A protocol for recruiting and analyzing the disease-oriented Russian disc degeneration study (RuDDS) biobank for functional omics studies of lumbar disc degeneration.

Lumbar intervertebral disc degeneration (DD) disease is one of the main risk factors for low back pain and a leading cause of population absenteeism and disability worldwide. Despite a variety of biological studies, lumbar DD is not yet fully understood, partially because there are only few studies that use systematic and integrative approaches. This urges the need for studies that integrate different omics (including genomics and transcriptomics) measured on samples within a single cohort. This protocol describes a disease-oriented Russian disc degeneration study (RuDDS) biobank recruitment and analyses aimed to facilitate further omics studies of lumbar DD integrating genomic, transcriptomic and glycomic data. A total of 1,100 participants aged over 18 with available lumbar MRI scans, medical histories and biological material (whole blood, plasma and intervertebral disc tissue samples from surgically treated patients) will be enrolled during the three-year period from two Russian clinical centers. Whole blood, plasma and disc tissue specimens will be used for genotyping with genome-wide SNP-arrays, glycome profiling and RNA sequencing, respectively. Omics data will be further used for a genome-wide association study of lumbar DD with in silico functional annotation, analysis of plasma glycome and lumbar DD disease interactions and transcriptomic data analysis including an investigation of differential expression patterns associated with lumbar DD disease. Statistical tests applied in each of the analyses will meet the standard criteria specific to the attributed study field. In a long term, the results of the study will expand fundamental knowledge about lumbar DD development and contribute to the elaboration of novel personalized approaches for disease prediction and therapy. Additionally to the lumbar disc degeneration study, a RuDDS cohort could be used for other genetic studies, as it will have unique omics data. Trial registration number NCT04600544.

MIS-TLIF versus O-TLIF for single-level degenerative stenosis: study protocol for randomised controlled trial.

INTRODUCTION: Patients with symptomatic single-level combination of degenerative stenosis and low-grade spondylolisthesis are often treated by nerve root decompression and spinal fusion. The gold standard is traditional open decompression and fusion, but minimally invasive method is more and more prevailing. However, there is lack of high-quality studies comparing these two techniques in order to obtain the advantages and certain indications to use one of these methods. The current study includes clinical, safety and radiological endpoints to determine the effectiveness of minimally invasive decompression and fusion (MIS-TLIF) over the traditional open one (O-TLIF). METHODS AND ANALYSIS: All patients aged 40-75 years with neurogenic claudication or bilateral radiculopathy caused by single-level combination of degenerative stenosis and low-grade spondylolisthesis, confirmed by MRI with these symptoms persisting for at least 3 months prior to surgery, are eligible. Patients will be randomised into MIS-TLIF or traditional O-TLIF. The primary outcome measure is Oswestry Disability Index at 3-month follow-up term. The secondary outcomes are patient-reported outcome measures by the number of clinical scales, radiological parameters including sagittal balance parameters, safety endpoints and cost-effectiveness of each method. All patients will be analysed preoperatively, as well as on the 14th day of hospital stay (or on the day of hospital discharge), 3 months, 6 months, 12 months and 24 months postoperatively. The study has the design of a parallel group to demonstrate the non-inferior clinical results of MIS-TLIF compared with the traditional O-TLIF. ETHICS AND DISSEMINATION: The study will be performed according to Helsinki Declaration. The study protocol was approved by the Local Ethical Committee of Priorov National Medical Research Center of Traumatology and Orthopedics in August 2020. Preliminary and final results will be presented in peer-reviewed journals, especially orthopaedic and spine surgery journals, at national and international congresses. TRIAL REGISTRATION NUMBER: NCT04594980.

