Biomechanics of Total Disc Replacement for the Cervical Spine

颈椎全椎间盘置换术的生物力学

• 批准号: 8466778
• 负责人: Avinash G. Patwardhan
• 金额: --
• 依托单位: EDWARD HINES JR VA HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-04-01 至 2014-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8466778
• 关键词: 3-Dimensional; Activities of Daily Living; Adult; Affect; Age-Years; Aluminum; Analysis of Variance; Anterior; Area; Articular Range of Motion; Biological Preservation; Biomechanics; Caring; Categories; Cervical; Cervical spine; Characteristics; Clinical Research; Computer Simulation; Coupled; Coupling; Data; Degenerative Disorder; Disease; Excision; Facet joint structure; Female; Freedom; Height; Human; Implant; Individual; Joints; Lateral; Lead; Link; Literature; Longevity; Measurement; Measures; Mechanics; Medical; Mission; Modeling; Motion; Neurologic Dysfunctions; Operative Surgical Procedures; Outcome; Outcome Measure; Pain; Pathology; Patient Care; Pattern; Physiological; Population; Positioning Attribute; Posterior longitudinal ligament structure; Process; Prosthesis; Prosthesis Design; Radiculopathy; Relative (related person); Reporting; Research; Resected; Resistance; Risk; Rotation; Shapes; Specimen; Spinal Cord Diseases; Spinal Stenosis; Spondylosis; Stress; Surface; Symptoms; System; Techniques; Translating; Treatment outcome; Veterans; Width; Work; X-Ray Computed Tomography; abstracting; base; clinical practice; cost effective; data modeling; design; digital; experience; experimental analysis; falls; implantation; improved; in vivo; indexing; innovation; intervertebral disk degeneration; kinematics; male; prevent; relating to nervous system; research study; soft tissue; spine bone structure

DESCRIPTION (provided by applicant): Abstract Purpose: Activities of daily living require the sub-axial cervical spine (C2-C7) to have substantial mobility in flexion-extension, lateral bending and axial rotation. These segments also demonstrate a characteristic motion coupling between lateral bending and axial rotation. Cervical total disc replacement (TDR) has been clinically used to treat radiculopathy and myelopathy. The ability of the TDR to replicate physiologic motion is critical to protect adjacent levels from degeneration. Hypotheses: (H1) The ability of cervical TDR to restore physiologic primary and coupled motions and load distribution at the reconstructed segment would depend on the prosthesis design features. (H2) The ability of cervical TDR to restore physiologic quantity and quality of motions and load distribution at the reconstructed segment would depend on surgical techniques such as: (1) the width of the annular window made for implant insertion, (2) whether the PLL is preserved or resected, and (3) prosthesis position in the disc space. (H3) A second TDR at an adjacent level will not adversely affect the biomechanics of the index level TDR. Specific objectives: (1) Measure three-dimensional (3-D) intervertebral motion profiles and load sharing among the disc and facet joints in cervical spines under loads experienced during ADL for the following: (a) intact; (b) after C5-C6 TDR as a function of prosthesis design and surgical technique variability; and (c) after a second TDR at C6-C7. (2) Develop a new technique to generate specimen-specific, CT-based 3-D computer models to assess motions, gapping, and contact at the facet joints and uncovertebral joints in the intact segment and after TDR as a function of prosthesis design and variability in surgical implantation technique. Research Plan: This project will use a combination of experimental studies and CT-based specimen-specific modeling. Experimental Studies: The experiments will be performed using 60 fresh human cervical spine specimens of adult male and female donors <60 years of age. The specimens will be assigned to six prostheses groups (n=10 each) that fall into four design categories: (I) single spherical bearing design; (II) saddle-shaped bearing design; (III) mobile core design with two bearings; and (IV) six degrees-of-freedom compressible design. The surgical technique variables will include: (I) Implant position within the disc space (anterior vs. posterior); and (II) Integrity of the soft-tissue envelope at the implanted level including (a) the width of the window (narrow vs. wide) made in the anterior annulus for prosthesis insertion, and (b) the preservation or resection of posterior longitudinal ligament (intact vs. resected). CT-Based, Specimen-Specific Models: 3-D computer models of individual specimens (60 total) will be created from CT scans. Four aluminum markers implanted in each vertebra, visible on CT and included in the computer model, will be probed during the experiments to establish a 'digital link' between the specimen and its model. Experimental vertebral motion data will be used to 'drive' the computer model, producing validated measurements throughout the specimen's range of motion. The models will be used to assess facet joint and uncinate process articulations in terms of gap distances, relative localized motions, and contact areas. Statistical Analysis: Experimental data and model results will be analyzed using repeated-measures ANOVA with one factor (prosthesis design), and post hoc multiple comparisons. We estimate 10 specimens per prosthesis to give 80% statistical power in detecting a difference of at least 25% in the outcome measures. Significance: We propose to generate objective data on the abilities of cervical disc prostheses of different designs to restore physiologic cervical spine mechanics. In addition, we will develop an innovative technique to assess facet and uncovertebral joint motion in the intact segment and after implantation of disc prostheses using specimen-specific CT-based 3-D computer models. These findings can be immediately translated to clinical practice to improve the surgical treatment outcomes for painful degenerative disease of the cervical spine.

