densidad de implantes, lordosis cervical, cifosis toracica proximal, cifosis toracica principal, inclinacion sagital T1, balance sagital global, balance sagital cervical. Analisis estadistico mediante ANOVA de muestras repetitivas y Tukey, con el programa Graph-Pad-Prism. Resultados: 25 pacientes. Seguimiento promedio 4,3 anos. Cifosis toracica: media preoperatoria 26,8o, posoperatoria 20,6o. Efecto lordotizante despues del tratamiento quirurgico (p ≤0,001). La inclinacion sagital T1 y la cifosis proximal T2-T5 (p ≤0,038) mostraron un incremento hacia el ultimo control. El 72 % presentaba rectificacion o cifosis cervical antes de la cirugia. El 44 % experimento una mejoria hacia el ultimo control. Los niveles de artrodesis mas altos se correlacionaron con los casos que empeoraron su contorno sagital posoperatorio. Conclusiones: Nuestra tecnica de correccion genero un efecto lordotizante toracico. Esto se tradujo, a mediano plazo, en un incremento de la retropulsion del tronco y rectificacion o perdida de la lordosis a nivel cervical...

Background: As thoracic kyphosis and cervical lordosis are proportionally related, every change in the thoracic sagittal plane will impact on the cervical alignment. Our objective was to detect changes in the sagittal cervical plane at short- and medium term follow-up during surgical treatment, according to the posterior technique. Methods: Retrospective, radiographic case series study performed between January 2005 and April 2009. Inclusion criteria: Lenke type 1 adolescent idiopathic scoliosis, and posterior screw fixation surgery. Radiographic parameters: Cobb angle, uppermost instrumented vertebra, implant density, cervical lordosis, proximal thoracic kyphosis, main thoracic kyphosis, T1 sagittal tilt, global sagittal balance and cervical sagittal balance. Statistical analysis: ANOVA of repetitive samples and Tukey, using the Graph-Pad-Prism. Results: 25 patients. Mean follow-up 4.3 years. Thoracic kyphosis (T5-T12): average, preoperative 26.8º and 20.6º postoperative. Lordosing effect after surgical treatment (p ≤0.001). T1 sagittal tilt and T2-T5 proximal thoracic kyphosis (p ≤0.038) tended to increase at last control. Seventy two per cent of our sample showed rectification or even cervical kyphosis before surgery. Only 44 % had certain better alignment at the last follow-up. Higher UIV correlated with a worse cervical plane alignment after surgery. Conclusions: Our derotational concavity technique with poliaxial pedicle screws and titanium 5.5 rod demonstrated a lordosing effect in the thoracic sagittal plane. This was translated into a trunk retropulsion and rectification or lost of lordosis in the sagittal cervical plane in the medium-term follow-up...

Dynamic compared to rigid fixation in lumbar spine: a systematic review / Fixação pedicular dinâmica comparada com a fixação rígida na coluna lombar: uma revisão sistemática

Objective: The objective of this review is to reveal the quality of published data and the effect size of DPFs compared to rigid fixation in lumbar spine. Summary of background data: since 2002, several dynamic pedicle fixation (DPF) systems have been developed with the aim to stabilize the spine without the undesirable effects of rigid lumbar spine fixation. Nearly ten years later, there are several studies on these dynamic systems. Methods: A systematic review was done in MEDLINE/PubMED, Embase, Cochrane Central Register of Randomized Trials and Google Scholar to assess the quality of published literature and the available studied outcomes in randomized controlled trials of DPF. Results: Only three papers described randomized trials studying DPF. One of them focused on protection of adjacent level disease provided by DPF. Conclusion: It was not possible to reveal any evidence for benefits using DPF compared to rigid fixation in surgery for lumbar spine. .

Objetivo: Desde 2002, vários sistemas de fixação dinâmica pedicular (FDP) foram desenvolvidos com o objetivo de estabilizar a coluna vertebral, sem os efeitos indesejáveis da fixação da coluna lombar rígida. Cerca de 10 anos mais tarde, existe uma série de estudos sobre os sistemas dinâmicos. Revelar a qualidade dos dados publicados e o tamanho do efeito da FDP em comparação com a fixação rígida na coluna lombar. Métodos: Uma revisão sistemática foi feita utilizando MEDLINE/ PubMed, Embase, a CENTRAL Cochrane de ensaios randomizados e Google Scholar para avaliar a qualidade da literatura publicada e os desfechos estudados disponíveis em ensaios clínicos randomizados. Resultados: Apenas três estudos randomizados foram encontrados. Um deles estudou a proteção de degeneração no nível adjacente à fixação rígida proporcionada pela FDP. Conclusão: Não foi possível revelar qualquer evidência de benefícios da FPD, em comparação com a fixação rígida em cirurgia para a coluna lombar. .

