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1.
Compr Psychiatry ; 105: 152220, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33348295

RESUMO

BACKGROUND: Family accommodation (FA) in obsessive-compulsive disorder (OCD) means that the relatives of patients are involved in, help or facilitate patients' ritual behaviors and avoidance, which is a frequent occurrence and underresearched phenomenon in China. Recent studies have suggested that FA is adversely associated with treatment response, contradictory to the goal of cognitive behavior therapy, a contributor to the maintenance of symptoms and increased symptom severity, and associated with low levels of family and social functioning. There is increasing interest and focus on establishing a family-based intervention for OCD treatment based on the inclusion of relatives by decreasing FA. The present study explored the psychometric properties of the Chinese version of the Family Accommodation Scale for OCD Interviewer-Rated (FAS-IR). METHOD: A total of 109 patients with OCD and 91 primary relatives were assessed in corresponding patient and family measures, and the FAS-IR was administered to relatives by trained interviewers. RESULTS: More than 90% of the relatives accommodated patients' symptoms with at least one kind of FA behavior over the previous week, and the incidence of extreme or everyday routines was as high as 59.3%. Exploratory factor analysis demonstrated two-factor structure for the whole scale, including (1) modification and facilitation, and (2) participation. Cronbach's alpha was 0.798 for the whole scale, and the interrater and test-retest reliability coefficients were 0.835 (95%CI: 0.603-0.937) and 0.882 (95%CI: 0.685-0.959), respectively. Convergent validity was supported in exploring FA and was associated with symptom severity, level of functional impairment and family functioning related to OCD. The FA was not significantly correlated with depressive symptoms rated by the patients, as evidence of acceptable divergent validity. There was no significant difference in FA total score based on patient gender, patient age, or relationship with patients. CONCLUSIONS: The Chinese version of the FAS-IR demonstrated excellent psychometric properties for assessing the degree of FA, suggesting that it is a useful and valuable instrument in clinical and research settings.


Assuntos
Transtorno Obsessivo-Compulsivo , China , Análise Fatorial , Família , Humanos , Transtorno Obsessivo-Compulsivo/diagnóstico , Psicometria , Reprodutibilidade dos Testes
2.
Sheng Wu Yi Xue Gong Cheng Xue Za Zhi ; 37(3): 527-532, 2020 Jun 25.
Artigo em Chinês | MEDLINE | ID: mdl-32597096

RESUMO

Total lumbar disc replacement is an alternative to interbody fusion for the effective treatment of symptomatic degenerative disc disease. This paper reviewed the history of ball-on-socket type artificial lumbar disc (ALD) prosthesis, which is a typical ALD prosthesis and summarized the ALD prosthesis research progress, according to different materials such as metal-on-metal, metal-on-polymer, and polymer-on-polymer prosthesis. The structural design factors of ball-on-socket type ALD prosthesis were analyzed and its prospect of development was also presented. The purpose of this paper is to provide a theoretical reference for the design of the ball-on-socket ALD prosthesis by reviewing the current state of ball-on-socket type ALD prosthesis.


Assuntos
Degeneração do Disco Intervertebral , Disco Intervertebral , Implantação de Prótese , Substituição Total de Disco , Simulação por Computador , Humanos , Degeneração do Disco Intervertebral/cirurgia , Vértebras Lombares , Resultado do Tratamento
3.
Sheng Wu Yi Xue Gong Cheng Xue Za Zhi ; 35(3): 493-500, 2018 06 25.
Artigo em Chinês | MEDLINE | ID: mdl-29938961

RESUMO

The mechanical properties of artificial intervertebral disc (AID) are related to long-term reliability of prosthesis. There are three testing methods involved in the mechanical performance evaluation of AID based on different tools: the testing method using mechanical simulator, in vitro specimen testing method and finite element analysis method. In this study, the testing standard, testing equipment and materials of AID were firstly introduced. Then, the present status of AID static mechanical properties test (static axial compression, static axial compression-shear), dynamic mechanical properties test (dynamic axial compression, dynamic axial compression-shear), creep and stress relaxation test, device pushout test, core pushout test, subsidence test, etc. were focused on. The experimental techniques using in vitro specimen testing method and testing results of available artificial discs were summarized. The experimental methods and research status of finite element analysis were also summarized. Finally, the research trends of AID mechanical performance evaluation were forecasted. The simulator, load, dynamic cycle, motion mode, specimen and test standard would be important research fields in the future.