Aspects of the use of propensity score matching methods in neurosurgery / Aspectos do uso dos métodos de pareamento de escore de propensão em neurocirurgia / Aspectos del uso de los métodos de emparejamiento de puntaje de propensión en neurocirugía

ABSTRACT Objective Observational studies and register data provide researchers with ample opportunities to obtain answers to questions that randomized controlled trials cannot answer for organizational or ethical reasons. One of the most common tools for solving this problem is the use of propensity score matching (PSM) methods. The purposes of our study were to compare various models and algorithms for selecting PSM parameters, using retrospective clinical data, and to compare the results obtained using the PSM method with those of prospective studies. Methods The results of two studies (randomized prospective and retrospective) conducted at the Novosibirsk Research Institute of Traumatology and Orthopedics were used for comparative analysis. The trials aimed to study the effectiveness and safety of surgical treatment of degenerative dystrophic lesions in the lumbar spine. We compared the results using the recommended PSM parameters (caliper=0.2 and 0.6) the propensity score is the probability of assignment to one treatment conditional on a subject's measured baseline covariates. Propensity-score matching is increasingly being used to estimate the effects of exposures using observational data. In the most common implementation of propensity-score matching, pairs of treated and untreated subjects are formed whose propensity scores differ by at most a pre-specified amount (the caliper widthand the caliper values often used in real-life studies (0.05, 0.1, 0.25, 0.5, and 0.8) with the those obtained in a similar prospective study. Results After eliminating systematic selection bias, the results of the retrospective and randomized prospective studies were qualitatively comparable. Conclusion The results of this study provide recommendations for the use of PSM: when evaluating efficacy scores in neurosurgical studies (with a sample size < 150 patients), we recommend matching on the logit of the propensity score using calipers of width equal to 0.6 of the standard deviation of the logit of the propensity score. Level of evidence V; Type of study is expert opinion.

RESUMO Objetivos Estudos observacionais e dados de registro fornecem aos pesquisadores amplas oportunidades de obter respostas às perguntas que os estudos clínicos randomizados não podem responder por razões institucionais ou éticas. Uma das ferramentas mais comuns para resolver esse problema é o uso dos métodos de Propensity Score Matching (PSM, pareamento de escore de propensão). O objetivo do nosso estudo foi comparar vários modelos e algoritmos para a seleção de parâmetros de PSM, usando os dados clínicos retrospectivos e comparar os resultados obtidos com esse método com os de estudos prospectivos. Métodos Os resultados de dois estudos (randomizado prospectivo e retrospectivo), realizados no Instituto de Pesquisa de Traumatologia e Ortopedia de Novosibirsk, foram utilizados para análise comparativa. Os estudos visaram estudar a eficácia e a segurança do tratamento cirúrgico de lesões distróficas degenerativas na coluna lombar. Comparamos os resultados usando os parâmetros recomendados pelo PSM, isto é calibração (caliper) de 0,2 e 0,6 e os valores de calibração usados com frequência em estudos da vida real (0,05, 0,1, 0,25, 0,5 e 0,8) com os obtidos em um estudo prospectivo semelhante. Resultados Depois de eliminar o viés sistemático de seleção, os resultados de estudos randomizados prospectivos e retrospectivos foram qualitativamente comparáveis. Conclusões Os resultados deste estudo fornecem recomendações para o uso do PSM: ao avaliar os escores de eficácia em estudos neurocirúrgicos (com tamanho de amostra < 150 pacientes), recomendamos a correspondência do logit do escore de propensão com calibração de largura de 0,6 do desvio padrão do logit do escore de propensão. Nível de evidência V; Opinião do especialista.