Parafusos pediculares mal posicionados pela técnica freehand: qual o real valor para o surgimento de lesões neurológicas? / Misplaced pedicle screws by the freehand technique: what is the real value for the occurrence of neurological lesions? / Tornillos pediculares mal posicionados por técnica "freehand": ¿cuál es el valor real de la aparición de las lesiones neurológicas?

OBJETIVO: Verificar a existência de lesões neurológicas nos pacientes submetidos à instrumentação com parafusos pediculares mal posicionados na região toracolombar. MÉTODOS: Estudo prospectivo com seleção randômica de 30 pacientes submetidos à instrumentação pedicular por via posterior, pela técnica freehand. Foi avaliada comparativamente, de forma cega, a adequação do posicionamento dos parafusos nas vértebras por meio de tomografias. A seguir, tentou-se correlacionar a existência de alterações neurológicas relacionadas ao posicionamento dos implantes. RESULTADOS: Observados 223 parafusos pediculares na coluna toracolombar em 30 pacientes operados no serviço por diversas doenças. Houve violação da parede do pedículo vertebral em 33% dos pacientes, sendo mais da metade com invasão da cortical medial. A piora neurológica no pós-operatório imediato ocorreu em três pacientes, entretanto apenas um parafuso precisou de reposicionamento. Todos os pacientes recuperaram a situação neurológica pré-cirúrgica. CONCLUSÕES: O índice de violação cortical com parafusos pediculares mostrou-se elevado. Contudo, nota-se que pequenas violações pediculares podem causar danos neurológicos e que, quando esses acontecem, são reversíveis se o erro for corrigido.

OBJECTIVE: To verify the presence of neurological damages in patients submitted to instrumentation with thoracolumbar pedicle screws misplacement. METHODS: Prospective study with a random selection of 30 patients submitted to pedicular instrumentation by posterior approach with freehand technique. Screws vertebral positioning was comparatively and blindly evaluated with tomographies. Then, we tried to correlate neurological status with screws placement. RESULTS: Thirty patients submitted to spinal surgery at this hospital for any disease had instrumentation with 223 pedicle screws. Vertebral pedicle wall violation was observed in 33% of cases, and more than half of them had medial cortical breach. Neurological worsening occurred in three patients in the immediate postoperative period, but only one screw needed repositioning. All patients recovered the previous neurological status. CONCLUSION: A high level of pedicle screw cortical violation was observed. However, small pedicle breaches may originate neurological damages and, when they occur, the lesions are reversible if the misplaced screws are corrected.

OBJETIVO: Comprobar si hay lesiones neurológicas en pacientes sometidos a la instrumentación con tornillos pediculares mal posicionados en la región toracolumbar. MÉTODOS: Se realizó un estudio prospectivo con selección aleatoria de 30 pacientes sometidos a la instrumentación pedicular posterior a través de la técnica "freehand". Se evaluó comparativamente en forma ciega, la conveniencia de la colocación de tornillos en las vértebras con visualización por TC. A continuación, tratamos de correlacionar la presencia de trastornos neurológicos relacionados con la colocación de los implantes. RESULTADOS: Fueron observados 223 tornillos pediculares en la columna toracolumbar en 30 pacientes operados en el servicio debido a diversas enfermedades. Hubo una violación de la pared del pedículo en un 33% de los casos, siendo que más de la mitad con invasión de la cortical medial. El empeoramiento neurológico en el postoperatorio inmediato se produjo en tres pacientes, aunque fue necesario cambiar la posición de un solo tornillo. Todos los pacientes recuperaron su estado neurológico preoperatorio. CONCLUSIONES: La tasa de violación cortical con tornillos pediculares fue alta. No obstante, se observó que las pequeñas violaciones pediculares pueden causar daño neurológico y que cuando esto sucede, es reversible si se corrige el error.