Assuntos
Disco Intervertebral , Próteses e Implantes , Substituição Total de Disco , Fenômenos Biomecânicos , Análise de Elementos Finitos , Vértebras Lombares , Reprodutibilidade dos Testes , Pesquisa , Estresse Mecânico , Suporte de Carga
4.
Med Sci Monit ; 23: 3869-3877, 2017 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-28796755

RESUMO

BACKGROUND People with low back pain (LBP) alter their motion patterns during level walking and stair climbing due to pain or fear. However, the alternations of load sharing during the two activities are largely unknown. The objective of this study was to investigate the effect of LBP caused by lumbar disc herniation (LDH) on the muscle activities of 17 main trunk muscle groups and the intradiscal forces acting on the five lumbar discs. MATERIAL AND METHODS Twenty-six healthy adults and seven LDH patients were recruited to perform level walking and stair climbing in the Gait Analysis Laboratory. Eight optical markers were placed on the bony landmarks of the spinous process and pelvis, and the coordinates of these markers were captured during the two activities using motion capture system. The coordinates of the captured markers were applied to developed musculoskeletal model to calculate the kinetic variables. RESULTS LDH patients demonstrated higher muscle activities in most trunk muscle groups during both level walking and stair climbing. There were decreases in anteroposterior shear forces on the discs in the pathological region and increases in the compressive forces on all the lumbar discs during level walking. The symmetry of mediolateral shear forces was worse in LDH patients than healthy adults during stair climbing. CONCLUSIONS LDH patients exhibited different kinetic alternations during level walking and stair climbing. However, both adaptive strategies added extra burdens to the trunk system and further increased the risk for development of LDH.


Assuntos
Degeneração do Disco Intervertebral/fisiopatologia , Deslocamento do Disco Intervertebral/fisiopatologia , Dor Lombar/fisiopatologia , Sistema Musculoesquelético/fisiopatologia , Subida de Escada/fisiologia , Caminhada/fisiologia , Atividades Cotidianas , Adulto , Marcha/fisiologia , Humanos , Articulação do Joelho/fisiopatologia , Região Lombossacral , Masculino , Músculo Esquelético/fisiologia , Fenômenos Fisiológicos Musculoesqueléticos , Suporte de Carga/fisiologia
5.
BMC Musculoskelet Disord ; 18(1): 216, 2017 05 25.
Artigo em Inglês | MEDLINE | ID: mdl-28545560

RESUMO

BACKGROUND: Low back pain (LBP) is a common problem that can contribute to motor dysfunction. Previous studies reporting the changes in kinematic characteristics caused by LBP present conflicting results. This study aimed to apply the multisegmental spinal model to investigate the kinematic changes in patients with lumbar disc herniation (LDH) during five activities of daily living (ADLs). METHODS: Twenty-six healthy subjects and 7 LDH patients participated in this study and performed level walking, stair climbing, trunk flexion, and ipsilateral and contralateral pickups. The angular displacement of the thorax, upper lumbar (ULx), lower lumbar (LLx), pelvis, hip, and knee was calculated using a modified full-gait-model in the AnyBody modeling system. RESULTS: In the patient group, the ULx almost showed no sagittal angular displacement while the LLx remained part of the sagittal angular displacement during trunk flexion and the two pickups. In the two pickups, pelvic tilt and lower extremities' flexion increased to compensate for the deficiency in lumbar motion. LDH patients exhibited significantly less pelvic rotation during stair climbing and greater pelvic rotation in other ADLs, except in contralateral pickup. In addition, LDH patients demonstrated more antiphase movement in the transverse plane between ULx and LLx, during level walking and stair climbing, between thorax and pelvis in the two pickups. CONCLUSIONS: LDH patients mainly restrict the motion of LLx and ULx in the spinal region during the five ADLs. Pelvic rotation is an important method to compensate for the limited lumbar motion. Furthermore, pelvic tilt and lower extremities' flexion increased when ADLs were quite difficult for LDH patients.


