Wear Analysis of Intervertebral Total Disc Replacements

项目概述/摘要椎间全椎间盘置换术（TDR）植入物可能预示着椎间盘退行性疾病治疗的范式转变。保持运动可以避免相邻节段退变，这是一种公认的融合并发症。基于欧洲令人鼓舞的经验和随后FDA在2004年和2005年的批准，Charity III和ProDisc TDR设备已被美国许多脊柱外科医生投入临床使用。作为核聚变的替代方案（在美国每年约30万），这类设备的广泛使用引起了人们的极大兴趣。然而，后期磨损相关并发症的可能性令人不安。Chariti和ProDisc都涉及金属非常规聚乙烯轴承，TDR患者比THR/TKR患者年轻10岁。此外，由于靠近脊髓，植入物失败的潜在后果比THR/TKR严重得多。至关重要的是，科学界必须迅速面对TDR磨损问题。由母体赠款支持的一个生物工程研究伙伴关系正在努力为查明和处理热带病防治中与磨损有关的问题提供坚实的科学基础。这项父母资助研究（通知号no - od -09-058，标题为NIH宣布竞争性修订申请恢复法案基金的可用性）涉及开发临床前阶段TDR磨损评估技术（目标1），实施体内TDR射线摄影磨损测量新技术（目标2），以及评估TDR磨损碎片的功能生物活性（目标3）。提出了对母基金的修订，以扩大和改进母基金具体目标1中研究的计算磨损模拟方面。拟议修订研究的目标是确定方法，通过该方法，可以从独立进行的销对板磨损试验中实际确定TDR计算磨损模拟中使用的实验来源的摩擦学磨损因素，以避免需要校准/链接到已经执行的TDR物理磨损模拟。这将为加速不同TDR设计的计算模拟以及测试与TDR磨损相关的新假设开辟道路，否则这些假设是不可能实现的。

DESCRIPTION (provided by applicant): Project Summary/Abstract Intervertebral total disc replacement (TDR) implants potentially herald a paradigm shift in the management of degenerative disc disease. Preservation of motion may avoid adjacent-segment degeneration, a well- recognized complication of fusion. Based on encouraging experience in Europe and subsequent FDA approvals in 2004 and 2005, the Charity III and ProDisc TDR devices have come into clinical use by many spine surgeons in the US. As an alternative to fusion (~300,000/year in the U.S.), there is substantial interest in increasingly wide usage of this class of devices. However, the potential for late wear-related complications is disconcerting. Both Chariti and ProDisc involve metal-on-conventional-polyethylene bearings, and the TDR patient population is a decade younger than for THR/TKR. Moreover, owing to close proximity of the spinal cord, the potential consequences of implant failure are substantially more dire than for THR/TKR. It is crucial that the scientific community expeditiously confront the issue of TDR wear. A Bioengineering Research Partnership supported by the parent grant is working to provide a firm scientific basis for identifying and dealing with wear-related problems in TDR. This parent grant research (Notice Number NOT-OD-09-058 titled NIH Announces the Availability of Recovery Act Funds for Competitive Revision Applications) involves developing techniques for TDR wear assessment in the pre-clinical phase (Aim 1), implementing a novel technique for in vivo TDR radiographic wear measurement (Aim 2), and assessing the functional biologic activity of TDR wear debris (Aim 3). A revision to the parent grant is proposed to expand and improve upon the computational wear simulation aspects under study in parent Specific Aim 1. The goal of the proposed revision research is to identify methodology by means of which the experimentally-sourced tribologic wear factors used in TDR computational wear simulations can be realistically determined from independently conducted pin-on- plate wear tests, to avoid the need for calibration/linkage to already-performed TDR physical wear simulations. This will open the way to expedited computational simulations of substantively different TDR designs, and to testing of novel hypotheses related to TDR wear, that otherwise would not be possible. PUBLIC HEALTH RELEVANCE: Project Narrative Relevance: Computer simulation of the wear of total disc replacement implants has great usefulness both for engineering design purposes and for surgical assessments. Revision research is proposed for ways to make these computer simulations more accurate and more versatile, by means of better accuracy of one of the key pieces of experimental information (known as the wear factor) needed as input information for these simulations.