Classification of sagittal imbalance based on spinal alignment and compensatory mechanisms

Sagittal balance is an independent predictor of clinical outcomes in spinal care. Surgical treatment is challenging and jeopardized by frequent complications. Guidelines for surgical treatment are currently not based on a classification of the disease. A comprehensive classification of sagittal balance based on regional deformities and compensatory mechanisms combined in deformity patterns is proposed. Though the sagittal shape of the spine can change due to degeneration or trauma, correlations between sagittal shape parameters and pelvic incidence (PI) have been described. Pelvic incidence is not changed by degeneration, thus representing a permanent source of information on the original sagittal shape of the spine.One hundred and twenty-eight full-spine lateral standing radiographs of patients with different spinal conditions were evaluated and classified by one rater. One random subseries of 35 patients was evaluated by two raters for calculation of inter-rater agreement. Spinopelvic parameters were measured in all the radiographs. Internal validity of the classification system was evaluated comparing the values of regional sagittal parameters that distinguish one category from the others.Eight different patterns were identified regarding the site of the deformity and the presence of compensatory mechanisms: cervical, thoracic, thoracolumbar junction, lumbar, lower lumbar, global and pelvic kyphosis and normal sagittal alignment. Inter-rater agreement was almost perfect (κ = 0.963). Statistically significant differences were found comparing the means of selected sagittal spinopelvic parameters that conceptually divide pairs or groups of categories: C2-C7 SVA for cervical kyphosis vs all other patients, TK-PI mismatch for thoracic kyphosis vs all other patients, T11-L2 kyphosis for thoracolumbar kyphosis vs all other patients, global alignment (LL+TK-PI) and SVA for lumbar kyphosis vs global kyphosis and pelvic tilt for pelvic kyphosis vs lumbar, lower lumbar and global kyphosis.A comprehensive classification of sagittal imbalance is presented. This classification permits a better interpretation of the deformity and muscle forces acting on the spine, and helps surgical planning. Preliminary validation has been provided

Prone single-position extreme lateral interbody fusion (Pro-XLIF): preliminary results.

Abstract Background Single-position options for combined anterior and posterior fusion in the lumbar spine have been suggested to reduce the surgical time and improve the efficiency of operating room. Previous reports have focused on lateral decubitus single-position surgery. The goal of this study is to describe and evaluate the feasibility and safety of prone single-position extreme lateral interbody fusion (XLIF) with posterior fixation. Methods Design Pilot prospective non-randomized controlled study. Seven patients who underwent prone single-position XLIF and posterior fixation were evaluated (Pro-XLIF). A control group (Std-XLIF) was composed of ten patients who underwent XLIF in lateral decubitus and posterior fixation in prone position. All patients underwent interbody XLIF fusion at one level and posterior procedures at one or more levels. Duration of surgery, blood loss, complications, X-ray use and clinical outcomes were recorded. Results No major complications were observed in either group. Oswestry Disability Index, back pain and leg pain were improved in the Pro-XLIF group from 48.5, 7.7 and 8.5 to 14.5, 1.71 and 2.71, respectively, and in the Std-XLIF group from 50.8, 5.7 and 7.2 to 22.5, 3.7 and 2.5. The Pro-XLIF group had a longer time of preparation before incision (39 vs 26 min, ns), equal duration of the anterior procedure (65 vs 59 min, ns), shorter duration of surgery (133 vs 182 min, ns) and longer X-ray exposure time (102 vs 92 s, ns). The surgical technique is described. Conclusions Prone single-position XLIF is feasible and safe. In this preliminary report, the results are comparable to the standard technique. Graphic abstract These slides can be retrieved under Electronic Supplementary Material

Classification of degenerative segment disease in adults with deformity of the lumbar or thoracolumbar spine

