Implant Research Center, School of Biomedical Engineering, Science & Health Systems, Drexel University, 3401 Market Street, Suite 345, Philadelphia, PA 19104, USA.
J Bone Joint Surg Am. 2013 Jun 5;95(11):e751-9. doi: 10.2106/JBJS.K.00522.
Wear, oxidation, and particularly rim impingement damage of ultra-high molecular weight polyethylene total disc replacement components have been observed following surgical revision. However, neither in vitro testing nor retrieval-based evidence has shown the effect(s) of impingement on the characteristics of polyethylene wear debris. Thus, we sought to determine (1) differences in polyethylene particle size, shape, number, or biological activity that correspond to mild or severe rim impingement and (2) in an analysis of all total disc replacements, regardless of impingement classification, whether there are correlations between the extent of regional damage and the characteristics of polyethylene wear debris.
The extent of dome and rim damage was characterized for eleven retrieved polyethylene cores obtained at revision surgery after an average duration of implantation of 9.7 years (range, 4.6 to 16.1 years). Polyethylene wear debris was isolated from periprosthetic tissues with use of nitric acid and was imaged with use of environmental scanning electron microscopy. Subsequently, particle size, shape, number, biological activity, and chronic inflammation scores were determined.
Grouping of particles by size ranges that represented high biological relevance (<0.1 to 1-μm particles), intermediate biological relevance (1 to 10-μm particles), and low biological relevance (>10-μm particles) revealed an increased volume fraction of particles in the <0.1 to 1-μm and 1 to 10-μm size ranges in the mild-impingement cohort as compared with the severe-impingement cohort. The increased volume fractions resulted in a higher specific biological activity per unit particle volume in the mild-impingement cohort than in the severe-impingement cohort. However, functional biological activity, which is normalized by particle volume (mm3/g of tissue), was significantly higher in the severe-impingement cohort. This increase was due to a larger volume of particles in all three size ranges. In both cohorts, the functional biological activity correlated with the chronic inflammatory response, and the extent of rim penetration positively correlated with increasing particle size, number, and functional biological activity.
The results of this study suggest that severe rim impingement increases the production of biologically relevant particles from motion-preserving lumbar total disc replacement components.
Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.
在接受手术翻修后，已观察到超高分子量聚乙烯全椎间盘置换部件的磨损、氧化，特别是边缘撞击损伤。然而，无论是体外测试还是基于检索的证据，都没有显示出撞击对聚乙烯磨损碎片特征的影响。因此，我们试图确定：(1)对应于轻微或严重边缘撞击的聚乙烯颗粒尺寸、形状、数量或生物活性的差异；以及(2)在对所有全椎间盘置换物的分析中，无论撞击分类如何，局部损伤的程度与聚乙烯磨损碎片的特征之间是否存在相关性。
在平均植入时间为 9.7 年（范围，4.6 至 16.1 年）后，对 11 个从手术翻修中获得的聚乙烯芯进行穹顶和边缘损伤程度的特征描述。使用硝酸从假体周围组织中分离聚乙烯磨损碎屑，并使用环境扫描电子显微镜进行成像。随后，确定颗粒的尺寸、形状、数量、生物活性和慢性炎症评分。
按大小范围对颗粒进行分组，这些范围代表高生物学相关性（<0.1 至 1-μm 颗粒）、中等生物学相关性（1 至 10-μm 颗粒）和低生物学相关性（>10-μm 颗粒），结果表明，与严重撞击组相比，在轻微撞击组中，<0.1 至 1-μm 和 1 至 10-μm 大小范围的颗粒体积分数增加。在轻微撞击组中，由于单位颗粒体积的比生物活性更高，因此增加的体积分数导致更高的特定生物活性。然而，功能生物活性（用组织体积（mm3/g）归一化）在严重撞击组中显著更高。这种增加是由于所有三个尺寸范围的颗粒体积更大所致。在两个队列中，功能生物活性均与慢性炎症反应相关，边缘穿透的程度与颗粒尺寸、数量和功能生物活性的增加呈正相关。
这项研究的结果表明，严重的边缘撞击会增加运动保留型腰椎全椎间盘置换部件产生的具有生物学相关性的颗粒。
预后 IV 级。有关证据水平的完整描述，请参见作者说明。
