Wear Analysis of Intervertebral Total Disc Replacements

描述(由申请人提供)：椎间全盘置换(TOR)植入物可能预示着退行性间盘疾病治疗的范式转变。保留活动度可以避免邻近节段退行性变，这是一种公认的并发症渗出。根据欧洲令人鼓舞的经验和目前正在结束的IDE试验，FDA很可能在2005年初/年中批准两种领先的设计：Charite III和ProDisc。作为核聚变的替代品(在美国，每年大约有33万人)，这些设备的植入热潮似乎迫在眉睫。晚期磨损相关并发症的可能性令人担忧。这两种装置都使用金属对传统聚乙烯轴承，TDR患者比THR/TKR患者年轻10岁。此外，由于非常接近脊髓，植入失败的潜在后果比THR/TKR严重得多。科学界迅速面对TDR磨损问题至关重要。建议建立生物工程研究伙伴关系，为识别和处理TDR中与磨损有关的问题提供坚实的科学基础。目的1是开发临床前阶段TDR磨损评估技术。这将利用互补的数值和物理技术来完成：滑动距离耦合有限元分析(爱荷华)和伺服控制实验室模拟(利兹)。目的2是实现一种新的在体TDR放射学磨损测量方法，使用高分辨率数字图像分析来评估种植体金属终板的相对三维姿势位置。在记录了精确度后，姿势图像分析技术将用于测量正在进行的最大/最长的欧洲TDR系列之一(慕尼黑)的磨损。目的3是评价TDR磨屑(Leeds)的功能生物活性。在形态上逼真的模拟器产生的碎片将被用于在专门为反映局部脊柱环境而量身定做的培养准备中挑战细胞，从中将分析炎症/溶骨级联反应的关键指标。

DESCRIPTION (provided by applicant): Intervertebral total disc replacement (TOR) 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 effusion. Based on encouraging experience in Europe and now-concluding IDE trials, FDA approval is likely in early/mid 2005 for two leading designs: Charite III and ProDisc. As an alternative to fusion (approximately 330,000/year in the U.S.), an onrush of implantations of these devices seems imminent. The potential for late wear-related complications is concerning. Both devices 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 much more dire than for THR/TKR. It is crucial that the scientific community expeditiously confront the issue of TDR wear. A Bioengineering Research Partnership is proposed to provide a firm scientific basis for identifying and dealing with wear-related problems in TDR. Aim 1 is to develop techniques for TDR wear assessment in the pre-clinical phase. This will be done leveraging complementary numerical and physical techniques: sliding-distance-coupled finite element analysis (Iowa) and servo-controlled laboratory simulation (Leeds). Aim 2 is to implement a novel approach to in vivo TDR radiographic wear measurement (Iowa), using high-resolution digital image analysis to assess relative three-dimensional pose position of the implant's metallic end plates. After documenting accuracy/precision, the pose image analysis technique will be used to measure wear in one of the largest/longest-ongoing European TDR series (Munich). Aim 3 is to assess the functional biologic activity of TDR wear debris (Leeds). Morphologically realistic simulator-generated debris will be used to challenge cells in a culture preparation specifically tailored to reflect the local spinal environment, from which key metrics of the inflammatory/osteolytic cascade will be assayed.