Escoliosis idiopática del adolescente, análisis postoperatorio. Serie de casos / Idiopathic adolescent scoliosis, post-operative analysis. Case Series

Introducción La escolisis es una deformidad tridimencional de la columna vertebral. El objetivo principal del tratamiento es evitar la progresión, lograr la máxima corrección y la artrodesis del menor numero de segmentos, con buen balance coronal y sagital que permita una fusión indolora. El objetivo del estudio es evaluar los resultados de los pacientes operados por escolisis idiopática del adoelscente en nuestro centro. Materiales y Métodos se realizó un estudio tipo serie de casos, se incluyeron pacientes operados entre 2011 y 2017; en ellos se estudiaron: los datos demografícos, el tipo de curva, la densidad de tornillos utilizados, el porcentaje de reducción lograda al año y las complicaciones. Resultados Se obtuvieron datos de 27 pacientes. Pedominaron las curva Lenke 1B. El ángulo de Cobb preoperatorio promedio fue de 66,5o con un postoperatorio de24,4o. La densidad de tornillo presentó un promedio de 1,4. Presentaron complicaciones el 25,6% de los pacientes, siendo la más frecuente la infección. En el cuestionario SRS-22 se obtuvieron buenas resultados. Discusión Se ha reportado una densidad de 0,8-1,69 tornillos por vértebra fusionada con un porcentaje de corrección de 64-70%. En nuestro resultados la densidad de tornillos por vertebra fusionado fue de 1,4 lográndose una reduccion de 64,1%. Aumentar el número de tornillos no aumentó el grado de corrección de las curvas. En concordancia con la literatura la complicación mas frecuente fue la infección, con baja incidencia de lesión neurológica. Concluimos que la técnica de artrodesis utilizada en nuestro centro, con tornillos pediculares de tercera generación, obtiene buenos resultados de reducción, con porcentaje de complicaciones similares a los reportados previamente.

Background Scoliosis is a three-dimensional deformity of the spine. The main objective of treatment is to avoid progression, achieve maximum correction and arthrodesis of the least number of segments, with good coronal and sagittal balance that allows a painless fusion. The aim of the study is to evaluate the results of patients who underwent to surgical fusion for adolescent idiopathic scoliosis. Material and Methods A case series study was conducted by analyzing medical records of patients who underwent to surgical fusion for adolescent idiopathic scoliosis. between 2011 through 2017.An analysis of demographic data, the type of curve, the density of screws used, the percentage of reduction achieved after one year, and complications was performed. Results Data of 27 patients was included. Lenke 1B curves were predominant. The mean preoperative Cobb angle was 66.5o with a postoperative 24.4o. Screw density presented an average of 1.4. Complications were presented in 25.6% of the patients, the most frequent being infection. Good results were obtained in the SRS-22 questionnaire. Discussion A density of 0.8-1.69 screws per fused vertebra has been reported with a correction percentage of 64-70%. In our results, the density of screws per fused vertebra was 1.4, achieving a reduction of 64.1%. Increasing the number of screws did not increase the degree of correction of the curves. In accordance with the literature, the most frequent complication was infection, with a low incidence of neurological injury. We conclude that the arthrodesis technique used in our center, with third-generation pedicle screws, obtains good reduction results, with a percentage of complications similar to those previously reported.

Pullout Strength Predictor: A Machine Learning Approach

STUDY DESIGN: A biomechanical study. PURPOSE: To develop a predictive model for pullout strength. OVERVIEW OF LITERATURE: Spine fusion surgeries are performed to correct joint deformities by restricting motion between two or more unstable vertebrae. The pedicle screw provides a corrective force to the unstable spinal segment and arrests motions at the unit that are being fused. To determine the hold of a screw, surgeons depend on a subjective perioperative feeling of insertion torque. The objective of the paper was to develop a machine learning based model using density of foam, insertion angle, insertion depth, and reinsertion to predict the pullout strength of pedicle screw. METHODS: To predict the pullout strength of pedicle screw, an experimental dataset of 48 data points was used as training data to construct a model based on different machine learning algorithms. A total of five algorithms were tested in the Weka environment and the performance was evaluated based on correlation coefficient and error matrix. A sensitive study of various parameters for obtaining the best combination of parameters for predicting the pullout strength was also preformed using the L9 orthogonal array of Taguchi Design of Experiments. RESULTS: Random forest performed the best with a correlation coefficient of 0.96, relative absolute error of 0.28, and root relative squared error of 0.29. The difference between the experimental and predicted value for the six test cases was not significant (p >0.05). CONCLUSIONS: This model can be used clinically for understanding the failure of pedicle screw pullout and pre-surgical planning for spine surgeon.

Application of biomimetic mineralized collagen bone graft material on rabbits posterolateral spinal fusion / 中国修复重建外科杂志

Objective: To investigate the bone repair and regeneration ability of biomimetic mineralized collagen bone graft material and autologous bone marrow in rabbit posterolateral spinal fusion model. Methods: Twenty-seven 20-week-old male New Zealand white rabbits ［weighing (5.0±0.5) kg］ were used to establish the posterolateral spinal fusion model of L 5 and L 6 segments by stripping the transverse process and exposing cancellous bone with electric burr. The rabbits were randomly divided into 3 groups, 9 in each group. Groups A, B, and C were implanted 1.5 mL autologous iliac bone, 1.5 mL (30 mm×10 mm×5 mm) biomimetic mineralized collagen bone graft material, and 1.5 mL (30 mm×10 mm×5 mm) biomimetic mineralized collagen bone graft material and autologous bone marrow in each bone defect. At 4, 8, and 12 weeks after operation, the apparent hardness of the bone grafting area was observed by manipulation method, in order to evaluate bone graft fusion effects. Three animals were sacrificed in each group at each time point, the vertebral body specimens were excised and the bone defect repair and fusion were observed by X-ray films, and three-dimensional CT examination was performed to evaluate whether new bone was formed in the body. HE staining was performed at each time point to observe the formation of new bone and the repair and fusion of bone defects. Results: The manipulation test showed that bone graft fusion was not found in all groups at 4 weeks after operation; 3 (50.0%), 2 (33.3%), and 4 (66.7%) of groups A, B, and C reached bone graft fusion at 8 weeks after operation; 5 (83.3%), 4 (66.7%), and 5 (83.3%) of groups A, B, and C reached bone graft fusion at 12 weeks after operation; the fusion rate of group C was similar to that of group A, and all higher than that of group B. X-ray film observation showed that the fusion rate of group C at 8 and 12 weeks after operation was higher than that of group B, similar to group A. Three-dimensional CT observation showed that the effect of bone fusion in group C was better than that in group B, which was close to group A. HE staining observation showed that large area of mature lamellar bone coverage appeared in the bone graft area of groups A, B, and C at 12 weeks after operation, the material was completely degraded, and the marginal boundary of the host bone disappeared and tightly combined. Conclusion: Biomimetic mineralized collagen bone graft material mixed with autologous bone marrow has good osteoinduction and osteogenesis guidance. Compared with biomimetic mineralized collagen bone graft material, it has better and faster osteogenesis effect, which is close to autologous bone transplantation.

