Coluna/ Columna最新文献_第10页

OSTEOPOROTIC SPINE FRACTURES TREATED WITH KYPHOPLASTY OR VERTEBROPLASTY: A META-ANALYSIS 后凸成形术或椎体成形术治疗骨质疏松性脊柱骨折:一项荟萃分析

Coluna/ Columna Pub Date : 2022-01-01 DOI: 10.1590/s1808-185120222102257080

Raimundo Fabricio Seade Vieira, Isabella Guirelli Santana, Daniel Pereira Rezende de Almeida, Luciano Elias Barboza, Fernando William Figueiredo da Rosa

{"title":"OSTEOPOROTIC SPINE FRACTURES TREATED WITH KYPHOPLASTY OR VERTEBROPLASTY: A META-ANALYSIS","authors":"Raimundo Fabricio Seade Vieira, Isabella Guirelli Santana, Daniel Pereira Rezende de Almeida, Luciano Elias Barboza, Fernando William Figueiredo da Rosa","doi":"10.1590/s1808-185120222102257080","DOIUrl":"https://doi.org/10.1590/s1808-185120222102257080","url":null,"abstract":"ABSTRACT Kyphoplasty (KP) and vertebroplasty (VP) are both widely adopted treatments for patients with osteoporotic vertebral fractures (OVF), however, which of these techniques is more effective has not yet been established. We performed a systematic review of articles, followed by meta-analysis, in an attempt to establish the differences between KP and VP. Initially, 187 articles were obtained, 20 of which were systematically reviewed and submitted to meta-analysis. Thus, 2,226 patients comprised the universe of the present article, 1202 of whom underwent KP and 1024 of whom underwent VP. The statistically significant results observed included lower mean bone cement leakage (ml) in the group submitted to kyphoplasty, with OR: 1.50 [CI95%: 1.16 - 1.95], p <0.05; shorter mean surgical time (minutes), 0.45 [CI90% 0.08 - 0.82], p <0.1, for the group submitted to VP as compared to the KP group; and a lower mean postoperative Oswestry Disability Index score in the KP group, OR: −0.14 [CI95%: −0.28 - 0.01], p <0.05. KP was more effective in improving physical function and had a lower frequency of cement leakage when compared to VP, although it requires longer surgical time. Level of evidence III; Systematic review of level III studies.","PeriodicalId":40025,"journal":{"name":"Coluna/ Columna","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67479242","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

ANATOMIC AND FUNCTIONAL ANALYSIS OF THORACIC KYPHOSIS AND LUMBAR LORDOSIS 胸后凸和腰椎前凸的解剖和功能分析

Coluna/ Columna Pub Date : 2022-01-01 DOI: 10.1590/s1808-185120222102263305

R. Meves, M. Defino, Guilherme do Amaral Mussatto, Guilherme Pianowski Pajanoti

引用次数: 0

ANALYSIS OF PATIENTS SUBMITTED TO SURGICAL TREATMENT FOR NEUROMUSCULAR SCOLIOSIS WITH AND WITHOUT INTRAOPERATIVE TRACTION 手术治疗神经肌肉性脊柱侧凸患者有无术中牵引的分析

Coluna/ Columna Pub Date : 2022-01-01 DOI: 10.1590/s1808-185120222103262614

B. Nunes, D. Zanotto, Christiano Cruz Lima, Germano Senna, L. T. P. E. Silva, J. Nascimento, C. Reis, Bruno Pinto Coelho Fontes