Assuntos
Atividades Cotidianas , Deslocamento do Disco Intervertebral/fisiopatologia , Extremidade Inferior/fisiopatologia , Vértebras Lombares/fisiopatologia , Pelve/fisiopatologia , Amplitude de Movimento Articular/fisiologia , Adulto , Fenômenos Biomecânicos/fisiologia , Humanos , Deslocamento do Disco Intervertebral/complicações , Dor Lombar/etiologia , Dor Lombar/fisiopatologia , Masculino , Subida de Escada/fisiologia , Caminhada/fisiologia , Adulto Jovem
6.
Sheng Wu Yi Xue Gong Cheng Xue Za Zhi ; 34(1): 150-5, 2017 Feb.
Artigo em Chinês | MEDLINE | ID: mdl-29717604

RESUMO

Zero profile cervical interbody cage is an improvement of traditional fusion products and necessary supplement of emerging artificial intervertebral disc products. When applied in Anterior Cervical Decompression Fusion(ACDF), zero profile cervical interbody cage can preserve the advantages of traditional fusion and reduce the incidence of postoperative complications. Moreover, zero profile cervical interbody cage can be applied under the tabu symptoms of Artificial Cervical Disc Replacement(ACDR). This article summarizes zero profile interbody cage products that are commonly recognized and widely used in clinical practice in recent years, and reviews the progress of structure design and material research of zero profile cervical interbody cage products. Based on the latest clinical demands and research progress, this paper also discusses the future development directions of zero profile interbody cage.


Assuntos
Vértebras Cervicais , Vértebras Cervicais/cirurgia , Descompressão Cirúrgica , Humanos , Disco Intervertebral/cirurgia , Pescoço , Complicações Pós-Operatórias , Fusão Vertebral , Resultado do Tratamento
7.
Sheng Wu Yi Xue Gong Cheng Xue Za Zhi ; 33(1): 171-6, 2016 Feb.
Artigo em Chinês | MEDLINE | ID: mdl-27382760

RESUMO

This article reviews the progress of biomechanical studies on anterior cervical fusion and non-fusion surgery in recent years. The similarities and differences between animal and human cervical spines as well as the major three biomechanical test methods are introduced. Major progresses of biomechanical evaluation in anterior cervical fusion and non-fusion devices, hybrid surgery, coupled motion and biomechanical parameters, such as the instant center of rotation, are classified and summarized. Future development of loading method, multilevel hybrid surgery and coupling character are also discussed.


Assuntos
Vértebras Cervicais/cirurgia , Fusão Vertebral/métodos , Animais , Fenômenos Biomecânicos , Humanos , Rotação
8.
Sheng Wu Yi Xue Gong Cheng Xue Za Zhi ; 33(6): 1196-202, 2016 Dec.
Artigo em Chinês | MEDLINE | ID: mdl-29715419

RESUMO

Based on the application of finite element analysis in spine biomechanics,the research progress of finite element method applied in lumbar spine mechanics is reviewed and the prospect is forecasted.The related works,including lumbar ontology modeling,clinical application research,and occupational injury and protection,are summarized.The main research areas of finite element method are as follows:new accurate modeling process,the optimized simulation method,diversified clinical effect evaluation,and the clinical application of artificial lumbar disc.According to the recent research progress,the application prospects of finite element method,such as automation and individuation of modeling process,evaluation and analysis of new operation methods and simulation of mechanical damage and dynamic response,are discussed.The purpose of this paper is to provide the theoretical reference and practical guidance for the clinical lumbar problems by reviewing the application of finite element method in the field of the lumbar spine biomechanics.


Assuntos
Análise de Elementos Finitos , Vértebras Lombares/fisiologia , Modelos Biológicos , Fenômenos Biomecânicos , Simulação por Computador , Humanos , Estresse Mecânico
9.
Med Sci Monit ; 21: 3348-55, 2015 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-26529430