Análise radiográfica comparativa da cifose juncional entre instrumentação híbrida, ganchos e parafusos na escoliose idiopática do adolescente / Comparative radiographic analysis of junctional kyphosis between hybrid instrumentation, hooks and screws in adolescent idiopathic scoliosis / Análisis radiográfico comparativo de la cifosis de unión entre los instrumentos híbridos, los ganchos y los tornillos en escoliosis idiopática del adolescente

OBJETIVO: Avaliação radiográfica das cifoses juncionais proximal e distal em pacientes submetidos a artrodese e diferentes tipos de instrumentação posterior no tratamento cirúrgico da escoliose idiopática do adolescente (EIA). MÉTODO: Foi realizado estudo retrospectivo com avaliação radiográfica de 34 pacientes submetidos à artrodese da coluna vertebral com instrumentação posterior, sendo 10 com ganchos (Grupo I), 13 com ganchos e parafusos (Grupo II) e 11 com parafusos (Grupo III), entre junho de 1997 e dezembro de 2009. Foi avaliada a ocorrência de cifose juncional proximal (CJP) e cifose juncional distal (CJD) à artrodese, no pré-operatório, no pós-operatório imediato e no final do seguimento, pós-operatório tardio, que foi de, no mínimo, 12 meses. RESULTADOS: Os pacientes do grupo I apresentaram cifose torácica de menor valor no pré-operatório, porém a lordose lombar permaneceu inalterada ao longo da evolução. Os pacientes do grupo II e grupo III apresentaram aumento do valor aferido da lordose lombar no pós-operatório. Não houve diferença significativa para a ocorrência de cifose juncional proximal entre os três grupos estudados. Com relação à cifose juncional distal, houve aumento estatisticamente significativo do valor entre pré é pós-operatório, para os grupos II e III. CONCLUSÃO: A avaliação radiográfica das cifoses juncionais proximal e distal em pacientes submetidos à artrodese e diferentes tipos de instrumentação no tratamento cirúrgico da EIA revelou a presença de cifoses juncionais proximais pré-operatórias, que não evoluíram para a deformidade juncional pós-operatória, além de ausência completa da anormalidade juncional distal.

OBJECTIVE: Radiographic evaluation of proximal and distal junctional kyphosis in patients undergoing spinal fusion and different types of posterior instrumentation, in the surgical treatment for adolescent idiopathic scoliosis (AIS). METHOD: A retrospective review was done with radiographic evaluation of 34 patients who were submitted to spinal fusion with posterior instrumentation, divided as follows: 10 using only hooks (Group I), 13 hybrid fixation (screws and hooks) (Group II) and 11 using only pedicle screws (Group III) from June 1997 to December 2009. The study assessed the occurrence of junctional kyphosis both proximal and distal to the arthrodesis, in the preoperative, immediate postoperative periods, in the final follow up, and also in the late postoperative period, which was at least 12 months. RESULTS: Patients in group I showed lower value of thoracic kyphosis preoperatively, but the lumbar lordosis remained unchanged throughout evolution. Patients in group II and group III showed an increase in the assessed value of lumbar lordosis postoperatively. There was no significant difference in the occurrence of proximal junctional kyphosis among the three groups. Regarding the distal junctional kyphosis, there was a statistically significant increase in value between the preoperative and postoperative for groups II and III. CONCLUSION: Radiographic evaluation of the proximal and distal junctional kyphosis in patients who underwent arthrodesis and different types of instrumentation in the surgical treatment of adolescent idiopathic scoliosis, revealed the presence of preoperative proximal junctional kyphosis, which have not progressed to postoperative junctional deformity, and also complete absence of distal junctional abnormality.

OBJETIVO: Evaluación radiográfica de cifosis por unión proximal y distal en pacientes sometidos a artrodesis y diferentes tipos de instrumentación como tratamiento quirúrgico de escoliosis idiopática del adolescente (EIA). MÉTODO: Se realizó un estudio retrospectivo de evaluación radiográfica de 34 pacientes sometidos a artrodesis de la columna con instrumentación posterior, 10 con ganchos (Grupo I), 13 con ganchos y tornillos (Grupo II) y 11 con tornillos (Grupo III), entre junio de 1997 y diciembre de 2009. Se evaluó la aparición de cifosis proximal y distal a la artrodesis en los períodos preoperatorio, postoperatorio inmediato y al final del seguimiento, período postoperatorio tardío, de por lo menos 12 meses. RESULTADOS: Los pacientes del Grupo I presentaron menor valor de cifosis torácica preoperatoria, pero la lordosis lumbar se mantuvo sin cambios durante la evolución. Los pacientes en el grupo II y grupo III mostraron incremento del valor verificado de lordosis lumbar en el postoperatorio. No hubo diferencia significativa en la aparición de cifosis proximal a la unión entre los tres grupos. En cuanto a la cifosis por unión distal, se produjo un aumento estadísticamente significativo del valor entre preoperatorio y postoperatorio en los grupos II y III. CONCLUSIÓN: La evaluación radiográfica de la cifosis por unión proximal y distal en pacientes sometidos a artrodesis y diferentes tipos de instrumentación como tratamiento quirúrgico de escoliosis idiopática del adolescente reveló la presencia preoperatoria de cifosis proximales a la unión , que no evolucionaron para deformidad postoperatoria por unión y además, ausencia completa de anormalidad de la unión distal.