Lumbar and thoracolumbar deformity in the adult is a condition with impairment of health status that can need surgical treatment. In contrast with adolescent deformity, where magnitude of the curve plays a significant role in surgical indication, the aspects relevant in adult deformity are pain and dysfunction that correlate with segment degeneration and imbalance. Previous classifications of adult deformity have been of little use for surgical planning.Chart review and classification of radiographic and clinical findings. A classification of degenerative disc disease based on distribution of diseased segments and balance status of the spine is presented.Four main categories are presented: Type I (limited nonapical segment disease), Type II (limited apical segment disease), Type III (extended segment disease--apical and nonapical), Type IV (imbalanced spine: IVa, sagittally imbalanced; IVb, sagittally and coronally imbalanced).Types I and II can be treated by fusion of a selective area of the curve. Type III needs fusion of all the extension of the coronal curve. Type IV usually needs aggressive corrective procedures, frequently including posterior tricolumnar osteotomies. This classification permits interpreting the extension and magnitude of the disease and can help establish a surgical plan regarding selective fusion and methods of sagittal correction. Future research is needed to validate the classification

Análise dinâmica de pontes para ferrovias de alta velocidade de acordo com o Eurocódigo 1 - parte 2, estudo de caso prático

Dissertação de mestrado em Engenharia Civil - Área de especialização: EstruturasEste trabalho foi realizado no âmbito da unidade curricular de Dissertação/Projeto de Engenharia Civil do Mestrado em Engenharia Civil, da Escola Superior de Tecnologia do Barreiro, do Instituto Politécnico de Setúbal, e trata-se da Dissertação de Mestrado para a obtenção do grau de Mestre. Este trabalho pretende fazer uma abordagem ao estado da arte no que respeita às pontes e aos viadutos em linhas ferroviárias para comboios de alta velocidade com especial atenção na análise dos efeitos dinâmicos e respetivos códigos europeus. Numa primeira fase, o estudo centrou-se na apresentação das principais soluções estruturais adotadas para este tipo de estruturas executadas na Europa identificando-se e descrevendo-se alguns dos parâmetros e características técnicas associadas à conceção. Em seguida foi feito um levantamento dos principais aspetos regulamentares relacionados com a dinâmica de pontes para tráfegos de alta velocidade recorrendo às mais recentes normas europeias, os Eurocódigos. Depois apresentam-se os aspetos e técnicas relacionadas com os principais modelos e metodologias numéricas desenvolvidos para a análise dinâmica de pontes para alta velocidade. Finalmente, foi efetuado o estudo de uma estrutura existente em território Nacional para permitir a verificação do cumprimento dos referidos códigos e a aplicabilidade da referida estrutura ao trafego real existente na Europa a operarem redes de alta velocidade.This work was performed within the course unit Dissertation / Civil Engineering Project of the Master in Civil Engineering, at Barreiro Technology School, Polytechnic Institute of Setúbal, it is the Master's Thesis for the degree of Master. This work intends to make an approach to the state of the art with regard to bridges and viaducts on railway lines for high-speed trains with special attention on the dynamic analysis and respective European codes effects. Initially, the study focused on the presentation of the main structural solutions adopted for this type of structures in Europe by identifying and describing some of the technical parameters and characteristics associated with design. Then it was made a review of the main regulatory aspects related to the dynamics of bridges for high-speed traffic using the latest European standards, Eurocodes. Next, aspects and techniques related presentation of the main models and numerical methods developed for the dynamic analysis of bridges to high speed. Finally, the study of an existing structure implemented in national territory was made to allow verification of compliance with these codes and the applicability of that structure to the existing real traffic in Europe operating in high-speed networks

Classification of Sagittal Imbalance Based on Spinal Alignment and Compensatory Mechanisms