RESUMO

BACKGROUND: The ideal surgical approach for cervical disk disease remains controversial, especially for multilevel cervical disease. The purpose of this study was to investigate the biomechanics of the cervical spine after 3-level hybrid surgery compared with 3-level anterior cervical discectomy and fusion (ACDF). MATERIAL AND METHODS: Eighteen human cadaveric spines (C2-T1) were evaluated under displacement-input protocol. After intact testing, a simulated hybrid construct or fusion construct was created between C3 to C6 and tested in the following 3 conditions: 3-level disc plate disc (3DPD), 3-level plate disc plate (3PDP), and 3-level plate (3P). RESULTS: Compared to intact, almost 65~80% of motion was successfully restricted at C3-C6 fusion levels (p<0.05). 3DPD construct resulted in slight increase at the 3 instrumented levels (p>0.05). 3PDP construct resulted in significant decrease of ROM at C3-C6 levels less than 3P (p<0.05). Both 3DPD and 3PDP caused significant reduction of ROM at the arthrodesis level and produced motion increase at the arthroplasty level. For adjacent levels, 3P resulted in markedly increased contribution of both upper and lower adjacent levels (p<0.05). Significant motion increases lower than 3P were only noted at partly adjacent levels in some conditions for 3DPD and 3PDP (p<0.05). CONCLUSIONS: ACDF eliminated motion within the construct and greatly increased adjacent motion. Artificial cervical disc replacement normalized motion of its segment and adjacent segments. While hybrid conditions failed to restore normal motion within the construct, they significantly normalized motion in adjacent segments compared with the 3-level ACDF condition. The artificial disc in 3-level constructs has biomechanical advantages compared to fusion in normalizing motion.


Assuntos
Vértebras Cervicais/cirurgia , Fusão Vertebral/métodos , Substituição Total de Disco/métodos , Idoso , Fenômenos Biomecânicos , Placas Ósseas , Cadáver , Discotomia/métodos , Humanos , Degeneração do Disco Intervertebral/fisiopatologia , Degeneração do Disco Intervertebral/cirurgia , Deslocamento do Disco Intervertebral/fisiopatologia , Deslocamento do Disco Intervertebral/cirurgia , Pessoa de Meia-Idade , Amplitude de Movimento Articular , Estresse Mecânico , Técnicas do Sistema de Duplo-Híbrido
10.
Med Sci Monit ; 21: 4006-14, 2015 Dec 23.
Artigo em Inglês | MEDLINE | ID: mdl-26694835

RESUMO

BACKGROUND The ideal procedure for multilevel cervical degenerative disc diseases remains controversial. Recent studies on hybrid surgery combining anterior cervical discectomy and fusion (ACDF) and artificial cervical disc replacement (ACDR) for 2-level and 3-level constructs have been reported in the literature. The purpose of this study was to estimate the biomechanics of 3 kinds of 4-level hybrid constructs, which are more likely to be used clinically compared to 4-level arthrodesis. MATERIAL AND METHODS Eighteen human cadaveric spines (C2-T1) were evaluated in different testing conditions: intact, with 3 kinds of 4-level hybrid constructs (hybrid C3-4 ACDR+C4-6 ACDF+C6-7ACDR; hybrid C3-5ACDF+C5-6ACDR+C6-7ACDR; hybrid C3-4ACDR+C4-5ACDR+C5-7ACDF); and 4-level fusion. RESULTS Four-level fusion resulted in significant decrease in the C3-C7 ROM compared with the intact spine. The 3 different 4-level hybrid treatment groups caused only slight change at the instrumented levels compared to intact except for flexion. At the adjacent levels, 4-level fusion resulted in significant increase of contribution of both upper and lower adjacent levels. However, for the 3 hybrid constructs, significant changes of motion increase far lower than 4P at adjacent levels were only noted in partial loading conditions. No destabilizing effect or hypermobility were observed in any 4-level hybrid construct. CONCLUSIONS Four-level fusion significantly eliminated motion within the construct and increased motion at the adjacent segments. For all 3 different 4-level hybrid constructs, ACDR normalized motion of the index segment and adjacent segments with no significant hypermobility. Compared with the 4-level ACDF condition, the artificial discs in 4-level hybrid constructs had biomechanical advantages compared to fusion in normalizing adjacent level motion.


