Evaluation of electromechanical impedance based structural health monitoring for detection of loosening in total knee arthroplasty

Abstract

Total Knee Arthroplasty (TKA) continues to be a common and important orthopedic procedure for many in the United States. Despite recent medical advancements and increasing knowledge in the orthopedic community, it has been determined that 20% of TKA patients are still dissatisfied with their knee replacements. Causes of this failure include septic loosening and wear on the bearing component of the implant. Another cause of failure that has received specific attention from the mechanical community is aseptic loosening, which has been attributed to unbalanced ligaments or misalignment of the implant components. Previous efforts have been made to detect loosening by using passive force sensors such as piezoelectric transducers or strain gauges to detect misalignment. An alternative to this is to perform active sensing or structural health monitoring to evaluate possible loosening before it becomes a critical concern to the patient. One method of structural health monitoring, called the electromechanical impedance (EMI) method, is particularly attractive as it can use a single, compact piezoelectric transducer to determine the state of the host structure. This work is intended to evaluate the ability of the EMI method in sensing loosening between the cement and bone of a TKA tibial tray. This work will utilize real tibial trays implanted into synthetic bone (Sawbone) to evaluate the feasibility of detecting loosening using the EMI method. The intention of this work is to serve as a foundation for further in-vivo and intraoperative studies.

Passive Biotelemetric Detection of Tibial Debonding in Wireless Battery-Free Smart Knee Implants

“…This is a significant improvement over our previous work, where we were not able to measure loosening at this distance. Other authors have proposed modified implants to detect loosening [ 33 , 35 , 40 , 41 , 42 , 43 ], most of which were also evaluated under simulated conditions. Of those concepts, an acoustic analysis technique was able to detect osseointegration in rabbits in vivo [ 44 ].…”

Simple Smart Implants: Simultaneous Monitoring of Loosening and Temperature in Orthopaedics With an Embedded Ultrasound Transducer

“…Smart implant concepts posited to detect loosening include analyses of vibrations using embedded accelerometers and transducers [9], [15]- [21] and of micromotions using embedded displacement sensors [10], [22], [23]. However, none have permeated into clinical practice which may be due to the significant modifications to implant architecture often required.…”