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1.
Orthop Surg ; 9(3): 311-318, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28960815

RESUMO

OBJECTIVE: To investigate the effect of asymmetric tension on idiopathic scoliosis (IS) and to understand its pathogenic mechanism. METHODS: The rodent model of scoliosis was established using Sprague-Dawley rats with left rib-tethering from T6 to T12 , tail and shoulder amputation, and high-cage feeding. Vertebrae epiphyseal cartilage plates were harvested from the convex and concave sides. To analyze differences on the convex and concave sides, finite element analysis was carried out to determine the mechanical stress. Protein expression on epiphyseal cartilage was evaluated by western blot. Micro-CT was taken to evaluate the bone quality of vertebral on both sides. RESULTS: Scoliosis curves presented in X-ray radiographs of the rats. Finite element analysis was carried out on the axial and transverse tension of the spine. Stresses of the convex side were -170.14, -373.18, and -3832.32 MPa (X, Y, and Z axis, respectively), while the concave side showed stresses of 361.99, 605.55, and 3661.95 MPa. Collagen type II, collagen type X, Sox 9, RunX2, VEGF, and aggrecan were expressed significantly more on the convex side (P < 0.05). There was asymmetric expression of protein on the epiphyseal cartilage plate at molecular level. Compared with the convex side, the concave side had significantly lower value in the BV/TV and Tb.N, but higher value in the Tb.Sp (P < 0.05). There was asymmetry of bone quality in micro-architecture. CONCLUSIONS: In this study, asymmetric tension contributed to asymmetry in protein expression and bone quality on vertebral epiphyseal plates, ultimately resulting in asymmetry of anatomy. In addition, asymmetry of anatomy aggravated asymmetric tension. It is the first study to show that there is an asymmetrical vicious circle in IS.


Assuntos
Lâmina de Crescimento/fisiopatologia , Escoliose/fisiopatologia , Animais , Fenômenos Biomecânicos , Western Blotting , Osso Esponjoso/diagnóstico por imagem , Osso Esponjoso/patologia , Modelos Animais de Doenças , Feminino , Análise de Elementos Finitos , Lâmina de Crescimento/diagnóstico por imagem , Lâmina de Crescimento/metabolismo , Proteínas/metabolismo , Ratos Sprague-Dawley , Escoliose/diagnóstico por imagem , Escoliose/metabolismo , Escoliose/patologia , Coluna Vertebral/diagnóstico por imagem , Coluna Vertebral/patologia , Coluna Vertebral/fisiopatologia , Estresse Mecânico , Microtomografia por Raio-X/métodos
2.
Orthop Surg ; 6(4): 294-9, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25430713

RESUMO

OBJECTIVE: To evaluate the clinical use of kinetic magnetic resonance imaging (kMRI) in spinal degenerative diseases. METHODS: A systematic search of PubMed, EMBASE and ISI databases for articles that had been published between January 1978 and February 2013 concerning patients who had undergone kMRI for spinal problems was performed. All selected patients had undergone kMRI in neutral, flexion, and extension weight-bearing positions. Evaluation of cervical and lumbar degeneration by kMRI was analyzed. kMRI showed significant reduction of mobility in cervical segments of patients with severe disc degeneration; in addition, it was more severely reduced in patients with severe cord compression than in those without it. In the cervical spine, it was found that although disc height, translational motion, and angular variation were significantly affected at the level of disc herniation, no significant changes were apparent in adjacent segments. kMRI also showed that lumbar degeneration is closely associated with disc degeneration, facet joint osteoarthritis and the pathological characteristics of the interspinous ligaments, ligamentum flavum and paraspinal muscles. RESULTS: Eleven articles (4162 patients) fulfilled the inclusion criteria and were reviewed. It was found that kMRI is more specific and sensitive than conventional MRI regarding relating patients' symptoms to objective findings on imaging that demonstrate pathology and biomechanics. In the kinetic position, kMRI improves detection of disc herniation by 5.78%-19.46% and thus provides a new means of studying the biomechanical mechanism(s) in degenerative spines. CONCLUSION: Kinetic MRI is effective for diagnosing, evaluating, and managing degenerative disease within the spine; however, it still has some limitations.


Assuntos
Vértebras Cervicais , Degeneração do Disco Intervertebral/diagnóstico , Vértebras Lombares , Imageamento por Ressonância Magnética , Fenômenos Biomecânicos , Vértebras Cervicais/fisiopatologia , Humanos , Degeneração do Disco Intervertebral/complicações , Degeneração do Disco Intervertebral/fisiopatologia , Vértebras Lombares/fisiopatologia , Imageamento por Ressonância Magnética/métodos , Amplitude de Movimento Articular , Compressão da Medula Espinal/etiologia
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