Failure Mechanisms of Revision Joint Replacement

修正关节置换术的失效机制

• 批准号: 6333920
• 负责人: Joan E Bechtold
• 金额: $ 26.92万
• 依托单位: HENNEPIN HEALTHCARE RESEARCH INSTITUTE
• 依托单位国家: 美国
• 财政年份: 1996
• 资助国家: 美国
• 起止时间: 1996-08-01 至 2004-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6333920
• 关键词: biological models; biomaterial compatibility; biomaterial evaluation; biomaterial interface interaction; bone transplantation; dogs; growth factor; hydroxyapatites; implant; joint prosthesis; longitudinal animal study; mechanical stress; medical implant science; medical rehabilitation related tag; radiography; titanium

Our long term goal is to improve the success of revision joint replacements. In our original application we identified that a major deficit of revision implants is their diminished osteogenic performance. The objective for this proposal is to investigate autologous means for improving bony fixation in the revision implant. Specifically, we will study hypotheses addressing these three aims, (1) to improve access (of native growth factors, cells, marrow) to the implant interface by disrupting the sclerotic concentric bone (CB) barrier that forms during aseptic loosening, (2) to improve utilization and adhesion of native growth factors and cells via osteoconductive coatings encouraging bone growth directly on the implant surface, and (3) to augment the interface with local application of concentrated autologous growth factors. Aim 1: We will study improved access by determining if implant fixation parameters improve with a surgical procedure to disrupt the CB barrier. Aim 2: We will study hydroxyapatite (HA) and an immobilized RGD peptide surface (RGD) to determine if they improve utilization/adhesion as compared to titanium (Ti). Aim 3: We will study whether augmentation of the interface with autologous blood factors (concentrate of buffy coat in allograft carrier) improves interface fixation as compared to allograft alone, or to the ungrafted interface. We will use our experimental model of the primary and revision settings (established during the original proposal). This model uses the team's loaded micromotion device with over a decade of previous use (6.0mm diameter PMMA cylinder pistoning 500 microns for eight weeks with polyethylene particles, in 0.75mm gap) to engender a revision cavity with a bony and tissue response representative of an aseptically loosened human implant. At revision surgery, the PMMA implant is replaced with a prescribed implant/graft treatment (the primary site receives the same implant/graft treatment). Groupings are (a) stable, loaded Ti, HA and RGD implants, (b) with no graft, and allograft with or without growth factors, (c) in the primary setting, and the revision settings with and without disruption of the CB barrier. These 18 groups will be statistically compared with groups from the original proposal, to determine effectiveness, interactions and synergies of treatments. Outcome measures are histomorphometric (percent bone area and implant contact in zones, and connectivity) and mechanical (pushout strength, stiffness, energy, bone permeability). Also, the CB rim will be studied histomorphometrically and with an analytic mechanical model. The diverse set of unique competencies of our team, our established experimental model, and our long history of successful collaboration, bode well for our continuing investigations to improve the longevity of clinically vexing revision implants.

我们的长期目标是提高翻修关节置换术的成功率。在我们最初的应用中，我们发现修复植入物的主要缺陷是其成骨性能下降。本建议的目的是研究自体方法来改善翻修种植体的骨固定。具体来说，我们将研究以下三个目标的假设：(1)通过破坏无菌松动过程中形成的硬化同心骨（CB）屏障来改善（天然生长因子、细胞、骨髓）进入种植体界面的途径，(2)通过骨传导涂层直接促进种植体表面的骨生长来提高天然生长因子和细胞的利用和粘附性。(3)增强局部应用浓缩自体生长因子的界面。目的1：我们将通过确定植入物固定参数是否通过外科手术改善以破坏脑脊膜屏障来改善通路。目的2：我们将研究羟基磷灰石（HA）和固定化RGD肽表面（RGD），以确定与钛（Ti）相比，它们是否能提高利用率/粘附性。目的3：我们将研究与单独的同种异体移植物或未移植的移植物相比，是否用自体血液因子（同种异体移植物载体中的褐色被浓缩物）增强界面可以改善界面固定。我们将使用我们的初级和修订设置的实验模型（在原始提案期间建立）。该模型使用了该团队的加载微动装置，已有十多年的使用经验（6.0mm直径的PMMA圆柱体活塞500微米，与聚乙烯颗粒在0.75mm间隙内连续8周），以产生具有骨和组织反应的修复腔，代表无菌松动的人体植入物。在翻修手术中，用规定的种植体/移植物治疗替代PMMA种植体（原发部位接受相同的种植体/移植物治疗）。分组是(a)稳定的，负载Ti， HA和RGD植入物，(b)无移植物，移植或不移植生长因子的同种异体移植物，(c)初始设置，以及有和没有破坏CB屏障的修复设置。这18个组将与最初提议的组进行统计比较，以确定治疗的有效性、相互作用和协同作用。结果测量是组织形态学（骨面积百分比和种植体接触区域，连通性）和力学（推出强度，刚度，能量，骨渗透性）。此外，还将对CB边缘进行组织形态计量学和分析力学模型的研究。我们团队的各种独特能力，我们建立的实验模型，以及我们长期成功合作的历史，预示着我们将继续研究，以提高临床上令人烦恼的修复植入物的寿命。