RESUMEN Objetivos Los estudios de observación y los datos de registro brindan a los investigadores amplias oportunidades para obtener respuestas a preguntas que los estudios clínicos aleatorizados no pueden responder por razones institucionales o éticas. Una de las herramientas más comunes para resolver este problema es el uso de los métodos de Propensity Score Matching (PSM, emparejamiento de puntaje de propensión). El objetivo de nuestro estudio fue comparar varios modelos y algoritmos para la selección de parámetros de PSM, utilizando los datos clínicos retrospectivos y comparar los resultados obtenidos con ese método con los de estudios prospectivos. Métodos Los resultados de dos estudios (prospectivo aleatorizado y retrospectivo) realizados en el Instituto de Investigación de Traumatología y Ortopedia de Novosibirsk se utilizaron para el análisis comparativo. Los estudios tuvieron como objetivo estudiar la eficacia y seguridad del tratamiento quirúrgico de las lesiones distróficas degenerativas en la columna lumbar. Comparamos los resultados usando los parámetros recomendados por el PSM, esto es, calibración (caliper) de 0,2 y 0,6 y los valores de calibración usados con frecuencia en estudios de la vida real (0,05, 0,1, 0,25, 0,5 y 0,8) con los obtenidos en un estudio prospectivo semejante. Resultados Después de eliminar el sesgo sistemático de selección, los resultados de estudios prospectivos aleatorizados y retrospectivos fueron cualitativamente comparables. Conclusiones Los resultados de este estudio proporcionan recomendaciones para el uso del PSM: al evaluar los puntajes de eficacia en estudios neuroquirúrgicos (con tamaño de muestra <150 pacientes), recomendamos la correspondencia del logit del puntaje de propensión con calibración de ancho de 0.6 de la desviación estándar del logit de puntaje de propensión. Nivel de evidencia V; Opinión del especialista.

Predictors of Treatment Success Following Limited Discectomy With Annular Closure for Lumbar Disc Herniation.

BACKGROUND: Previous studies have demonstrated bone-anchored annular closure to significantly reduce reherniation and reoperation rates after lumbar discectomy in patients with large annular defects. It is important to identify the prognostic factors that may be associated with successful treatment. This study aimed to identify predictors of treatment success in patients with lumbar disc herniation treated with limited microdiscectomy supplemented by a bone-anchored annular closure device (ACD). METHODS: This study was a retrospective analysis of 133 consecutive patients with lumbar disc herniation treated with the ACD. Treatment success was defined as ≥24% improvement in visual analog scale (VAS) for back pain, ≥39% improvement in VAS leg pain, and ≥33% in the Oswestry Disability Index (ODI), with the raw ODI score ≤48. Success was calculated at 3, 6, and 12 months after surgery. Potentially predictive outcomes included patient characteristics, operative data, and imaging outcomes, such as disc, facet, and end plate morphology. Logistic regression was used to determine the significant predictive factors for treatment success. RESULTS: After 3, 6, and 12 months, 97 of 131 (74%), 104 of 129 (81%), and 112 of 126 (89%) patients, respectively, achieved the success criteria. At 3 months follow-up, a higher proportion of younger (17-40 years) versus older (41-65 years) patients met the success criteria (P = .025). On the basis of logistic regression, the following factors were significantly associated with treatment success at 1 or more of the follow-up time points: sex (male), lower body mass index, higher baseline pain and ODI scores, lower grade preoperative disc degeneration, and the absence of a postoperative complication. The rates of index-level recurrent herniation and reoperation were 1.5% and 3.0%, respectively. CONCLUSIONS: This real-world evidence supports a promising benefit-risk profile for augmenting limited microdiscectomy with a bone-anchored ACD and provides some insights into the patient populations that may have a greater chance of realizing significant improvements in pain and function. LEVEL OF EVIDENCE: 2 (Cohort study).

The importance of psychological testing in predicting the effectiveness of lumbar spine surgery / A importância do teste psicológico na previsão da eficácia da cirurgia da coluna lombar / La importancia de las pruebas psicológicas en la predicción de la efectividad de la cirugía de la columna lumbar

ABSTRACT Objective: The result of treatment of patients with degenerative disc diseases is partly determined by the psychological characteristics of the patients. The aim of this study was to examine the correlations between the psychological scales scores in patients with degenerative lumbar disc diseases and the effectiveness of surgical treatment. Methods: The efficacy of the operation and patients' satisfaction were compared with the preoperative psychological characteristics, according to the questionnaires and scales (BBQ Symonds, Zung Scale, FABQ, PCI, BBQ Catastrophization). Results: In patients with neurogenic intermittent claudication syndrome without significant pain, the operative treatment depended significantly on the value of the BBQ Symonds scale (p = 0.016). In patients with severe radicular pain in the lower extremity, the effectiveness of the operation depended significantly on the value of the subscale "protection" of the PCI questionnaire (p = 0.04), the ODI index filled out before the operation (p = 0.0). In patients with lumbar syndrome, the effectiveness of operation depended significantly on the value of the PCI questionnaire as a whole (p = 0.042) and its subscores "rest" (p = 0.028), the index of the Oswestry filled out before the operation (p = 0.035). Conclusion: The effectiveness of the operation of degenerative lumbar disc diseases is associated with the results of preoperative psychological testing. It has been established that the BBQ Symonds scale, PCI protection and rest subscales, and the ODI questionnaire are the most significant; these psychological scales have the power to predict the effectiveness of surgical treatment. Level of Evidence II; Therapeutic Study - Investigating the Results of Treatment.

