*WINNER* Force and center of pressure detection in instrumented knee implant

Abstract

This won best graduate poster in Mechanical Engineering.

Growing demands for Total Knee Arthroplasty (TKA) and also total knee revision surgery combined with the cost, risk, and complication of the surgery have led to numerus attempts to improve surgical techniques, implant design, and postoperative orthopedic therapies. Although abundant information about knee function and reaction forces and moments has been provided by researchers through biomechanical models, cadaver testing, in-vitro testing, and limited in-vivo measurements, rigorous real-time in-vivo data from knee implants is still required to improve the performance of TKAs. Instrumented knee implants using piezoelectric (PZT) transducers have promising potential to satisfy clinical needs in terms of continuous in-vivo data acquisition, self-powered operation, and retention of prevalent implant design, which can ultimately lead to improved patient satisfaction. In this study, The design of an Ultra High Molecular Weight (UHMW) Polyethylene TKA bearing with four embedded PZT on the bottom surface is proposed and investigated to analyze the sensing ability of the design. As a result, this work includes two parts; the first part provides a Finite Element (FE) evaluation study on the performance of the design in terms of force behavior of the system as well as determination of Center of Pressure (CoP) on the contact surface of the bearing and femoral components of the TKR.  The second part involves an experimental test set up using the fabricated knee bearing with embedded piezoelectric transducers. The experimental results are compared to the FE results to investigate the correlation between the outcomes of the two studies.