Postoperative complications of suction drain in patients submitted to 1-level lumbar arthrodesis / Complicações pós-operatória do dreno de sucção em pacientes submetidos a artrodese lombar de um nível / Complicaciones postoperatório del dreno de succión en pacientes sometidos a artrodesis lumbar de un nivel

ABSTRACT Objective: To evaluate the complications inherent in the use or not of continuous suction drain in postoperative period of patients undergoing 1-level lumbar arthrodesis. Methods: An analytical, comparative, randomized study was performed with a sample of 60 patients submitted to 1-level 360o lumbar arthrodesis with TLIF technique, 30 of whom used the suction drain for three days after surgery and another 30 did not use the suction drain in the postoperative period. The complications that occurred on the 3rd, 14th, and 28th postoperative days of patients of both groups and the Visual Analog Scale for pain were evaluated and compared. The complications assessed were seroma, superficial infection and suture dehiscence. Results: A total of 23.3% surgical wound complications were found, the most frequent being seroma (16%). In total, each group presented seven complications. There were no statistical differences observed in the evaluation of seroma, infection, wound dehiscence on the 3rd, 14th, and 28th postoperative days in both groups. Conclusion: The use or not of suction drain in 1-level lumbar surgeries does not interfere with complications such as seroma, infection, and suture dehiscence.

RESUMO Objetivo: Avaliar as complicações inerentes à utilização ou não de dreno de sucção contínua em pós-operatório de pacientes submetidos a artrodese lombar de um nível. Métodos: Estudo analítico, comparativo, randomizado, com uma amostra de 60 pacientes submetidos a artrodese lombar de 360º em um nível com técnica TLIF, sendo que 30 utilizaram o dreno de sucção por três dias no pós-operatório e outros 30 não utilizaram o dreno de sucção no pós-operatório. Foram avaliadas e comparadas as complicações surgidas no 3°, 14° e 28° dias pós-operatório dos pacientes de ambos os grupos e a Escala Visual Analógica para dor. As complicações avaliadas foram seroma, infecção superficial e deiscência de sutura. Resultados: Encontrou-se um total de 23,3% de complicações da ferida cirúrgica, sendo a mais frequente o seroma (16%). No total das complicações cada grupo apresentou sete. Não foram observadas diferenças estatísticas na avaliação de seroma, infecção, deiscência de sutura no 3º, 14º e 28º dia de pós-operatório em ambos os grupos. Conclusão: A utilização ou não de dreno de sucção em cirurgias lombares em um nível não interfere no surgimento das complicações como seroma, infecção e deiscência de sutura.

RESUMEN Objetivo: Evaluar las complicaciones inherentes a la utilización o no de drenaje de succión continua en el postoperatorio de pacientes sometidos a artrodesis lumbar de un nivel. Métodos: Estudio analítico, comparativo, aleatorizado, con una muestra de 60 pacientes sometidos a artrodesis lumbar de 360o de un nivel con técnica TLIF, siendo que 30 utilizaron el drenaje de succión por tres días en el postoperatorio y otros 30 no utilizaron el drenaje en el postoperatorio. Se evaluaron y compararon las complicaciones surgidas en los días 3, 14 y 28 de días del postoperatorio de los pacientes en ambos grupos y la escala analógica visual para el dolor. Las complicaciones evaluadas fueron seroma, infección superficial y dehiscencia de sutura. Resultados: Se encontró un total de 23,3% de complicaciones de la herida quirúrgica, siendo el seroma la más frecuente (16%). En el total de las complicaciones cada grupo presentó siete. No se observaron diferencias estadísticas en la evaluación de seroma, infección, dehiscencia de sutura en el 3o, 14o y 28o día de postoperatorio en ambos grupos. Conclusión: El uso o no de drenaje de succión en cirugías lumbares de un nivel no interfiere en la aparición de complicaciones como seroma, infección y dehiscencia de sutura.

Comparison of Clinical and Radiological Outcomes of Lumbar Interbody Fusion Using a Combination of Hydroxyapatite and Demineralized Bone Matrix and Autografts for Lumbar Degenerative Spondylolisthesis

STUDY DESIGN: Prospective, cohort, non-inferiority study. PURPOSE: This study evaluated the clinical and radiological outcomes of interbody fusion using a combination of demineralized bone matrix (DBM) and hydroxyapatite (HA). OVERVIEW OF LITERATURE: The use of autografts remains a gold standard in lumbar interbody fusion, but the limited availability and donor site morbidity encourages the use of bone substitutes. In addition to autografts, a combination of HA and DBM is being increasingly use for lumbar interbody fusion. However, there are no data on the clinical and radiological outcomes of this procedure. METHODS: We examined 35 patients with lumbar degenerative spondylolisthesis who underwent transforaminal interbody fusion. Autografts were used in 18 patients, and 17 patients received a combination of HA and DBM. Clinical outcomes were evaluated using the visual analog scale (VAS) for back and leg pain, Oswestry disability index (ODI), and Japanese Orthopaedic Association (JOA) scores at 3, 6, and 12 months postoperatively. Fusion was evaluated using computed tomography images obtained at 12 months postoperatively. RESULTS: The mean ODI, JOA, and back and leg pain VAS scores increased significantly in both groups. However, the VAS, JOA, and ODI scores did not differ significantly between the two groups (p=0.599, p=0.543, and p=0.780, respectively). The fusion rates at 1 year postoperatively were 77.8% and 76.5% in the autograft and HA+DBM groups, respectively (p=0.99). CONCLUSIONS: The clinical and radiological outcomes of using a combination of HA and DBM in lumbar interbody fusion were not inferior to those of using autografts. A combination of HA and DBM can be considered as an alternative in patients with lumbar degenerative spondylolisthesis requiring surgery.