{"title":"ANALYSIS OF PATIENTS SUBMITTED TO SURGICAL TREATMENT FOR NEUROMUSCULAR SCOLIOSIS WITH AND WITHOUT INTRAOPERATIVE TRACTION","authors":"B. Nunes, D. Zanotto, Christiano Cruz Lima, Germano Senna, L. T. P. E. Silva, J. Nascimento, C. Reis, Bruno Pinto Coelho Fontes","doi":"10.1590/s1808-185120222103262614","DOIUrl":"https://doi.org/10.1590/s1808-185120222103262614","url":null,"abstract":"ABSTRACT Objectives: To compare the surgical treatment of neuromuscular scoliosis (NMS) with and without intraoperative skull-skeletal traction (ISST) in terms of the degree of curve correction, surgical time, hospitalization time, screw density, use of blood products,and complications. Methods: A comparative retrospective study, in which we analyzed the medical records and radiographs of 17 patients who underwent surgical treatment for neuromuscular scoliosis (NMS). They were divided into two groups, with 9 and 8 patients operated with and without ISST, respectively, at a referral hospital specialized in the treatment of spinal deformitiesfrom 2019 to 2021. The categorical variables were analyzed using the Chi-squared test. Results: Among the 17 patients included in the study, there was a higher prevalence of women in the group without ISST (6 and 2) and of men in group with ISST (5 and 3). The ages of the patients in the two groups ranged from 8-19 years and from 11-29 years, respectively. The screw density used in the traction group averaged 66.33%±8.49 and 82.63%±17.25 in the non-traction group, a statistically significant differencewith a P-value of 0.036. The average percent correction was 76.81%±15.61 in the traction group as compared to an average of 66.39%±12.99 in the non-traction group. In addition, there were complications in 1 patient in each of the groups. Conclusions: Surgical treatment for NMS with ISST allows surgery using fewer blood products to maintain the same hematimetric level in the postoperative period. ISST also allows the use of a lower screw density to correct more severe deformities. Level of evidence III; Comparative retrospective study.","PeriodicalId":40025,"journal":{"name":"Coluna/ Columna","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67479882","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

RELATIONSHIP BETWEEN VERTEBRAL VESSELS AND CORTICAL PATH SCREWS IN CORTICAL TRANSFIXATION 皮质内穿固定中椎血管与皮质路径螺钉的关系

Coluna/ Columna Pub Date : 2022-01-01 DOI: 10.1590/s1808-185120222101250506

Renato de Melo Guimarães, Rogério Lúcio Chaves de Resende, Jefferson Soares Leal, Luiz Claudio de Moura França, Guilherme Ribeiro Almeida

{"title":"RELATIONSHIP BETWEEN VERTEBRAL VESSELS AND CORTICAL PATH SCREWS IN CORTICAL TRANSFIXATION","authors":"Renato de Melo Guimarães, Rogério Lúcio Chaves de Resende, Jefferson Soares Leal, Luiz Claudio de Moura França, Guilherme Ribeiro Almeida","doi":"10.1590/s1808-185120222101250506","DOIUrl":"https://doi.org/10.1590/s1808-185120222101250506","url":null,"abstract":"ABSTRACT Introduction: This study aims to evaluate the safety of using the cortical path screw with transfixation of the second cortical bone in relation to the vascular structures. Methods: This retrospective observational study (level of evidence: III, study of non-consecutive patients) analyzed data from the medical records of patients who underwent computed angiotomography scans of the abdomen at Hospital Mater Dei, measuring, in millimeters, the distance between the point of the lumbar vertebra considered the anatomical reference for the transfixation of the second cortical bone and the vascular structures adjacent to the spine (abdominal aorta, inferior vena cava, iliac vessels, segmental lumbar arteries). Results: Forty-eight patients were evaluated, with a mean age of 60 years (±8 years, 41-75), of whom 52% were male and 48% female. The measurements obtained between the pre-vertebral vessels and the possible screw exit points did not demonstrate contact in any of the vertebrae studied. Conclusions: The measurements obtained suggest the safety of using the cortical path screw transfixing the second cortical bone. Knowing the position of the vessels is essential to reduce intra- and postoperative complications related to spinal instrumentation. Level of evidence III; Study of non-consecutive patients.","PeriodicalId":40025,"journal":{"name":"Coluna/ Columna","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67478335","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

PERCUTANEOUS CEMENT DISCOPLASTY IN THE TREATMENT OF DEGENERATIVE DISC DISEASE. CASE SERIES 经皮骨水泥椎间盘成形术治疗退行性椎间盘疾病。案例系列

