Etiology and Prevention of Loss of Fixation in Cemented Knee Replacements

描述(由申请人提供)：全膝关节置换术是美国最常见的全关节手术，在过去的20年里，手术的数量急剧增加，每年超过58万例。尽管骨水泥全膝关节置换术总体上取得了成功，但需要翻修手术的无菌性松动仍然很常见，特别是对于更年轻和更活跃的患者。从骨水泥胫骨托盘组件中获得的新的体内试验数据显示，与胫骨托盘下的骨水泥相连的小梁骨有广泛的吸收，这种吸收可能发生在植入后的最初几年内。工作假说是，植入后骨水泥和骨之间的机械微互锁早期丢失，这导致胫骨托盘组件的功能强度丧失。在临床实践中，Interlck的丢失可能导致组件迁移和无菌性松动的风险增加，特别是对高要求的患者。这项研究计划的目标是实现在患者一生中都能成功发挥作用的关节置换术，而不需要翻修。在这次竞争性更新中，申请者利用从当前融资周期中获得的经验，在活体服务后固定全髋关节置换，并将这些经验与评估和解决与膝关节置换相关的松动问题的新方法结合起来。其具体目的是(1)发现体内服务后固定形态的时间和空间变化，特别是关注短期的体内服务；(2)确定这些形态变化对固定界面和完整的胫骨托盘结构/力学功能关系的影响；(3)探索交错的骨水泥-骨区导致骨小梁吸收的潜在力学机制；(4)确定体内服务导致整体构建物功能强度的损失；和(5)进行平移生物力学研究，以通过使用有针对性的设计改变来改善向胫骨托盘下侧的负荷转移(称为A型方案)来减少骨丢失。如果托盘下的骨小梁丢失无法防止(称为B型情况)，则确定‘正常’和‘高要求’患者为防止松动所需的远端固定量。实验和计算方法的协同结合被用来解决这些目标。 公共卫生相关性：在全膝关节置换中，植入物与骨之间的固定丢失仍然是导致早期松动的最常见原因，这导致额外的手术和松动部件的更换。这项工作调查了在手术时放置关节置换术后，与骨水泥相连以进行固定的骨骼是如何变化的。该项目的目标是通过改变植入物的设计和手术技术，找到防止固定物丢失的新方法。

DESCRIPTION (provided by applicant): Total knee replacement is the most common total joint procedure in the United States, and the number of procedures has grown dramatically over the past two decades to over the 580,000 per year. Despite the general success of cemented total knee replacement, aseptic loosening requiring a revision surgery is still common, particularly for younger and more active patients. New pilot data obtained from cemented tibial tray components following in vivo service show that there is extensive resorption of trabecular bone that interlocks with cement under the tibial tray and that this resorption may occur within the first few years following implantation. The working hypothesis is there is an early loss of mechanical micro-interlock between the cement and bone following implantation and this results in a loss of functional strength of the tibial tray component. In clinical practice, loss of interlck could cause an increased risk of component migration and aseptic loosening, particularly for high demand patients. The goal of this research program is to achieve arthroplasties that function successfully for the lifetime of the patient without the need for revision. In this competitive renewal the applicants leverage the experience gained from the current funding cycle on fixation of total hip replacement following in vivo service and combine these with new approaches to assess and address loosening issues associated with knee replacements. The specific aims are to (1) discover the temporal and spatial changes to the fixation morphology following in vivo service with particular attention to short term in vivo service; (2) determine th influence of these morphological changes on the structure/mechanical function relationship for the fixation interfaces and complete tibial tray constructs; (3) explore potential mechanical mechanisms responsible for trabecular bone resorption from interdigitated cement-bone regions; (4) determine the loss of functional strength of whole constructs due to in vivo service; and (5) perform translational biomechanics studies to mitigate bone loss through improved load transfer to the underside of the tibial tray (termed a type A scenario) using targeted design changes. If trabecular bone loss under tray cannot be prevented (termed a type B scenario), determine amount of distal fixation needed to prevent loosening for 'normal' and 'high demand' patients. A synergistic combination of experimental and computational methods is used to address these aims. PUBLIC HEALTH RELEVANCE: Loss of fixation between implant and bone in total knee replacement remains the most common cause of early loosening which leads to an additional surgery and replacement of the loose component. This work investigates how the bone that interlocks with the cement for fixation changes after placement of the joint replacement at time of surgery. The goal of this project is to find new approaches to prevent loss of fixation through changes in implant design and surgical technique.