Tratamiento quirúrgico de las fracturas por estallamiento de columna toracolumbar / Traitement chirurgical des fractures-éclatement du rachis thoracolombaire

Introducción: las fracturas vertebrales constituyen un grave problema de salud, la zona toracolumbar constituye la localización más frecuente. El tratamiento quirúrgico, en fracturas por estallamiento, parece el de mejores resultados pero presenta la disyuntiva de si a todos los pacientes se les debe realizar fusión. Objetivo: mostrar los resultados obtenidos a los dos años con el tratamiento quirúrgico de las fracturas por estallamiento de columna toracolumbar, en los servicios de Ortopedia y Neurocirugía del Hospital Calixto García entre enero de 2011 y julio de 2013. Método: estudio descriptivo prospectivo en pacientes con diagnóstico de fracturas toracolumbares por estallamiento tratados quirúrgicamente, asociando en algunos a la fijación, la fusión. Las variables estudiadas: edad, sexo, mecanismo causal, localización, tipo de fractura, deformidad cifótica y altura del cuerpo vertebral. El índice de Oswestry y la Escala Visual Analógica del dolor, medidos antes y dos años después de la intervención, fueron los instrumentos evaluadores empleados. Resultados: serie constituida por 28 pacientes, predominaron el sexo masculino, y el accidente automovilístico como mecanismo causal; la localización más frecuente fue en el segmento T11-L2 para las fracturas tipo A3 y A4 según AO; las variaciones de deformidad cifótica y altura del cuerpo vertebral fueron muy semejantes a los dos años entre pacientes con fusión y sin ella. El índice de Oswestry y la Escala Visual Analógica del dolor mostraron significativa mejoría. Conclusiones: los resultados radiográficos y funcionales fueron similares en pacientes con fusión y sin ella. La fusión posterior no necesita ser un procedimiento de rutina en fracturas por estallamiento de columna toracolumbar(AU)

Introduction: vertebral fractures are serious health problem; the thoracolumbar zone is the most frequent location. Surgical treatment in explant fractures seems to be the one with the best results but presents the dilemma of whether all patients should be fusion. Objective: show the results obtained at two years with the surgical treatment of thoracolumbar spine fractures in Orthopedics and Neurosurgery services at Calixto García Hospital from January 2011 to July 2013. Method: prospective descriptive study was carried out in patients with diagnosis of surgically treated thoracolumbar fractures, associated to fixation, fusion. The variables studied were age, sex, causal mechanism, location, type of fracture, kyphotic deformity and vertebral body height. The Oswestry Index and Visual Analog Pain Scale, measured before and two years after the intervention, were the evaluation instruments used. Results: twenty-eight patients formed this series, the male sex predominated, and automobile accident was a causal mechanism. The most frequent location was segment T 11- L 2 for fractures type A 3 and A 4 according to AO. The variations of kyphotic deformity and height of the vertebral body were very similar after two years in patients with and without fusion. Oswestry Index and Visual Analog Pain Scale showed significant improvement. Conclusions: radiographic and functional results were similar in patients with and without fusion. Post fusion does not need to be a routine procedure in thoracolumbar collapse fractures (AU)

Introduction: les fractures vertébrales, étant plus fréquemment localisées dans la région thoracolombaire, constituent un sérieux problème de santé. Le traitement chirurgical des fractures-éclatement semble être le meilleur étant donnés ses résultats, mais il pose un question -est-ce que tous les patients doivent subir une fusion? Objectif: l'objectif de cette étude est de montrer les résultats obtenus deux ans après le traitement chirurgical des fractures-éclatement thoracolombaires aux services d'orthopédie et de neurochirurgie, à l'hôpital "Calixto García" entre janvier 2011 et juillet 2013. Méthode: une étude descriptive et prospective des patients diagnostiqués et traités chirurgicalement pour des fractures-éclatement thoracolombaires, associant la fixation et la fusion dans certains cas, a été effectuée. Des variables telles que l'âge, le sexe, les causes, la localisation, le type de fracture, la déformation cyphotique, et la taille du corps vertébral ont été aussi étudiées. L'indice d'Oswestry et l'échelle visuelle analogique de la douleur ont été les outils d'évaluation utilisés auparavant et deux ans après l'opération. Résultats: dans une série de 28 patients, ce sont les hommes le plus souvent touchés, tandis que l'accident de voiture a été la cause la plus fréquemment trouvée ; les fractures type A3 et A4, selon AO, se sont souvent localisées au niveau du segment T11-L2 ; les variations de la déformation cyphotique et la taille du corps vertébral ont été très similaires au bout de deux ans chez les patients ayant subi ou pas une fusion. L'indice d'Oswestry et l'échelle visuelle analogique de la douleur ont montré une amélioration significative. Conclusions: les résultats radiologiques et fonctionnels ont été similaires chez les patients ayant subi ou pas une fusion. La fusion postérieure n'est pas nécessairement un procédé habituel dans les fractures-éclatement du rachis thoracolombaire (AU)

Correlation between quality of life and osteolysis around lumbar pedicle screws / Relação entre qualidade de vida e osteólise em torno de parafusos pediculares lombares / Correlación entre calidad de vida y osteólisis alrededor de tornillos pediculares lumbares

ABSTRACT Objective: To evaluate whether the presence of osteolysis around the pedicle screws affects the quality of life of patients who underwent posterolateral arthrodesis of the lumbosacral spine. Methods: A retrospective study of patients undergoing lumbar posterolateral or lumbosacral arthrodesis due to spinal degenerative disease. CT scans of the operated segments were performed at intervals of 45, 90, 180, and 360 postoperatively. In these tests, the presence of a peri-implant radiolucent halo was investigated, which was considered present when greater than 1mm in the coronal section. Concurrently with the completion of CT scans, the participants completed the questionnaire Oswestry Disability Index (ODI) to assess the degree of disability of the patients. Results: A total of 38 patients were evaluated, and 14 (36.84%) of them showed some degree of osteolysis around at least one pedicle screw at the end of follow-up. Of the 242 analyzed screws, 27 (11.15%) had osteolysis in the CT coronal section, with the majority of these occurrences located at the most distal level segment of the arthrodesis. There was no correlation between the presence of the osteolysis to the quality of life of patients. The quality of life has significantly improved when comparing the preoperative results with the postoperative results at different times of application of ODI. This improvement in ODI maintains linearity over time. Conclusion: There is no correlation between the presence of peri-implant osteolysis to the quality of life of patients undergoing lumbar or posterolateral lumbosacral arthrodesis in the follow-up period up to 360 days. The quality of life in postoperative has significantly improvement when compared to the preoperative period.

