Compartmental Force and Contact Location Sensing with Piezoelectric Transducers in Total Knee Arthroplasty
Total Knee Arthroplasty (TKA) has been a choice for the people who suffer from knee disease such as arthritis and knee injuries for more than three decades. One of the most important factors, which affects the outcomes of the TKA, is joint alignment during the surgery. Due to the importance of the alignment, numerous studies have been performed in order to establish a universal technique, which is adoptable for patients with different musculoskeletal structures. Although computer modeling, cadaver testing, and limited in vivo measurements have provided some useful information, establishment of a comprehensive model has not yet been achieved. The reason for the abovementioned issue is a lack of sufficient in vivo data obtained from the knee joint after the surgery. In this study, the application of embedded piezoelectric transducers in the bearing of a TKA is suggested in order to obviate the current limits. The piezoelectric elements can provide several functions including sensing, energy harvesting, and structural health monitoring. In particular, six piezoelectric sensors are placed on the bottom surface of the bearing and the sensing performance of the proposed device is investigated in this work. As a sensor, piezoelectric transducers are designed to measure the compartmental forces as well as the location of the contact points between the femoral and tibial components of the knee implant. The sensing performance of the system is studied via a combination of finite element analysis and experimental tests.