Coluna/ Columna Pub Date : 2022-01-01 DOI: 10.1590/s1808-185120222101259477

Dittmar-Johnson Herman Michael, Cruz Francisco, González-Camacho Eduardo, Chavarreti-Gutiérrez Oscar Mikhail, Tejera-Morett Alejandro, Sánchez-García Francisco Javier, De Haro-Estrada Jorge, Larios-Bejar Marco Antonio

{"title":"PERCUTANEOUS CEMENT DISCOPLASTY IN THE TREATMENT OF DEGENERATIVE DISC DISEASE. CASE SERIES","authors":"Dittmar-Johnson Herman Michael, Cruz Francisco, González-Camacho Eduardo, Chavarreti-Gutiérrez Oscar Mikhail, Tejera-Morett Alejandro, Sánchez-García Francisco Javier, De Haro-Estrada Jorge, Larios-Bejar Marco Antonio","doi":"10.1590/s1808-185120222101259477","DOIUrl":"https://doi.org/10.1590/s1808-185120222101259477","url":null,"abstract":"ABSTRACT Introduction: Percutaneous cement discoplasty (PCD) is a minimally invasive surgical technique, which provides segmental stabilization and an indirect decompression effect in cases of severe degenerative disc disease with vacuum phenomenon, useful in patients with comorbidities that contraindicate invasive surgical procedures. Materials and methods: A retrospective analysis of 6 patients undergoing PCD was carried out, reporting the demographic variables, the segments treated and the clinical result evaluated by means of the visual analog pain scale (VAS) both in the presurgical and in the 6-month follow-up. Finally, a literature review was carried out. Results: 6 cases of PCD were included, of which 5 had a diagnosis of dyscarthrosis and 1 dyscarthrosis with spondylolisthesis. 4 female and 2 male patients. In 3 patients, PCD was performed in 1 segment and in 3 patients in multiple segments. Regarding the clinical result, an improvement was presented in 5 of the patients (mean 5.6 VAS points), 1 of the patients did not present improvement and required another surgical intervention. Conclusions: PCD is a minimally invasive technique useful in the treatment of spine pain secondary to degenerative disc disease in those patients with comorbidities that contraindicate a major procedure. Indirect foraminal decompression by PCD in one or more segments appears to contribute to pain relief. Level of Evidence III. Series of cases and controls.","PeriodicalId":40025,"journal":{"name":"Coluna/ Columna","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67478786","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

MORPHOLOGICAL ASPECT OF PYOGENIC SPINAL EPIDURAL ABSCESSES. PART I 化脓性脊髓硬膜外脓肿的形态学特征。第一部分

Coluna/ Columna Pub Date : 2022-01-01 DOI: 10.1590/s1808-185120222101260738

P. Bazán, J. C. S. Adaro, N. M. Ciccioli, A. O. G. Adaro, R. González

{"title":"MORPHOLOGICAL ASPECT OF PYOGENIC SPINAL EPIDURAL ABSCESSES. PART I","authors":"P. Bazán, J. C. S. Adaro, N. M. Ciccioli, A. O. G. Adaro, R. González","doi":"10.1590/s1808-185120222101260738","DOIUrl":"https://doi.org/10.1590/s1808-185120222101260738","url":null,"abstract":"ABSTRACT Background: Pyogenic Spinal Epidural Abscess (PSEA) is difficult to diagnose and can have devastating consequences. Magnetic Resonance Imaging (MRI) has high sensitivity and specificity, which are further increased with the use of contrast. There are several classifications of vertebral infectious processes, with emphasis on spondylodiscitis. Objective: To analyze the morphological parameters and their reproducibility; and to analyze different resonance imaging sequences. Methods: Using an image database, a morphological classification of PSEA was planned, with five parameters: Region (R), indicating the upper and lower limits of the abscess; Location (U), indicating whether the abscess is anterior or posterior within the canal; Compromise (C), meningeal or content of the structures; Association (A), discitis, osteomyelitis or both; and Perivertebral (P), anterior, lateral or posterior extravertebral abscess. The first three parameters give an idea of the volume of the PSEA, while the last two give the related infectious foci. Thirty-five cases were analyzed using Kappa’s coefficient. Results: The global intra- and interobserver reproducibility was Kappa 0.81. The results for each parameter were as follows: R=0.95, U=0.92, C=0.66, A=0.70 and P=0.80. The first three give a notion of volume and the last two relate to the presence of vertebral infectious foci outside the canal. T2 weighted MRI with contrast was found to be the most effective imaging sequence. Conclusion: The morphological classification is simple to use, with excellent reproducibility. The parameters with the highest reproducibility were region and location, with values >0.92. The addition of gadolinium contrast increased the sensitivity of the diagnosis; the use of sagittal and axial images in T2-MRI was the most sensitive imaging sequence. Evidence Level III; Original.","PeriodicalId":40025,"journal":{"name":"Coluna/ Columna","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67478865","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