RESUMO Objetivo: Avaliar se a presença de osteólise em torno dos parafusos pediculares influencia a qualidade de vida de pacientes submetidos à artrodese posterolateral da coluna lombossacral. Métodos: Estudo retrospectivo com pacientes submetidos à artrodese posterolateral lombar ou lombossacral por doença espinal degenerativa. Foram realizadas tomografias computadorizadas dos segmentos operados em intervalos de 45, 90, 180 e 360 dias de pós-operatório. Nesses exames, foi pesquisado a presença de um halo radiolucente peri-implante, que foi considerado presente quando maior que 1 mm no corte coronal. Concomitantemente à realização dos exames de TC foi aplicado o questionário Oswestry Disability Index (ODI) para avaliar o grau de incapacidade dos pacientes. Resultados: Foram avaliados 38 pacientes e 14 (36,84%) deles apresentavam algum grau de osteólise ao redor de pelo menos um parafuso pedicular ao final do seguimento. Dos 242 parafusos analisados, 27 (11,15%) apresentaram osteólise no corte coronal da TC, sendo a maioria dessas ocorrências no nível mais distal do segmento com artrodese. Não se observou relação da presença dessa osteólise com a qualidade de vida dos pacientes. A qualidade de vida tem melhora significativa quando se compara o resultado pré-operatório com os resultados pós-operatórios nos diversos momentos de aplicação do ODI. Essa melhora no ODI mantém a linearidade de melhora com o passar do tempo. Conclusão: Não há relação da presença da osteólise peri-implante com a qualidade de vida dos pacientes submetidos à artrodese lombar ou lombossacral posterolateral no período de seguimento até os 360 dias. A qualidade de vida pós-operatória tem melhora significativa quando comparada ao momento pré-operatório.

RESUMEN Objetivo: Evaluar si la presencia de osteólisis alrededor de los tornillos pediculares afecta la calidad de vida de los pacientes que fueron sometidos a artrodesis posterolateral de la columna lumbosacra. Métodos: Estudio retrospectivo de pacientes sometidos a artrodesis lumbar posterolateral o lumbosacra debido a enfermedad degenerativa de la columna vertebral. Se realizaron tomografías computarizadas de los segmentos operados en intervalos de 45, 90, 180 y 360 días después de la cirugía. En estas pruebas, fue investigada la presencia de un halo radiotransparente alrededor del implante, que se consideró presente cuando era mayor que 1 mm en corte coronal. Simultáneamente con la realización de las tomografías se aplicó el cuestionario Oswestry Disability Index (ODI) para evaluar el grado de discapacidad de los pacientes. Resultados: Se evaluaron 38 pacientes y 14 (36,84%) de ellos tenían algún grado de osteólisis alrededor de al menos un tornillo pedicular al final del seguimiento. De los 242 tornillos analizados, 27 (11,15%) tenían osteólisis en el corte coronal de la tomografía, estando la mayoría de estas ocurrencias, en el nivel más distal de la artrodesis. No hubo correlación entre la presencia de la osteólisis a la calidad de vida de los pacientes. La calidad de vida ha mejorado de manera significativa al comparar los resultados preoperatorios con los resultados postoperatorios en sus distintos momentos del ODI. Esta mejora en el ODI mantiene linealidad de mejoría con el tiempo. Conclusión: No existe correlación entre la presencia de osteólisis alrededor del implante a la calidad de vida de los pacientes sometidos a artrodesis posterolateral lumbar o lumbosacra en el período de seguimiento de hasta 360 días. La calidad de vida postoperatoria ha mejorado significativamente en comparación con el período preoperatorio.

Nonoperative versus operative treatment of patients with degenerative spondylolisthesis / Tratamento conservador versus cirúrgico de pacientes com espondilolistese degenerativa / Tratamiento conservador contra quirúrgico de pacientes con espondilolistesis degenerativa

ABSTRACT Objective: To evaluate clinical and functional results of patients with lumbar degenerative spondylolisthesis treated with operatively or nonoperatively. Methods: Patients with degenerative spondylolisthesis treated either nonoperatively or operatively from 2004 to 2014 were selected from databases and a cross-sectional evaluation was performed. Outcome measures included back and leg visual analogue scales (VAS), Fischgrund criteria, Short Form-36 (SF-36) function score, and the modified Oswestry Disability Index (ODI). Results: 43 patients were evaluated: 20 with nonoperative treatment and 23 with operative treatment. Baseline characteristics were similar without significant differences between groups. Mean follow-up time was 43 months (range 10 - 72) for the nonoperative group and 36 months (range 6-80) for the operative group. Significant statistical difference in favor of operative group were found in back VAS (mean 4 versus 8, p = 0.000), leg VAS (mean 3 versus 6, p = 0.0015), SF-36 function score (mean 77 versus 35, p = 0.000), and ODI (mean 17 versus 46, p = 0.000). On the basis of the Fischgrund criteria, only 10 % of patients reported excellent or good health post nonoperative treatment versus 83% for those treated operatively (p = 0.000). Conclusion: In this cross-sectional study, we observed that symptomatic patients with degenerative spondylolisthesis who underwent operative treatment have superior clinical and functional scores compared to those that underwent nonoperative treatment.

RESUMO Objetivo: Avaliar os resultados clínicos e funcionais dos pacientes com espondilolistese degenerativa lombar tratados de maneira conservadora ou cirúrgica. Métodos: Foram selecionados pacientes com espondilolistese degenerativa tratados conservadoramente ou submetidos à cirurgia, durante 2004-2014, à partir da coleta de dados que possibilitou a realização da avaliação transversal. As medidas de avaliação da dor lombar e das pernas foram escalas analógicas visuais (VAS), critérios Fischgrund, Short Form-36 (SF-36) pontuação funcional, e o Índice de Incapacidade Oswestry modificado (ODI). Resultados: 43 pacientes foram avaliados: 20 do tratamento conservador e 23 do tratamento cirúrgico. As características de base foram similares, sem diferenças significativas entre os grupos. O tempo médio de acompanhamento foi de 43 meses (intervalo 10-72) para o grupo não-cirúrgico e 36 meses (intervalo 6-80) para o grupo cirúrgico. Diferenças estatísticas significativas em favor do grupo cirúrgico foram encontrados no VAS lombar (média de 4 versus 8, p = 0,000), VAS pernas (média 3 contra 6, p = 0,0015), SF-36 pontuação funcional (média 77 versus 35, p = 0,000), e ODI (média 17 versus 46, p = 0,000). Com base nos critérios Fischgrund, apenas 10% dos pacientes relataram excelente ou boa saúde de após o tratamento conservador contra 83% para aqueles tratados no cirúrgico (p = 0,000). Conclusão: Neste estudo transversal, observou-se que os pacientes sintomáticos com espondilolistese degenerativa que se submeteram ao tratamento cirúrgico têm escores clínicos e funcionais superiores em comparação àqueles que foram submetidos a tratamento conservador.

