Daily Activity of TKR Patients as Input for Wear Testing

描述（由申请人提供）：对于患有膝关节损伤和/或疾病的患者，全膝关节置换术（TKR）在缓解疼痛和改善功能方面越来越成功。尽管取得了成功，但由于磨损导致的膝关节植入失败仍然是一个突出的问题，通常导致翻修手术。模拟膝关节运动和负荷的模拟器被广泛用于评估和改进未来的膝关节假体设计。然而，目前用于模拟的输入数据是基于典型的正常受试者水平行走时的数据，尽管有证据表明超过75%的全膝关节假体患者行走异常。在这些活动中，日常活动水平、真实的膝关节负荷和膝关节运动特征，以及它们对TKR患者假体磨损的影响在很大程度上是未知的。为了为临床前磨损测试提供准确的输入数据，我们将测试TKR患者在日常身体活动中表现出与目前使用的膝关节模拟器不同的运动和负荷概况的假设。我们的初步数据表明，在瑞士TKR人口中，只有10%的日常活动用于“平地行走”。此外，这些患者的膝关节最常越过30度屈曲水平，而模拟器的膝关节最常越过10度屈曲水平。该数据强调了患者家庭和社区中膝关节功能使用与关节模拟器当前使用的输入数据之间的差异。我们将在使用Miller-Galante （MG）或Miller-Galante II型（MGII）假体的TKR受试者中验证我们的假设。受试者将佩戴一天的活动监测器，该监测器将提供他们全天的活动水平和膝关节活动范围的数据。受试者还将参与运动分析（点簇技术），这将提供更准确的测量膝关节在日常活动中的三维运动。基于在运动实验室中获得的运动学和动力学体内数据，我们将使用人工膝关节的数学模型计算接触力。

DESCRIPTION (provided by applicant): Total knee replacement (TKR) has shown increasing success in relieving pain and improving function for patients suffering from knee injury and/or disease. Despite this success, knee implant failure due to wear is still a prominent problem usually leading to revision surgery. Simulators mimicking the motions and loads of knee joints are widely used to evaluate and improve future designs of knee prostheses. However, the input data currently used for simulation is based on typical normal subjects during level walking although there is evidence that more than 75% of patients with a total knee prosthesis walk abnormally. Daily activity levels, realistic knee joint loads and knee motion profiles during these activities, as well as their impact on the wear of the prosthesis for TKR patients are largely unknown. In order to provide accurate input data for preclinical wear testing, we will test the hypothesis that patients with a TKR demonstrate a different motion and load profile during daily physical activities than what is currently used in knee joint simulators. Our preliminary data indicate that in a Swiss TKR population, only 10% of daily activities was spent on "level walking". In addition, the knee joint of these patients most often crossed the 30 degree flexion level, in contrast with the simulator, which crosses the 10 degree level most frequently. This data highlights the discrepancies found between the functional use of the knee joint in the patient's home and community and what is currently used as input data for joint simulators. We will test our hypothesis in TKR subjects who have a Miller-Galante (MG) or Miller-Galante type II (MGII) prosthesis. Subjects will wear an activity monitor for one day which will provide data on their activity level and knee range of motion throughout the day. Subjects will also participate in motion analysis (point cluster technique) which will provide more accurate measurements of the 3-D movement of the knee during these daily activities. Based on the kinematic and kinetic in vivo data derived in the motion laboratory, we will calculate contact forces using a mathematical model of the artificial knee.