Assuntos
Fusão Vertebral/métodos , Adolescente , Adulto , Idoso , Fenômenos Biomecânicos , Vértebras Cervicais , Humanos , Técnicas In Vitro , Pessoa de Meia-Idade , Amplitude de Movimento Articular
11.
Sheng Wu Yi Xue Gong Cheng Xue Za Zhi ; 30(6): 1250-3, 2013 Dec.
Artigo em Chinês | MEDLINE | ID: mdl-24645606

RESUMO

Hepatic perfusion parameters play an important role in detecting and diagnosing diffusion diseases of liver. Based on a hemodynamic model. In this study, we described a fast and accurate method to calculate the perfusion parameters. First, we used a dual-input one-compartment kinetics model to illustrate the distribution of the contrast agent concentration among the body. Then, we used the Gaussian function to fit the scatter concentration data of portal vein and aorta, to obtain a liver agent concentration on function of time. Finally, we solved the model parameters by using Levenberg-Marquardt algorithm, and calculated the perfusion parameters. The results showed that the method proposed in this study could calculate the parameters precisely, and had a prosperous future application possibility.


Assuntos
Hemodinâmica , Fígado/fisiologia , Modelos Biológicos , Perfusão , Algoritmos , Meios de Contraste , Humanos
12.
Front Psychiatry ; 13: 970747, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36032239

RESUMO

Background: Family accommodation (FA) in obsessive compulsive disorder (OCD) is a common phenomenon. Based on the cost of training interviewers and the time required to administer the scale, the Family Accommodation Scale for Obsessive-Compulsive Disorder Interviewer-Rated (FAS-IR) has been restricted to specific settings. A self-rated version of the family accommodation scale may solve these problems. The aim of this study was to examine the reliability, validity and factor structure of the Family Accommodation Scale Self-rated version (FAS-SR), and the relationship among FA, symptom severity and functional impairment. Methods: In total, 171 patients with OCD and 145 paired relatives participated in this study. The Sheehan Disability Scale (SDS), Obsessive-Compulsive Inventory Revised (OCI-R), Zung Self-Rating Depression Scale (Zung-SDS), 12-item Family Assessment Devices (FAD-12), Clinical Global Impression of Severity Scale (CGI-S), Global Assessment of Functioning (GAF), and Yale-Brown Obsessive-Compulsive Scale (Y-BOCS) were used as tools for patients. The FAS-SR, FAS-IR, FAD-12, and the patients' symptom severity of Y-BOCS compulsion were used as tools for relatives. The psychometric properties of the FAS-SR were evaluated using Cronbach's alpha coefficient, test-retest reliability and validity. Mediation analysis was used to determine the relationship among FA, symptom severity and functional impairment. Results: A total of 97.9% of relatives of OCD patients reported at least one kind of FA behavior, and 56.6% of participants engaged in FA every day in the past week. The FAS-SR includes a three-factor structure: (1) providing reassurance and participation; (2) facilitation; and (3) modification. The scale's Cronbach's alpha and test-retest coefficients were 0.875 and 0.970, respectively. The total FAS-SR score was significantly positively associated with the Y-BOCS, FAD-12, CGI-S, FAS-IR, and SDS scores, and negatively associated with the total GAF score. FA partially mediated the relationship between symptom severity and functional impairment. Conclusion: The FAS-SR was proven to have satisfactory psychometric properties, and can play an important role in the evaluation and early intervention of OCD. This result indicates the importance of assessing symptom severity in conjunction with FA when evaluating OCD patients' functional impairment.

13.
Brain Sci ; 12(5)2022 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-35624982

RESUMO

Salivary Aß40, Aß42, t-tau, and p-tau 181 are commonly employed in Alzheimer's disease (AD) investigations. However, the collection method of these biomarkers can affect their levels. To assess the impact of saliva collection methods on biomarkers in this study, 15 healthy people were employed in the morning with six saliva collection methods. The chosen methods were then applied in 30 AD patients and 30 non-AD controls. The levels of salivary biomarkers were calculated by a specific enzyme-linked immunosorbent assay. The receiver operating characteristic was utilized to assess salivary biomarkers in AD patients. The results demonstrated that the highest levels of salivary Aß40, Aß42, t-tau, and p-tau were in different saliva collection methods. The correlations between different saliva biomarkers in the same collection method were different. Salivary Aß40, Aß42, t-tau, and p-tau had no significant association. Salivary Aß42 was higher in AD than in non-AD controls. However, p-tau/t-tau and Aß42/Aß40 had some relevance. The area under the curve for four biomarkers combined in AD diagnosis was 92.11%. An alternate saliva collection method (e.g., USS in Aß40, UPS in Aß42, t-tau, SSS in p-tau 181) was demonstrated in this study. Moreover, combining numerous biomarkers improves AD diagnosis.