RESUMEN Objetivo: Evaluar los resultados clínicos y funcionales de los pacientes con espondilolistesis degenerativa lumbar tratados quirúrgicamente o sin cirugía. Métodos: Se realizó una evaluación transversal de los pacientes con espondilolistesis degenerativa, registrados en la base de datos, tratados conservador o quirúrgicamente desde 2004 hasta 2014. Las medidas de desenlace incluyeron: Escala Visual Análoga (EVA) de dolor lumbar y las piernas, criterios de Fischgrund, Short Form-36 (SF-36) e Índice de Discapacidad Oswestry modificado (IDO). Resultados: Se evaluaron 43 pacientes: 20 con tratamiento no quirúrgico y 23 con tratamiento quirúrgico. Las características de base fueron similares, sin diferencias significativas entre los grupos. El tiempo medio de seguimiento fue de 43 meses (rango 10-72) para el grupo no quirúrgico y 36 meses (rango 6-80) para el grupo quirúrgico. Diferencias estadísticamente significativas a favor del grupo quirúrgico fueron encontrados en EVA lumbar (media 4 contra 8, p=0,000), EVA pierna (media 3 contra 6, p=0,0015), SF-36 función (media 77 contra 35, p=0,000), e IDO (media 17 contra 46, p=0,000). Con respecto a los criterios de Fischgrund, sólo el 10% de los pacientes del grupo que recibió tratamiento no quirúrgico informo excelente o buen estado de salud en comparación con 83% de los que recibieron manejo quirúrgico (p = 0,000) Conclusión: En este estudio de corte transversal, se observó que los pacientes sintomáticos con espondilolistesis degenerativa que se sometieron a tratamiento quirúrgico tienen puntuaciones clínicas y funcionales superiores en comparación con los que se sometieron a tratamiento no quirúrgico.

Comparative Analysis of Effect of Density, Insertion Angle and Reinsertion on Pull-Out Strength of Single and Two Pedicle Screw Constructs Using Synthetic Bone Model

STUDY DESIGN: Biomechanical study. PURPOSE: To determine the effect of density, insertion angle and reinsertion on pull-out strength of pedicle screw in single and two screw-rod configurations. OVERVIEW OF LITERATURE: Pedicle screw pull-out studies have involved single screw construct, whereas two screws and rod constructs are always used in spine fusions. Extrapolation of results using the single screw construct may lead to using expensive implants or increasing the fusion levels specifically in osteoporotic bones. METHODS: Single screw and two screw pull-out strength tests were carried out according to American Society for Testing and Materials F 543-07 on foam models to test the effect of density, insertion angle and reinsertion using poly axial pedicle screws. RESULTS: Bone density was the most significant factor deciding the pull-out strength in both single and two screw constructs. The difference in pull-out strength between single screw and two screw configurations in extremely osteoporotic bone model (80 kg/m3) was 78%, whereas in the normal bone model it was 48%. Axial pull-out value was highest for the single screw configuration; in the two screw configuration the highest pull-out strength was at 10°-15°. There was an 18% reduction in pull-out strength due to reinsertion in single screw configuration. The reinsertion effect was insignificant in the two screw configuration. CONCLUSIONS: A significant difference in response of various factors on holding power of pedicle screw between single and two-screw configurations is evident. The percentage increase in pull-out strength between single and two screw constructs is higher for osteoporotic bone when compared to normal bone. Reinsertion has no significant effect on pull-out strength in the two screw rod configuration.

Comparative Analysis of Effect of Density, Insertion Angle and Reinsertion on Pull-Out Strength of Single and Two Pedicle Screw Constructs Using Synthetic Bone Model

STUDY DESIGN: Biomechanical study. PURPOSE: To determine the effect of density, insertion angle and reinsertion on pull-out strength of pedicle screw in single and two screw-rod configurations. OVERVIEW OF LITERATURE: Pedicle screw pull-out studies have involved single screw construct, whereas two screws and rod constructs are always used in spine fusions. Extrapolation of results using the single screw construct may lead to using expensive implants or increasing the fusion levels specifically in osteoporotic bones. METHODS: Single screw and two screw pull-out strength tests were carried out according to American Society for Testing and Materials F 543-07 on foam models to test the effect of density, insertion angle and reinsertion using poly axial pedicle screws. RESULTS: Bone density was the most significant factor deciding the pull-out strength in both single and two screw constructs. The difference in pull-out strength between single screw and two screw configurations in extremely osteoporotic bone model (80 kg/m3) was 78%, whereas in the normal bone model it was 48%. Axial pull-out value was highest for the single screw configuration; in the two screw configuration the highest pull-out strength was at 10°-15°. There was an 18% reduction in pull-out strength due to reinsertion in single screw configuration. The reinsertion effect was insignificant in the two screw configuration. CONCLUSIONS: A significant difference in response of various factors on holding power of pedicle screw between single and two-screw configurations is evident. The percentage increase in pull-out strength between single and two screw constructs is higher for osteoporotic bone when compared to normal bone. Reinsertion has no significant effect on pull-out strength in the two screw rod configuration.

Correlation between obesity, sagittal balance and clinical outcome in spinal fusion / Correlação entre obesidade, equilíbrio sagital e resultado clínico em artrodese da coluna vertebral / Correlación entre obesidad, equilibrio sagital y resultado clínico en la artrodesis espinal

Objective:To correlate obesity with radiographic parameters of spinal and spinopelvic balance in patients undergoing spinal arthrodesis, and to correlate obesity with clinical outcome of these patients.Methods:Observational retrospective study including patients who underwent spinal arthrodesis, with minimum follow-up period of three months. We measured waist circumference, as well as height and weight to calculate body mass index (BMI) and obtained radiographs of the total column. The clinical parameters studied were pain by visual analog scale (VAS) and the Oswestry questionnaire (ODI). Obesity correlated with radiographic parameters of the sagittal and spinopelvic balance and postoperative clinical parameters.Results:32 patients were analyzed. The higher the BMI, the greater the value of VAS found, but without statistical significance (p=0.83). There was also no correlation between BMI and the ODI questionnaire. Analyzing the abdominal circumference, there was no correlation between the VAS and ODI. There was no correlation between BMI or waist circumference and the radiographic parameters of global spinopelvic sagittal alignment. Regarding the postoperative results, there was no correlation between the mean BMI and waist circumference and the postoperative results for ODI and VAS (p=0.75 and p=0.7, respectively).Conclusions:The clinical outcomes of patients who undergone spinal fusion were not affected by the BMI and waist circumference. Also, there was no correlation between radiographic parameters of spinal and spinopelvic sagittal balance with obesity in patients previously treated with arthrodesis of the spine.

