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: 7869914
• 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/7869914
• 关键词: 3-Dimensional; Activities of Daily Living; Adult; Affect; Age-Years; Aluminum; 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. PUBLIC HEALTH RELEVANCE: Relevance to VA The VA medical system is responsible for the care of a large number of veterans suffering from disabling symptoms associated with painful degenerative disease of the cervical spine, many of whom require surgery. Providing cost-effective care to these veterans represents a major concern in the VA patient care mission. This task is increasingly more demanding given that this is a growing segment of the veteran population. The appeal of disc replacement surgery is based on the premise that restoring physiologic motion to the reconstructed segment would alleviate the risk of adjacent segment disease that has been associated with fusion and prevent additional surgery. The findings of this study can be immediately translated to clinical practice to improve the surgical treatment outcomes for painful degenerative disease of the cervical spine. The results will also provide scientific implications for improvement of artificial cervical disc prosthesis design.

描述（由申请人提供）： 摘要目的：日常生活的活动需要轴下颈椎（C2-C7）在屈曲 - 伸展，侧向弯曲和轴向旋转方面具有很大的活动性。这些段还表明了侧向弯曲和轴向旋转之间的特征运动耦合。宫颈总椎间盘置换（TDR）已在临床上用于治疗根部性病和骨髓病。 TDR复制生理运动的能力对于保护相邻水平免受变性至关重要。假设：（H1）宫颈TDR恢复重建段的生理原发性和耦合运动以及负载分布的能力取决于假体设计特征。 （H2）宫颈TDR恢复重建段的运动量和运动质量和负载分布的能力取决于：（1）：（1）为植入物插入的环形窗口的宽度，（2）PLL是否保留还是（3）假体位置，以及（3）假体位置。 （H3）在相邻水平上的第二个TDR不会对索引水平TDR的生物力学产生不利影响。具体目标：（1）测量三维（3-D）椎间运动曲线和载荷分布和载荷共享在ADL期间经历的颈椎中的椎间盘和刻面关节之间的载荷分布：（a）完整； （b）在C5-C6 TDR之后，根据假体设计和外科技术变异性的函数； （c）在C6-C7处第二个TDR之后。 （2）开发一种新技术来生成基于CT的标本，基于CT的3-D计算机模型，以评估整个片段和TDR之后的小平台的运动，间隙和接触，并在TDR之后作为假体设计和手术植入技术的变异性的函数。研究计划：该项目将结合实验研究和基于CT的标本特异性建模。实验研究：将使用60个新鲜的成年男性和女性捐助者的新鲜人颈椎标本进行实验。样品将分配给六个假体组（n = 10），分为四个设计类别：（i）单球轴承设计； （ii）鞍形轴承设计； （iii）带有两个轴承的移动核心设计； （iv）六个自由度的可压缩设计。 手术技术变量将包括：（i）椎间盘空间内的植入位置（前与后部）； （ii）在植入水平上的软组织包络线的完整性，包括（a）窗户的宽度（狭窄vs.宽），在插入假体前环中制成，以及（b）后纵向韧带的保存或切除（完整的vs.切除）。基于CT的，特定于CT的样品模型：将通过CT扫描创建单个样品的3-D计算机模型（总计60个）。将在实验期间探测在CT上可见并包含在计算机模型中的每个椎骨中的四个铝标记，以在试样与其模型之间建立“数字链接”。实验性椎骨运动数据将用于“驱动”计算机模型，并在整个标本的运动范围内产生经过验证的测量。这些模型将用于评估方面的关节，并根据差距距离，相对局部运动和接触区域进行违反过程关节。统计分析：将使用具有一个因素（假体设计）的重复测量方差分析和事后多重比较来分析实验数据和模型结果。我们估计每个假体的10个标本在检测结果指标中至少25％的差异时具有80％的统计能力。意义：我们建议生成有关颈椎椎间盘假体能力的客观数据，以恢复生理性颈椎力学。此外，我们还将开发一种创新的技术，以评估完整段中的方面和透明关节运动，并在使用基于标本的基于CT的3-D计算机模型植入光盘假体后。这些发现可以立即转化为临床实践，以改善颈椎疼痛退行性疾病的手术治疗结果。 公共卫生相关性： 与VA相关的VA医疗系统负责照顾许多与颈椎疼痛退行性疾病有关的残疾症状的退伍军人，其中许多人需要手术。为这些退伍军人提供具有成本效益的护理是VA患者护理任务的主要关注点。鉴于这是退伍军人人口的越来越多的部分，这项任务越来越苛刻。椎间盘置换手术的吸引力是基于这样的前提：将生理运动恢复到重建的细分市场将减轻与融合有关的邻近细分疾病的风险，并防止其他手术。这项研究的发现可以立即转化为临床实践，以改善颈椎疼痛退行性疾病的手术治疗结果。结果还将为改善人工宫颈椎间盘假体设计提供科学意义。