14.
Materials (Basel) ; 15(8)2022 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-35454571

RESUMO

The proximal femur's numerical simulation could give an effective method for predicting the risk of femoral fracture. However, the majority of existing numerical simulations is static, which does not correctly capture the dynamic properties of bone fractures. On the basis of femoral fracture analysis, a dynamic simulation using incremental element deletion (IED)-based finite element analysis (FEA) was developed and compared to XFEM in this study. Mechanical tests were also used to assess it. Different impact speeds, fall postures, and cortical thicknesses were also studied for their implications on fracture types and mechanical responses. The time it took for the crack to shatter was shorter when the speed was higher, and the crack line slid down significantly. The fracture load fell by 27.37% when the angle was altered from 15° to 135°, indicating that falling forward was less likely to cause proximal femoral fracture than falling backward. Furthermore, the model with scant cortical bone was susceptible to fracture. This study established a theoretical foundation and mechanism for forecasting the risk of proximal femoral fracture in the elderly.

15.
Artigo em Inglês | MEDLINE | ID: mdl-35409805

RESUMO

BACKGROUND: Saliva has been studied as a better indicator of disorders and diseases than blood. Specifically, the salivary glucose level is considered to be an indicator of diabetes mellitus (DM). However, saliva collection methods can affect the salivary glucose level, thereby affecting the correlation between salivary glucose and blood glucose. Therefore, this study aims to identify an ideal saliva collection method and to use this method to determine the population and individual correlations between salivary glucose and blood glucose levels in DM patients and healthy controls. Finally, an analysis of the stability of the individual correlations is conducted. METHODS: This study included 40 age-matched DM patients and 40 healthy controls. In the fasting state, saliva was collected using six saliva collection methods, venous blood was collected simultaneously from each study participant, and both samples were analyzed at the same time using glucose oxidase peroxidase. A total of 20 DM patients and 20 healthy controls were arbitrarily selected from the above participants for one week of daily testing. The correlations between salivary glucose and blood glucose before and after breakfast were analyzed. Finally, 10 DM patients and 10 healthy controls were arbitrarily selected for one month of daily testing to analyze the stability of individual correlations. RESULTS: Salivary glucose levels were higher in DM patients than healthy controls for the six saliva collection methods. Compared with unstimulated saliva, stimulated saliva had decreased glucose level and increased salivary flow. In addition, unstimulated parotid salivary glucose was most correlated with blood glucose level (R2 = 0.9153), and the ROC curve area was 0.9316, which could accurately distinguish DM patients. Finally, it was found that the correlations between salivary glucose and blood glucose in different DM patients were quite different. The average correlation before breakfast was 0.83, and the average correlation after breakfast was 0.77. The coefficient of variation of the correlation coefficient before breakfast within 1 month was less than 5%. CONCLUSION: Unstimulated parotid salivary glucose level is the highest and is most correlated with blood glucose level, which can be accurately used to distinguish DM patients. Meanwhile, the correlation between salivary glucose and blood glucose was found to be relatively high and stable before breakfast. In general, the unstimulated parotid salivary glucose before breakfast presents an ideal saliva collecting method with which to replace blood-glucose use to detect DM, which provides a reference for the prediction of DM.


Assuntos
Glicemia , Diabetes Mellitus , Glucose/análise , Humanos , Oxirredutases , Glândula Parótida/química , Saliva/química
16.
J Mech Behav Biomed Mater ; 136: 105496, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36283297

RESUMO

Artificial nucleus pulposus (ANP) replacement as an alternative to the treatment of cervical spondylosis aims to relieve pain and restore the normal cervical motion. In this study, the PVA/PVP and PVA/Pectin composite hydrogels (CH)s with different concentrations were prepared by the freezing-thawing process, and their performances were tested. The effect of different concentrations on both kinds of PVA CHs were evaluated and analysed. The results demonstrated that both kinds of CHs had good swelling property (¿190%), compressive stress-strain characteristic response and stable performance, and they were not easy to degrade (¡9%). The elastic modulus of the PVA/PVP CH was close to that of nucleus pulposus prosthesis, and the weight loss ratio of the PVA/PVP CH was lower than that of PVA/Pectin CH under load condition. Further, the experimental results showed that the PVA/PVP CH with 15 wt% solute and 1 wt% PVP content had the best comprehensive performance, which may provide significant advantages for use in future clinical application in replacing nucleus pulposus.