Objetivo:Correlacionar a obesidade com os parâmetros radiográficos do equilíbrio sagital espinhal e espinopélvico em pacientes submetidos à artrodese da coluna vertebral, além de correlacionar a obesidade com o resultado clínico de tais pacientes.Métodos:Estudo observacional, retrospectivo, que incluiu pacientes submetidos a artrodese da coluna vertebral, com período de seguimento mínimo de três meses. Medimos a circunferência abdominal, assim como a altura e o peso, para o cálculo do índice de massa corporal (IMC) e obtivemos radiografias da coluna total. Os parâmetros clínicos estudados foram: dor pela escala visual analógica (EVA) e o questionário de Oswestry (ODI). Correlacionamos obesidade com os parâmetros radiográficos do equilíbrio sagital e espinopélvico e com os parâmetros clínicos pós-operatórios.Resultados:Foram analisados 32 pacientes. Quanto maior o IMC, maior foi o valor da EVA encontrado, porém sem significância estatística (p = 0,83). Também não houve correlação entre o IMC e o questionário ODI. Analisando a circunferência abdominal, não houve correlação com EVA ou ODI. Não houve correlação entre IMC ou circunferência abdominal e os parâmetros radiográficos do alinhamento sagital e espinopélvico. Quanto ao resultado pós-operatório, não houve correlação entre as médias do IMC e da circunferência abdominal e o resultado pós-operatório pelo ODI e pela EVA (p = 0,75 e p = 0,7, respectivamente).Conclusões:Os resultados clínicos de pacientes submetidos a artrodese da coluna vertebral não foram alterados pelo IMC e pela circunferência abdominal. Também não se observou correlação entre os parâmetros radiográficos do equilíbrio sagital espinhal e espinopélvico com a obesidade em pacientes previamente submetidos a cirurgia de artrodese da coluna vertebral.

Objetivo:Correlacionar la obesidad con los parámetros radiográficos del equilibrio sagital vertebral y espinopélvico en pacientes sometidos a artrodesis vertebral y correlacionar la obesidad con la resultado clínico de estos pacientes.Métodos:Estudio observacional y retrospectivo que incluyó pacientes sometidos a la artrodesis de la columna vertebral con un período de seguimiento mínimo de tres meses. Se midió la circunferencia de la cintura, así como la altura y el peso para calcular el índice de massa corporal (IMC) y se obtuvo radiografías de la columna total. Los parámetros clínicos estudiados fueron el dolor mediante la escala visual analógica (EVA) y el cuestionario de Oswestry (ODI). La obesidad fue correlacionada con los parámetros radiográficos del balance sagital y espinopélvico y parámetros clínicos postoperatorios.Resultados:Se analizaron 32 pacientes. Cuanto mayor sea el índice de masa corporal, mayor será el valor de EVA, pero sin significación estadística (p = 0,83). Tampoco hubo correlación entre el IMC y el cuestionario ODI. Analizando la circunferencia abdominal, no hubo correlación con EVA u ODI. No hubo correlación entre el IMC o la circunferencia de la cintura y los parámetros radiográficos de la alineación sagital y espinopélvica. En cuanto el resultado postoperatorio, no hubo correlación entre la media de IMC y la circunferencia de la cintura y los resultados postoperatorios por el ODI o EVA (p = 0,75 y p = 0,7, respectivamente).Conclusiones:Los resultados clínicos de pacientes sometidos a la artrodesis de la columna vertebral no se vieron afectados por el IMC y la circunferencia de la cintura. Además no había correlación entre los parámetros radiográficos del equilibrio sagital de la columna y el espinopélvico con la obesidad en pacientes previamente tratados con artrodesis de la columna vertebral.

Reproducibility of tomographic evaluation of posterolateral lumbar arthrodesis consolidation / Reprodutibilidade da avaliação tomográfica da consolidação de artrodeses posterolaterais lombares / Reproducibilidad de la evaluación tomográfica de la consolidación de artrodesis posterolaterales lumbares

To evaluate interobserver agreement of Glassman classification for posterolateral lumbar spine arthrodesis.

Avaliar a concordância interobservadores da classificação de Glassman para artrodese posterolateral da coluna lombar.

Evaluar la concordancia entre observadores de la clasificación de Glassman para artrodesis posterolateral de la columna lumbar.

Perioperative Surgical Complications and Learning Curve Associated with Minimally Invasive Transforaminal Lumbar Interbody Fusion: A Single-Institute Experience

BACKGROUND: As surgical complications tend to occur more frequently in the beginning stages of a surgeon's career, knowledge of perioperative complications is important to perform a safe procedure, especially if the surgeon is a novice. We sought to identify and describe perioperative complications and their management in connection with minimally invasive transforaminal lumbar interbody fusion (TLIF). METHODS: We performed a retrospective chart review of our first 124 patients who underwent minimally invasive TLIF. The primary outcome measure was adverse events during the perioperative period, including neurovascular injury, implant-related complications, and wound infection. Pseudarthroses and adjacent segment pathologies were not included in this review. Adverse events that were not specifically related to spinal surgery and did not affect recovery were also excluded. RESULTS: Perioperative complications occurred in 9% of patients (11/124); including three cases of temporary postoperative neuralgia, two deep wound infections, two pedicle screw misplacements, two cage migrations, one dural tear, and one grafted bone extrusion. No neurologic deficits were reported. Eight complications occurred in the first one-third of the series and only 3 complications occurred in the last two-thirds of the series. Additional surgeries were performed in 6% of patients (7/124); including four reoperations (two for cage migrations, one for a misplaced screw, and one for an extruded graft bone fragment) and three hardware removals (one for a misplaced screw and two for infected cages). CONCLUSIONS: We found perioperative complications occurred more often in the early period of a surgeon's experience with minimally invasive TLIF. Implant-related complications were common and successfully managed by additional surgeries in this series. We suggest greater caution should be exercised to avoid the potential complications, especially when surgeon is a novice to this procedure.

Functional assessment of patients with cervical myelopathy who underwent surgical treatment / Avaliação funcional de pacientes com mielopatia cervical submetidos a tratamento cirúrgico / Evaluación funcional de los pacientes con mielopatía cervical sometidos a tratamiento quirúrgico

OBJECTIVE: Evaluate and correlate the functional response of patients with cervical myelopathy with the current clinical scores in patients who underwent surgical treatment. METHODS: We analyzed medical records of 34 patients with cervical myelopathy who underwent four different types of surgery. All patients were evaluated preoperatively and postoperatively with the application of the JOA and Nurick questionnaires. RESULTS: Functional clinical improvement was statistically significant. The mean preoperative JOA was 8.5 ± 3.06 and 10.7 ± 3.9 in the postoperative; Nurick was 3.2 ± 1.1 preoperatively and 2.8 ± 1.3 postoperatively. CONCLUSION: There is benefit with the surgical procedure in patients with cervical myelopathy. The neurological function after surgery depends on the previous function (the higher the duration of the previous symptoms, the greater the progression of the disease and, therefore, worse the neurological function) and the age is not a relevant factor of improvement, as already shown in other series. The clinical functional improvement of patients is visible with surgical treatment, regardless of surgical technique. .