Introduction Sagittal balance is an independent predictor of clinical outcomes in spinal care. Surgical treatment is challenging and jeopardized by frequent complications. Guidelines for surgical treatment are currently not based on a classification of the disease. A comprehensive classification of sagittal balance, based on regional deformities and compensatory mechanisms combined with deformity patterns is proposed. Though the sagittal shape of the spine can change due to degeneration or trauma, correlations between sagittal shape parameters and pelvic incidence (PI) have been described. Pelvic incidence is not changed by degeneration, thus representing a permanent source of information on the original sagittal shape of the spine. Material and Methods A total of 128 full-spine lateral standing radiographs of patients with different spinal conditions were evaluated and classified by one rater. One random subseries of 35 patients was evaluated by two raters for calculation of interrater agreement. Spinopelvic parameters were measured in all the radiographs. The internal validity of the classification system was evaluated comparing the values of regional sagittal parameters that distinguish one category from the others. Results Eight different patterns were identified regarding the site of the deformity and the presence of compensatory mechanisms: cervical, thoracic, thoracolumbar junction, lumbar, lower lumbar, global and pelvic kyphosis, and normal sagittal alignment. Interrater agreement was almost perfect (j = 0.963). Statistically significant differences were found comparing the means of selected sagittal spinopelvic parameters that conceptually divide pairs or groups of categories: C2-C7 SVA for cervical kyphosis versus all other patients, TK-PI mismatch for thoracic kyphosis versus all other patients, T11-L2 kyphosis for thoracolumbar kyphosis versus all other patients, global alignment (LL? TK-PI) and SVA for lumbar kyphosis versus global kyphosis, and pelvic tilt for pelvic kyphosis versus lumbar, lower lumbar, and global kyphosis. Conclusion A comprehensive classification of sagittal imbalance is presented. This classification permits a better interpretation of the deformity and muscle forces acting on the spine, and helps surgical planning. Preliminary validation has been provided

Classification of Degenerative Segment Disease in Adults with Deformity of the Lumbar or Thoracolumbar Spine

Introduction Lumbar and thoracolumbar deformity in the adult is a condition with impairment of health status that can need surgical treatment. In contrast with adolescent deformity, where magnitude of the curve plays a significant role in surgical indication, the aspects relevant in adult deformity are pain and dysfunction that correlate with segment degeneration and imbalance. Previous classifications of adult deformity have been of little use for surgical planning. Materials and Methods Chart review and classification of radiographic and clinical findings. A classification of degenerative disc disease based on distribution of diseased segments and balance status of the spine is presented. Results Four main categories are presented: Type I (limited nonapical segment disease), Type II (limited apical segment disease), Type III (extended segment disease: apical and nonapical), and Type IV (imbalanced spine: IVa, sagittally imbalanced; IVb, sagittally and coronally imbalanced). Conclusion Types I and II can be treated by fusion of a selective area of the curve. Type III needs fusion of all the extension of the coronal curve. Type IV usually needs aggressive corrective procedures, frequently including posterior tricolumnar osteotomies. This classification permits interpreting the extension and magnitude of the disease and can help establish a surgical plan regarding selective fusion and methods of sagittal correction. Future research is needed to validate the classification

Procedimientos quirúrgicos de los miembros de la Sociedad Española de Cirugía de la Mano (SECMA) para la artrosis trapecio-metacarpiana: Un examen de las tendencias de la práctica clínica actual

Objetivo El objetivo principal de este estudio fue determinar los diferentes enfoques terapéuticos empleados en la práctica clínica habitual entre los cirujanos de mano en España en el abordaje de la artrosis trapecio-metacarpiana (TMC). Material y Método Se desarrolló una encuesta de 15 ítems para determinar los patrones terapéuticos en la práctica clínica de los cirujanos de mano en España que tratan la artrosis TMC. Esa prueba piloto se distribuyó a través de un servicio de encuestas en línea profesional (SurveyMonkey). Resultados El 94% de los cirujanos de mano en España se basan en la intensidad de dolor referida por el paciente para tomar una decisión quirúrgica. El 75% los inmoviliza durante un periodo de 3 semanas tras la cirugía y solo el 36% de los encuestados evalúa la intensidad de dolor después de la cirugía. Conclusiones Esa encuesta proporciona datos valiosos en relación con los patrones terapéuticos de la práctica clínica actual en el tratamiento quirúrgico de la artrosis TMC en los cirujanos de mano españoles. Nivel de Evidencia Nivel V

Classification of coronal imbalance in adult scoliosis and spine deformity: a treatment-oriented guideline