Assuntos
Hidrogéis , Núcleo Pulposo , Álcool de Polivinil , Módulo de Elasticidade , Pectinas
17.
Orthop Surg ; 14(9): 2339-2349, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35946442

RESUMO

OBJECTIVE: To investigate the biomechanics of transforaminal lumbar interbody fusion (TLIF) with interspinous process device (IPD) or pedicle screw fixation under both static and vibration conditions by the finite element (FE) method. METHOD: A validated FE model of the L1-5 lumbar spine was used in this study. This FE model derived from computed tomography images of a healthy female adult volunteer of appropriate age. Then the model was modified to simulate L3-4 TLIF. Four conditions were compared: (i) intact; (ii) TLIF combined with bilateral pedicle screw fixation (BPSF); (iii) TLIF combined with U-shaped IPD Coflex-F (CF); and (iv) TLIF combined with unilateral pedicle screw fixation (UPSF). The intact and surgical FE models were analyzed under static and vibration loading conditions respectively. For static loading conditions, four motion modes (flexion, extension, lateral bending, and axial rotation) were simulated. For vibration loading conditions, the dynamic responses of lumbar spine under sinusoidal vertical load were simulated. RESULT: Under static loading conditions, compared with intact case, BPSF decreased range of motion (ROM) by 92%, 95%, 89% and 92% in flexion, extension, lateral bending and axial rotation, respectively. While CF decreased ROM by 87%, 90%, 69% and 80%, and UPSF decreased ROM by 84%, 89%, 66% and 82%, respectively. Compared with CF, UPSF increased the endplate stress by 5%-8% in flexion, 7%-10% in extension, 2%-4% in lateral bending, and decreased the endplate stress by 16%-19% in axial rotation. Compared with CF, UPSF increased the cage stress by 9% in flexion, 10% in extension, and decreased the cage stress by 3% in lateral bending, and 13% in axial rotation. BPSF decreased the stress responses of endplates and cage compared with CF and UPSF. Compared BPSF, CF decreased the facet joint force (FJF) by 6%-13%, and UPSF decreased the FJF by 4%-12%. During vibration loading conditions, compared with BPSF, CF reduced maximum values of the FJF by 16%-32%, and vibration amplitudes by 22%-35%, while UPSF reduced maximum values by 20%-40%, and vibration amplitudes by 31%-45%. CONCLUSION: Compared with other surgical models, BPSF increased the stability of lumbar spine, and also showed advantages in cage stress and endplate stress. CF showed advantages in IDP and FJF especially during vertical vibration, which may lead to lower risk of adjacent segment degeneration. CF may be an effective alternative to pedicle screw fixation in TLIF procedures.


Assuntos
Parafusos Pediculares , Fusão Vertebral , Adulto , Feminino , Humanos , Fenômenos Biomecânicos/fisiologia , Análise de Elementos Finitos , Vértebras Lombares/fisiologia , Vértebras Lombares/cirurgia , Amplitude de Movimento Articular , Fusão Vertebral/métodos , Vibração
18.
Clin Biomech (Bristol, Avon) ; 98: 105738, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35987169