OBJETIVO: Avaliar e correlacionar a resposta funcional dos pacientes com mielopatia cervical com os escores clínicos já existentes, em pacientes que foram submetidos ao tratamento cirúrgico. MÉTODOS: Trabalho retrospectivo com análise de 34 prontuários de pacientes portadores de mielopatia cervical que foram submetidos a quatro diferentes tipos de cirurgia. Todos os pacientes foram avaliados no pré e pós-operatório com a aplicação dos questionários de JOA e Nurick. RESULTADOS: A melhora clínica funcional foi estatisticamente relevante. O JOA pré-operatório médio foi de 8,5 ± 3,06 para 10,7 ± 3,9, no pós-operatório e o Nurick foi 3,2 ± 1,1 no pré-operatório e de 2,8 ± 1,3 no pós-operatório. CONCLUSÃO: Há benefício com a realização do tratamento cirúrgico em pacientes com mielopatia cervical, a função neurológica pós-operatória depende da função prévia (quanto maior o tempo de sintomas, maior progressão e, com isso pior a função neurológica) e a idade dos pacientes não é fator relevante de melhora, como já mostrado em outras séries. A melhora funcional clínica dos pacientes, é visível com o tratamento cirúrgico, independente da técnica cirúrgica aplicada. .

OBJETIVO: Evaluar y correlacionar la respuesta funcional de los pacientes con mielopatía cervical con las puntuaciones clínicas vigentes en pacientes sometidos a tratamiento quirúrgico. MÉTODOS: Se analizaron los registros médicos de 34 pacientes con mielopatía cervical que se sometieron a cuatro diferentes tipos de cirugía. Todos los pacientes fueron evaluados antes y después de la cirugía con la aplicación de los cuestionarios JOA y Nurick. RESULTADOS: La mejoría clínica funcional fue estadísticamente significativa. El JOA preoperatorio promedio fue de 8,5 ± 3,06 y 10,7 ± 3,9 en el postoperatorio. El Nurick antes de la operación fue 3,2 ± 1,1 y 2,8 ± 1,3 después de la operación. CONCLUSIÓN: Existe beneficio con el tratamiento quirúrgico en pacientes con mielopatía cervical. La función neurológica después de la cirugía depende de la función previa (cuanto mayor sea la duración de los síntomas anteriores, mayor será la progresión de la enfermedad y, por lo tanto, peor es la función neurológica) y la edad no es un factor relevante de la mejora, como ya se ha demostrado en otras series. La mejora clínica funcional de los pacientes es visible con el tratamiento quirúrgico, independientemente de la técnica quirúrgica y esto está directamente relacionado con su condición antes de la cirugía. .

Robotic-Assisted Device in Posterior Spinal Fusion for a High Risk Thoraculombar Fracture in Ankylosing Spondylitis

Fractures in ankylosing spondylitis (AS) are often difficult to treat and surgical treatment may be fraught with complications. We describe the use of a robotic-assisted device in the surgical treatment of an unstable L1 fracture in an elderly patient with chronic lymphocytic leukemia and AS. The postoperative course was uneventful and the patient was discharged after 3 days. The use of a robotic-assisted device in spine surgery is particularly indicated in difficult high risk cases.

Comparison of anterior cervical discectomy and fusion and anterior cervical corpectomy and fusion for the treatment of multi-segmental cervical spondylotic myelopathy / 中国医师进修杂志

Objective To compare the clinical results of two different anterior cervical surgical treatment for multi-segmental cervical spondylotic myelopathy (≥3 segments).Methods Twenty-three patients with segmental cervical spondylotic myelopathy,10 cases were treated with anterior cervical discectomy and fusion (ACDF) as ACDF group,13 cases were treated with anterior cervical corpectomy and fusion (ACCF) as ACCF group.The operation time,operative blood loss,JOA scores,neurological improvement rate and the variable of the D value were compared.Results The operation time and operative blood loss in ACDF group was significantly lower than that in ACCF group [(130.0 ±31.5) min vs.(150.0 ±42.5) min,(150.0 ± 120.8) ml vs.(310.0 ± 320.8) ml,P ＜ 0.05].The variable of the D value in ACDF group was significantly higher than that in ACCF group [(3.1 ± 1.4) mm vs.(2.3 ± 0.9) mm,P ＜ 0.05].There was no statistically significant difference in JOA scores,neurological improvement rate between ACDF group and ACCF group.Two cases of cerebrospinal fluid leakage in ACDF group,the oppression and drainage recovery after treatment.One case of 14 d after fistula complications in ACCF group,after patching were cured; 2 cases of titanium mesh shift,follow the fusion.Conclusions Both methods attain good clinical results.ACDF combined with ACCF treatment of multi-segmental cervical spondylotic myelopathy,with shorter operation time,relatively less blood loss,and better restoration of cervical sagittal alignment.

Hipomagnesemia no pós-operatório de artrodese de coluna / Hypomagnesemia after spinal fusion

OBJETIVOS: Verificar a frequência de hipomagnesemia em pacientes pediátricos submetidos a artrodese de coluna, avaliando se há queda significativa nas dosagens de magnésio sérico nos períodos pré e pós-operatório, quais suas possíveis causas e quais as consequências clínicas para os pacientes. MÉTODOS: Estudo retrospectivo e descritivo dos pacientes admitidos em uma Unidade de Terapia Intensiva pediátrica no pós-operatório de artrodese de coluna, no período de 1º de março a 31 de agosto de 2011. Foram comparados os níveis de magnésio, fósforo, cálcio total e ionizado no pré-operatório com os valores encontrados após a admissão na Unidade de Terapia Intensiva. RESULTADOS: Foram incluídos 45 pacientes, com idade média de 13,1 anos. No pré-operatório, o valor médio do magnésio foi de 1,8±0,2 mg/dL, e no pós-operatório, de 1,4±0,2 mg/dL, o que demonstra uma queda significativa entre os dois períodos (p < 0,001). A frequência de hipomagnesemia foi de somente um paciente (2%) no pré-operatório para 31 (68%) no pós-operatório. Houve também queda significativa nos níveis de fósforo (p < 0,001) e cálcio total (p < 0,001). Houve correlação significativa entre a queda do magnésio e o volume de fluido recebido durante a cirurgia (p = 0,03), volume de transfusão sanguínea (p < 0,001) e número de vértebras fixadas (p < 0,05). Dos 31 pacientes com hipomagnesemia, sete (22%) apresentaram sintomas. CONCLUSÃO: Existe uma elevada frequência de hipomagnesemia em pacientes submetidos a artrodese de coluna. Ao realizar a dosagem do magnésio sérico no momento da admissão na Unidade de Terapia Intensiva, a reposição adequada pode ser prontamente iniciada, minimizando o risco de complicações.

