Department of Mechanical Engineering, Tennessee Technological University, Cookeville, TN 38505 USA.
Department of Orthopaedic Surgery, Indiana University School of Medicine, Indianapolis, IN, 46202, USA.
Med Eng Phys. 2020 Sep;83:64-72. doi: 10.1016/j.medengphy.2020.07.011. Epub 2020 Jul 21.
For the past three decades, total knee replacement has become the main solution for progressed knee injuries and diseases. Due to a lack of postoperative in vivo data, a universal correlation between intra- and postoperative soft tissue balance in the knee joint has not been established. In this work, an instrumented knee implant design with six piezoelectric transducers embedded in the tibial bearing is proposed. The aim of the presented device is to measure the total and compartmental forces as well as to track the location of contact points on the medial and lateral compartments of the bearing. A numerical analysis using finite element software is first performed to obtain the best sensory system arrangement inside the bearing. The chosen design is then used to fabricate a prototype of the device. Several experiments are designed and performed using the prototype, and the ability of the proposed system to track the location and magnitude of applied compartmental forces on the bearing is evaluated. The experimental results show that the instrumented knee bearing is able to accurately measure the compartmental force quantities with a maximum error of 2.6% of the peak axial load, and the contact point locations with a maximum error of less than 1 mm.
在过去的三十年中，全膝关节置换术已成为治疗进展性膝关节损伤和疾病的主要方法。由于缺乏术后体内数据，膝关节内、术后软组织平衡之间并没有建立普遍的相关性。在这项工作中，提出了一种带有六个嵌入在胫骨承窝中的压电传感器的器械化膝关节植入物设计。该设备的目的是测量总的和分室的力，并跟踪承窝的内侧和外侧分室上接触点的位置。首先使用有限元软件进行数值分析，以获得承窝内最佳的传感器系统布置。然后选择设计来制造设备的原型。使用原型设计并进行了多项实验，评估了所提出系统跟踪承窝上施加的分室力的位置和大小的能力。实验结果表明，仪器化膝关节承窝能够准确地测量分室力的数量，最大误差为峰值轴向负荷的 2.6%，接触点位置的最大误差小于 1 毫米。