描述（由申请人提供）： 摘要目的：日常生活活动要求下颈椎（C2-C7）在屈伸、侧弯和轴向旋转方面具有相当大的活动性。这些节段还表现出侧向弯曲和轴向旋转之间的特征性运动耦合。颈椎全椎间盘置换术（TDR）已在临床上用于治疗神经根病和脊髓病。TDR复制生理运动的能力对于保护相邻节段免于退变至关重要。假设：（H1）颈椎TDR在重建节段恢复生理性初始和耦合运动以及载荷分布的能力取决于假体设计特征。(H2)颈椎TDR恢复重建节段运动和载荷分布的生理数量和质量的能力取决于手术技术，例如：（1）用于植入物插入的环形窗口的宽度，（2）PLL是保留还是切除，以及（3）假体在椎间隙中的位置。(H3)相邻节段的第二个TDR不会对索引节段TDR的生物力学产生不利影响。具体目标：（1）测量在ADL期间所经历的载荷下颈椎中的椎间盘和小关节之间的三维（3-D）椎间运动轮廓和载荷分配，用于以下：（a）完整;（B）在C5-C6 TDR之后，作为假体设计和手术技术可变性的函数;和（c）在C6-C7处的第二次TDR之后。(2)开发一种新技术，以生成骨特异性、基于CT的3-D计算机模型，以评估完整节段和TDR后小关节和钩椎关节的运动、间隙和接触，作为假体设计和手术植入技术可变性的函数。研究计划：该项目将使用实验研究和基于CT的特定于神经元的建模相结合。实验研究：实验将使用60个年龄<60岁的成年男性和女性供体的新鲜人颈椎标本进行。样本将被分配到六个假体组（每组n=10），分为四个设计类别：（I）单球面关节面设计;（II）鞍形关节面设计;（III）带有两个关节面的移动的核心设计;和（IV）六自由度可压缩设计。 手术技术变量将包括：（I）椎间隙内的植入物位置（前部与后部）;以及（II）植入节段软组织包膜的完整性，包括（a）在前环中制作的用于假体插入的窗口宽度（窄与宽），以及（B）后纵韧带的保留或切除（完整与切除）。基于CT的标本特定模型：将根据CT扫描创建单个标本（共60个）的三维计算机模型。在每个椎骨中植入四个铝标记，在CT上可见，并包括在计算机模型中，将在实验期间进行探测，以建立标本和其模型之间的“数字链接”。实验椎骨运动数据将用于“驱动”计算机模型，在整个标本的运动范围内产生经验证的测量值。这些模型将用于评估小关节和钩突关节的间隙距离、相对局部运动和接触面积。统计分析：将使用单因素（假体设计）重复测量ANOVA和事后多重比较分析实验数据和模型结果。我们估计每个假体10个样本，以提供80%的统计功效，检测结果测量中至少25%的差异。重要性：我们建议生成关于不同设计的颈椎间盘假体恢复生理颈椎力学能力的客观数据。此外，我们将开发一种创新的技术，以评估小关节和钩椎关节运动在完整的节段和植入椎间盘假体后，使用基于CT的三维计算机模型。这些发现可以立即转化为临床实践，以改善颈椎疼痛性退行性疾病的手术治疗效果。