EFFECT OF THE MAITLAND CONCEPT TECHNIQUES ON LOW BACK PAIN: A SYSTEMATIC REVIEW 大陆概念技术对腰痛的影响:系统回顾

Coluna/ Columna Pub Date : 2022-01-01 DOI: 10.1590/s1808-185120222102258429

Lidia Romero Outeda, Lorenzo Antonio Justo Cousiño, I. D. C. Carrera, E. M. L. Caeiro

{"title":"EFFECT OF THE MAITLAND CONCEPT TECHNIQUES ON LOW BACK PAIN: A SYSTEMATIC REVIEW","authors":"Lidia Romero Outeda, Lorenzo Antonio Justo Cousiño, I. D. C. Carrera, E. M. L. Caeiro","doi":"10.1590/s1808-185120222102258429","DOIUrl":"https://doi.org/10.1590/s1808-185120222102258429","url":null,"abstract":"ABSTRACT Low back pain has a prevalence that reaches up to 70% of the population between 35-55 years of age and is the principal cause of occupational disability. The scientific evidence on the effect of manual therapy on low back pain is conflicting and there are no specific reviews on the Maitland concept of manual therapy. Therefore, the objective of this systematic review is to analyze the effect of the techniques of the Maitland concept of manual therapy in patients with low back pain and/or determine the level of scientific evidence.For this, a search was carried out in the Cinahl, Medline, Web of Science, PubMed and Scopus databases during the months of January and February 2021 and it was updated in August 2021. In the search, 894 records were obtained, of which 15 randomized clinical trials that obtained a minimum of 3 points out of 5 on the Jadad scale were included.The main results in the current scientific literature suggest that there is solid evidence that the manipulations and mobilizations described in the Maitland Concept, applied alone or in combination with other interventions, reduce pain and disability in subjects with low back pain.The effects on musculature are contradictory. Exercise and patient education increase the effect of manual therapy. Future research requires analyzing whether the effects are preserved in the long term and more homogeneous treatment protocols are needed to determine a prescriptive guideline for manual therapy. Level of evidence I; Systematic review.","PeriodicalId":40025,"journal":{"name":"Coluna/ Columna","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67479179","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

VALIDATION OF MEASURING PI USING CT AND A COMPARISON WITH WHOLE SPINE AND LUMBOSACRAL X-RAYS 用ct测量PI的有效性以及与全脊柱和腰骶部x线的比较

Coluna/ Columna Pub Date : 2022-01-01 DOI: 10.1590/s1808-185120222102261465

M. Daher, R. Daher, Ricardo Tavares Daher, Lucas Lodomiro Melo, Wender Gonçalves Moura, Vinício Nunes Nascimento, Pedro Felisbino Jr, Ricardo Vieira Teles Filho, Juliane leite Orcino, M. Rabahi