RESUMO

BACKGROUND: Recently, more and more people suffer from low back pain triggered by lumbar degenerative disc disease. The mechanical factor is one of the most significant causes of disc degeneration. This study aims to explore the biomechanical responses of the intervertebral disc, and investigate the process of disc injury by the theory of continuum damage mechanics. METHODS: A finite element model of the L4-L5 lumbar spine was developed and validated. The model not only considered changes in permeability coefficient with strain, but also included physiological factors such as osmotic pressure. Three loading conditions were simulated: (A) static loads, (B) vibration loads, (C) injury process. FINDINGS: The simulation results revealed that the facet joints shared massive stresses of the intervertebral discs, and prevented excessive lumbar spine movement. However, their asymmetrical position may have led to degeneration. The von Mises stress and pore pressure of annulus fibrosus showed significantly different trends under static loads and vibration loads. The von Mises stress of nucleus pulposus was not sensitive to vibration loads, but its pore pressure was conspicuously influenced by vibration loads. The injury first appeared at the posterior centre, and then, it gradually expanded along the edge of the intervertebral disc. With an increase in the loading steps, the damage rate of the intervertebral disc increased logarithmically. INTERPRETATION: The variation in the biomechanical performance of the intervertebral disc could be attributed to the periodic movement of internal fluids. This study might be helpful for understanding the mechanism of intervertebral disc degeneration.


Assuntos
Degeneração do Disco Intervertebral , Deslocamento do Disco Intervertebral , Disco Intervertebral , Fenômenos Biomecânicos , Análise de Elementos Finitos , Humanos , Disco Intervertebral/fisiologia , Vértebras Lombares/fisiologia , Estresse Mecânico
19.
Artigo em Inglês | MEDLINE | ID: mdl-36141981

RESUMO

Spinal maladies are among the most common causes of pain and disability worldwide. Imaging represents an important diagnostic procedure in spinal care. Imaging investigations can provide information and insights that are not visible through ordinary visual inspection. Multiscale in vivo interrogation has the potential to improve the assessment and monitoring of pathologies thanks to the convergence of imaging, artificial intelligence (AI), and radiomic techniques. AI is revolutionizing computer vision, autonomous driving, natural language processing, and speech recognition. These revolutionary technologies are already impacting radiology, diagnostics, and other fields, where automated solutions can increase precision and reproducibility. In the first section of this narrative review, we provide a brief explanation of the many approaches currently being developed, with a particular emphasis on those employed in spinal imaging studies. The previously documented uses of AI for challenges involving spinal imaging, including imaging appropriateness and protocoling, image acquisition and reconstruction, image presentation, image interpretation, and quantitative image analysis, are then detailed. Finally, the future applications of AI to imaging of the spine are discussed. AI has the potential to significantly affect every step in spinal imaging. AI can make images of the spine more useful to patients and doctors by improving image quality, imaging efficiency, and diagnostic accuracy.


Assuntos
Inteligência Artificial , Radiologia , Previsões , Humanos , Aprendizado de Máquina , Reprodutibilidade dos Testes
20.
Clin Biomech (Bristol, Avon) ; 84: 105339, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33780788

RESUMO

BACKGROUND: Anterior lumbar interbody fusion combined with supplementary fixation has been widely used to treat lumbar diseases. However, few studies have investigated the influence of fixation options on facet joint force and cage subsidence. The aim of this study was to explore the biomechanical performance of anterior lumbar interbody fusion with various fixation options under both static and vertical vibration loading conditions. METHODS: A previously validated finite element model of the intact L1-5 lumbar spine was employed to compare five conditions: (1) Intact; (2) Fusion alone; (3) Fusion combined with anterior lumbar plate; (4) Fusion combined with Coflex-F fixation; (5) Fusion combined with bilateral pedicle screw fixation. The models were analyzed under static and vertical vibration loading conditions respectively. FINDINGS: Bilateral pedicle screws provided highest stability at surgical level. Applying supplementary fixation diminished the dynamic responses of lumbar spine. Compared with anterior lumbar plate and Coflex-F device, bilateral pedicle screws decreased the stress responses of the endplates and cage under both static and vibration conditions, while increased the facet joint force at adjacent levels. As for comparison between Coflex-F device and anterior lumbar plate, results showed a similarity in biomechanical performance under static loading, and a slightly higher dynamic response of the latter under vertical vibration. INTERPRETATION: The biomechanical performance of lumbar spine was significantly influenced by the variation of fixations under both static and vibration conditions. Bilateral pedicle screws showed advantages in stabilizing surgical segment and relieving cage subsidence, but may increase the facet joint force at adjacent levels.


Assuntos
Parafusos Pediculares , Fusão Vertebral , Fenômenos Biomecânicos , Análise de Elementos Finitos , Humanos , Vértebras Lombares/cirurgia , Amplitude de Movimento Articular , Vibração
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