In adult spinal deformity (ASD), sagittal imbalance and sagittal malalignment have been extensively described in the literature during the past decade, whereas coronal imbalance and coronal malalignment (CM) have been given little attention. CM can cause severe impairment in adult scoliosis and ASD patients, as compensatory mechanisms are limited. The aim of this paper is to develop a comprehensive classification of coronal spinopelvic malalignment and to suggest a treatment algorithm for this condition. This is an expert's opinion consensus based on a retrospective review of CM cases where different patterns of CM were identified, in addition to treatment modifiers. After the identification of the subgroups for each category, surgical planning for each subgroup could be specified. Two main CM patterns were defined: concave CM (type 1) and convex CM (type 2), and the following modifiers were identified as potentially influencing the choice of surgical strategy: stiffness of the main coronal curve, coronal mobility of the lumbosacral junction and degeneration of the lumbosacral junction. A surgical algorithm was proposed to deal with each situation combining the different patterns and their modifiers. Coronal malalignment is a frequent condition, usually associated to sagittal malalignment, but it is often misunderstood. Its classification should help the spine surgeon to better understand the full spinal alignment of ASD patients. In concave CM, the correction should be obtained at the apex of the main curve. In convex CM, the correction should be obtained at the lumbosacral junction. These slides can be retrieved under Electronic Supplementary Material

Successful correction of sagittal imbalance can be calculated on the basis of pelvic incidence and age

Introduction Sagittal imbalance is an independent predictor of outcome in adult degenerative spinal deformity. Restoration of sagittal spinopelvic parameters correlates with a better postoperative outcome. Several methods of preoperative calculation for sagittal correction have been proposed, most of them geometrical. A nongeometrical method, based on data of spinopelvic relationships in normal subjects, that uses the patient's pelvic incidence and age to calculate target lumbar lordosis and thoracic kyphosis is proposed. The goal of this study is to describe and validate this nongeometrical method in terms of sensitivity and specificity to predict satisfactory spinopelvic alignment. Materials and Methods A retrospective cohort study of patients operated for sagittal imbalance with pedicle subtraction osteotomies (PSO). Two calculation algorithms (method a: LL = −[32.56 + PI × 0.54], method b: LL = −[PI + 10 degrees]); in both TK = PI/r (see text for definitions) obtain theoretical lumbar lordosis (LL) and thoracic kyphosis (TK) solely based on pelvic incidence and age, for surgical planning. The sample is categorized according to two parameters: planning goals (LL and TK) achieved or not and satisfactory alignment (SVA < 50 mm and PT < 20 degrees) achieved or not. Two × two tables are built and odds ratio, sensitivity and specificity and PPV/NPV are calculated for each planning method. Different levels of tolerance for undercorrection are analyzed to refine the use of the method. Results Of the 50 patients included in the study, 23 presented satisfactory alignment postoperatively. With a tolerance of hypocorrection of 10 degrees (LL) and 30 degrees (TK), correction target was achieved in 23 patients according to method a (S = 0.89, Sp = 0.87%, OR = 53.33 [95% CI: 9.677–293.931]; p < 0.001), 23 patients according to method b (S = 0.93, Sp = 0.91, OR = 131.25 [95% CI:17–1013]; p < 0.001). The best prediction of satisfactory alignment was obtained with method b and tolerance 0 degrees (LL) and 10 degrees (TK). All patients with complete correction of LL (both methods) achieved good alignment. Overall, 22 of the 24 (91%) patients with less than 10 degrees of undercorrection of LL (method b) achieved good alignment. Conclusion Calculation of the target lordosis based only in the value of PI and age is a reliable method that can predict good outcomes in terms of alignment. The rule LL = −(PI + 10 degrees) is an easy to calculate and very effective method of planning for lumbar lordosis and good alignment can be expected with high confidence when the final lordosis is within 10 degree of undercorrection. Including TK in surgical planning can improve the results in terms of restoration of the less known "spinopelvic balance" parameter

Worldwide excellence in evidence

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