{"title":"VALIDATION OF MEASURING PI USING CT AND A COMPARISON WITH WHOLE SPINE AND LUMBOSACRAL X-RAYS","authors":"M. Daher, R. Daher, Ricardo Tavares Daher, Lucas Lodomiro Melo, Wender Gonçalves Moura, Vinício Nunes Nascimento, Pedro Felisbino Jr, Ricardo Vieira Teles Filho, Juliane leite Orcino, M. Rabahi","doi":"10.1590/s1808-185120222102261465","DOIUrl":"https://doi.org/10.1590/s1808-185120222102261465","url":null,"abstract":"ABSTRACT Objective: The objective of this study is to describe a new, extremely simple method for measuring pelvic incidence (PI) using computed tomography (CT) and to compare those measurements with measurements derived from whole spine and lumbosacral X-rays in a Brazilian population. Methods: Patients who had whole spine and lumbosacral X-rays and whole abdomen, pelvis, or lumbar spine CT performed within a period of less than three months were selected. Image overlay was used to measure PI from the CT. The PI was calculated by two independent examiners, and the PI for each exam was calculated twice, with an interval of two months between the assessments. The intra- and interexaminer reliability and reproducibility were evaluatedusing the intraclass correlation coefficient (ICC) and the repeatability coefficient, considering a 95% confidence interval. Results: Fifty-five patients of both sexes with a mean age of 58.7 years (±19) were analyzed. The mean PI angles in the analyses of both examiners at both evaluations were 54.85° (±13.73) for the whole spine X-ray, 54.06° (±11.67) for the lumbosacral spine X-ray, and 49.96° (±9.85) for the CT. There was good intra- and interexaminer reliability and reproducibility. There was also high concordancewith the whole spine and lumbosacral X-rays. Conclusion: CT is a reliable and reproducible alternative for measuring PI. Level of Evidence III; Prospective comparative.","PeriodicalId":40025,"journal":{"name":"Coluna/ Columna","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67479218","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

FINITE ELEMENT ANALYSIS OF THORACIC VERTEBRAL STABILITY SUPPORTED BY THE FOURTH SPINE 第四节脊柱支撑胸椎稳定性的有限元分析

Coluna/ Columna Pub Date : 2022-01-01 DOI: 10.1590/s1808-185120222104266858

Javier Andrés Martínez Silva, Alan Rojas Ayala, Carlos Josué Victoria Buitimea, Edgardo Leon Salguero, Myrna Cosette Valenzuela Beltran

{"title":"FINITE ELEMENT ANALYSIS OF THORACIC VERTEBRAL STABILITY SUPPORTED BY THE FOURTH SPINE","authors":"Javier Andrés Martínez Silva, Alan Rojas Ayala, Carlos Josué Victoria Buitimea, Edgardo Leon Salguero, Myrna Cosette Valenzuela Beltran","doi":"10.1590/s1808-185120222104266858","DOIUrl":"https://doi.org/10.1590/s1808-185120222104266858","url":null,"abstract":"ABSTRACT Objective: In traumatic injuries of the thoracic spine, three variables are analyzed to make decisions: morphology of the injury, posterior ligamentous complex and neurological status; currently the fourth column is not evaluated; our objective was to determine the biomechanical behavior of the spine with a fracture of the fifth thoracic vertebral body when accompanied by a short oblique fracture of the sternum. Methods: An anonymous model of a healthy 25-year-old male was used, from which the thoracic spine and rib cage were obtained; in addition to the ligaments of the posterior complex and the intervertebral discs, four models were simulated. An axial section was made, a load of 400 N was applied, and the biomechanical behavior of each model was determined. Results: The area that suffered the most stress at the vertebral level was the posterior column of T4-T5 (tensile strength of 747 MPa), which exceeded the plastic limit, the load through the ribs was distributed from the first to the sixth (100 MPa), in the sternum the stress increased (200 MPa), the deformity increased to 45 mm. Conclusions: The sternum was a fundamental part of the spine’s stability; the combined injury severely increased the stress (8 MPa to 747 MPa) in the spine and exceeded the plastic limit, which generated an instability that is represented by the global deformity acquired (1 mm to 45 mm). Level of evidence II; Prospective comparative study.","PeriodicalId":40025,"journal":{"name":"Coluna/ Columna","volume":"124 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67480273","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

AN ANESTHESIA SUGGESTION FOR ENDOSCOPIC LUMBAR SPINE SURGERY 内镜下腰椎手术的麻醉建议

Coluna/ Columna Pub Date : 2021-12-01 DOI: 10.1590/s1808-185120212004257486

J. Abrão, H. R. D. Costa, Alexandre Cubas da Silva, Edgar Takao Utino, J. P. Bergamaschi

引用次数: 0