Axis instrumentation: surgical results / Instrumentação do áxis: resultados cirúrgicos

OBJECTIVE: Evaluate the surgical results of axis screw instrumentation. METHODS: Retrospective evaluation of the clinical and radiological data of patients submitted to axis fixation using screws. RESULTS: Seventeen patients were surgically treated. The mean age was 41.8 years (range: 12-73). Spinal cord trauma was the most common cause of instability (8 patients - 47%). Bilateral axis fixation was performed in all cases, except one, with laminar screw (total of 33 axis screws). Seven patients (41.1%) underwent bilateral pars screws; laminar screws were used in six cases and pedicular screws were used in two. In two cases, we performed a hybrid construction (laminar + pars and pedicle + pars). There was no neurological worsening or death, nor complications directly related to use axis screws. CONCLUSION: Axis instrumentation was effective and safe, regardless of the technique used for stabilization. Based on our learnt experience, we proposed an algorithm to choose the best technique for axis screw fixation.

OBJETIVO: Avaliar os resultados cirúrgicos da instrumentação com parafusos do áxis. MÉTODOS: Avaliação retrospectiva de dados clínicos e radiológicos de pacientes submetidos à instrumentação com parafusos do áxis. RESULTADOS: Dezessete pacientes foram tratados cirurgicamente. A média de idade foi de 41,8 anos (faixa: 12-73 anos). Trauma na coluna foi a causa mais comum de instabilidade (8 casos - 47%). Fixação bilateral do áxis foi realizada em todos os casos, exceto em um, com parafuso de lâmina (total de 33 parafusos). Em sete pacientes (41,1%), foram usados parafusos de pars; em seis, parafusos de lâmina; e em dois, de pedículos. Em dois casos, foi utilizada uma combinação de técnicas (pars + lâmina e pars + pedículo). Não houve piora neurológica nem complicações diretas em decorrência do uso dos parafusos. CONCLUSÃO: A instrumentação do áxis foi eficaz e segura independentemente da técnica escolhida para estabilização. Com base em nossa experiência, foi proposto um algoritmo para auxílio na escolha da melhor técnica a ser empregada.

Espaciador interespinoso tipo DIAM: experiencia en Puerto Montt / DIAM interspinous spacer type: experience in Puerto Montt

El lumbago crónico constituye un problema de salud pública por su frecuencia y afección a población joven, económicamente activa. Se presenta en el presente artículo, un análisis de la biomecánica de la columna lumbar, y la importancia de los vectores de carga en la génesis del dolor, y las posibilidades de intervenir sobre ellos con la instalación de dispositivos interespinosos. Se exponen las distintas alternativas de espaciadores interespinosos y se presenta la experiencia con el DIAM. Se analizan los resultados de 17 pacientes sometidos a cirugía por lumbago crónico por fracaso a tratamiento médico quinésico, con la instalación de 26 dispositivos, destacando la buena evolución de la mayoría de ellos, con reducción significativa del dolor (EVA pre y postoperatorio) y análisis de capacidad funcional por escala de Oswestry luego de la cirugía. Todos los pacientes fueron intervenidos por el autor.

Chronic low back pain constitutes a public health problem by its frequency and affection in young population, economically active. This article presents an analysis of the biomechanics of the lumbar spine, and the importance of load vectors in pain genesis, and the possibilities to act on them with interspinous device installation. Here are exposed interspinous spacers alternatives and presents experience with the DIAM. We analyze the results of 17 patients undergoing surgery for chronic low back pain by failure of kinesics medical treatment, with the installation of 26 devices, highlighting the good performance of most of them with significant reduction in pain (VAS pre-and postoperative) and functional capacity analysis Oswestry scale after surgery. All patients were operated on by the author.