OBJECTIVES: To determine the frequency of hypomagnesaemia in pediatric patients after spinal fusion, to verify whether postoperative magnesium levels were lower than preoperative levels and, if so, to identify possible causes and assess the clinical repercussions for patients. METHODS: This was a retrospective descriptive study of pediatric patients admitted to a pediatric intensive care unit (ICU) after spine fusion surgery, between March 1 and August 31, 2011. Preoperative magnesium, phosphorus and total and ionized calcium concentrations were compared with the results of tests conducted during the first 24 hours after admission to the ICU. RESULTS: A total of 45 patients were enrolled on the study. Median age was 13.1 years. Preoperative mean serum magnesium was 1.8±0.2 mg/dL and postoperative serum magnesium was 1.4±0.2 mg/dL, which was a significant reduction between the two periods (p < 0.001). The frequency of hypomagnesaemia rose from 1 patient (2%) in the preoperative period to 31 patients (68%) during the postoperative period. There were also significant reductions in concentrations of phosphorus (p < 0.001) and total calcium (p < 0.001). There was a significant correlation between magnesium reductions and the volume of fluids administered during the surgery (p = 0.03), transfused blood volume (p < 0.001) and number of vertebrae fused (p < 0.05). Seven of the 31 patients with hypomagnesemia exhibited symptoms (22%). CONCLUSION: There was an elevated frequency of hypomagnesemia in patients who underwent spinal fusion. Serum magnesium should be assayed when patients are admitted to the pediatric ICU, so appropriate supplementation can be initiated immediately, minimizing the risk of complications.

The effect of tranexamic acid in perioperative blood loss control and its safety assessment in old patients with multiple lumbar spinal stenosis / 中国医师进修杂志

Objective To investigate the efficacy and safety of tranexamic acid in perioperative blood loss in old patients with multi-level lumbar spinal stenosis.Methods From January 2009 to September 2010,a total of 68 consecutive patients with multi-level lumbar spinal stenosis ( ≥65 years old) underwent posterior decompression,internal fixation and bone graft fusion who were randomly divided into group A and group B with 34 patients in each.The patients in group A received tranexamic acid and the patients in group B received an equal volume of normal saline.The amounts of intraoperative blood loss,postoperative wound drainage,blood transfusion,the number of the patients needing blood transfusion and hemoglobin,fibrinogen,prothrombin time and so on were examined preoperatively and 24 hours postoperatively.All the patients were observed for the clinical symptoms of deep vein thrombosis.Results The amounts of intraoperative blood loss,postoperative wound drainage,blood transfusion and the number of the patients needing blood transfusion in group A were significantly decreased than those in group B[ (641.1 ± 128.4) ml vs.(780.1 ± 107.3) ml,(228.80 ± 52.07) ml vs.(345.50 ±42.16) ml,(1.02 + 1.56) U vs.(2.89 ± 1.76) U,16 cases vs.28 cases ],there were significant differences between two groups (P ＜ 0.05 ).As for the value of postoperative hemoglobin concentration in group A [ ( 104.00 ± 4.87) g/L ] was significantly higher than that in group B [ (92.20 + 5.47 ) g/L ] (P ＜ 0.05 ).There were no significant differences in the levels of fibrinogen,prothrombin time,and activated partial thromboplastin time between two groups (P ＞ 0.05).No deep vein thrombosis was found 7 days postoperatively.Conclusion Tranexamic acid can be effectively used in spine surgery in old patients with multi-level lumbar spinal stenosis without increasing the risk of venous thrombosis.

β-tricalcium Phosphate Seeded with Bone Marrow Mesenchymal Stem Cells as Bone Graft Substitute for Posterolateral Spinal Fusion / 中国康复理论与实践

@# ObjectiveTo evaluate whether β-tricalcium phosphate (β-TCP) combined with bone marrow mesenchymal stem cells (BMSCs) can be used for lumbar posterolateral spine fusion (PLF) instead of autogenous bone graft. Methods6 crab-eating macaques underwent bilateral PLF at L4-5, and divided into 3 groups that implanted β-TCP/BMSCs composite, autogenous bone, and β-TCP. Monkeys were sacrificed 12 weeks after implantation. Manual palpation, micro computed tomography, peripheral quantitative computed tomography (pQCT), and histology were used to assess bone formation. ResultsManual palpation showed that 75% of β-TCP/BMSCs composite group and autogenous group achieved solid spine fusion, whereas none of β-TCP group fused. Histological analysis showed that all of the β-TCP/BMSCs group achieved massive bone formation. Bone mineral density (BMD) evaluated with pQCT in the β-TCP/BMSCs group increased by additional new bone. Conclusionβ-TCP/BMSCs composite can be used for PLF instead of autogenous bone graft.

Accelerated L5-S1 Segment Degeneration after Spinal Fusion on and above L4-5 : Minimum 4-Year Follow-Up Results

OBJECTIVE: Many biomechanical and clinical studies on adjacent segment degeneration (ASD) have addressed cranial segment. No study has been conducted on caudal segment degeneration after upper segment multiple lumbar fusions. This is a retrospective investigation of the L5-S1 segment after spinal fusion at and above L4-5, which was undertaken to analyze the rate of caudal ASD at L5-S1 after spinal fusion on and above L4-5 and to determine that factors that might have influenced it. METHODS: The authors included 67 patients with L4-5, L3-5, or L2-5 posterior fusions. Among these patients, 28 underwent L4-5 fusion, 23 L3-5, and 16 L2-5 fusions. Pre- and postoperative radiographs were analyzed to assess degenerative changes at L5-S1. Also, clinical results after fusion surgery were analyzed. RESULTS: Among the 67 patients, 3 had pseudoarthrosis, and 35 had no evidence of ASD, cranially and caudally. Thirteen patients (19.4%) showed caudal ASD, 23 (34.3%) cranial ASD, and 4 (6.0%) both cranial and caudal ASD. Correlation analysis for caudal ASD at L5-S1 showed that pre-existing L5-S1 degeneration was most strongly correlated. In addition, numbers of fusion segments and age were also found to be correlated. Clinical outcome was not correlated with caudal ASD at L5-S1. CONCLUSION: If caudal and cranial ASD are considered, the overall occurrence rate of ASD increases to 50%. The incidence rate of caudal ASD at L5-S1 was significantly lower than that of cranial ASD. Furthermore, the occurrence of caudal ASD was found to be significantly correlated with pre-existing disc degeneration.