RESUMO Objetivo: O resultado no tratamento de pacientes com doenças degenerativas do disco é parcialmente determinado pelas características psicológicas dos pacientes. O objetivo do estudo foi examinar as correlações entre as escalas de índice psicológico em pacientes com doenças degenerativas do disco lombar e a eficácia do tratamento cirúrgico. Métodos: A eficácia da operação e a satisfação dos pacientes foram comparadas com as características psicológicas pré-operatórias, de acordo com os questionários e escalas (BBQ Symods, Zung Scale, FABQ, PCI, Catastrofización de BBQ). Resultados: Em pacientes com a síndrome de claudicação neurogênica intermitente sem dor significativa, o tratamento cirúrgico dependeu significativamente do valor da escala BBQ Symods (p = 0,016). Em pacientes com dor radicular grave no membro inferior, a eficácia da operação dependeu significativamente do valor da "proteção" da subescala do questionário de ICP (p = 0,04), preenchido antes da operação pelo índice ODI (p = 0,0). Nos pacientes com síndrome lombar, a eficácia da operação dependia significativamente do valor do questionário PCI como um todo (p = 0,042) e seu subscore "repouso" (p = 0,028) e o índice do Oswestry preenchido antes da operação (p = 0,035). Conclusão: A efetividade do funcionamento das doenças degenerativas do disco lombar está associada aos resultados dos testes psicológicos pré-operatórios. Foi estabelecido que a escala BBQ Symods, subescalas de proteção e descanso de PCI e o questionário de ODI são mais significativos; essas escalas psicológicas têm poder preditivo em relação à eficácia do tratamento cirúrgico. Nível de Evidência II; Estudo Terapêutico - Investigação dos resultados do tratamento.

RESUMEN Objetivo: El resultado del tratamiento de pacientes con enfermedades degenerativas del disco está parcialmente determinado por las características psicológicas de los pacientes. El objetivo del estudio fue examinar las correlaciones entre las escalas de índice psicológico en pacientes con enfermedades degenerativas del disco lumbar y la efectividad del tratamiento quirúrgico. Métodos: Se comparó la eficacia de la operación y la satisfacción de los pacientes con las características psicológicas preoperatorias según los cuestionarios y escalas (BBQ Symonds, Zung Scale, FABQ, PCI, Catastrofización de BBQ). Resultados: En pacientes con síndrome de claudicación neurogénica intermitente sin dolor significativo, el tratamiento quirúrgico dependió significativamente del valor de la escala BBQ Symonds (p = 0,016). En pacientes con dolor radicular severo en la extremidad inferior, la efectividad de la operación dependió significativamente del valor de la subescala "protección" del cuestionario PCI (p = 0,04), el índice ODI llenado antes de la operación (p = 0,0). En pacientes con síndrome lumbar, la efectividad de la operación dependió significativamente del valor del cuestionario PCI como un todo (p = 0,042) y sus subcategorías "reposo" (p = 0,028), el índice de Oswestry llenado antes de la operación (p = 0,035). Conclusión: La efectividad de la operación de las enfermedades degenerativas del disco lumbar se asocia con los resultados de las pruebas psicológicas preoperatorias. Se ha establecido que la escala de BBQ Symonds, las subescalas de protección y reposo PCI y el cuestionario ODI son los más significativos; estas escalas psicológicas tienen poder predictivo en relación con la efectividad del tratamiento quirúrgico. Nivel de Evidencia II; Estudio Terapéutico - Investigación de los resultados del tratamiento.