An Early Development of Force Distribution Sensor Using Pressure-Sensitive Conductive Rubber for Soft Tissue Balance in Total Knee Arthroplasty

Total knee arthroplasty nowadays becomes a common procedure to restore the knee function for patients who suffered either natural knee diseases or injuries. The procedure effectively reduces pain and improves knee function with high rate of success. However, the risk of failure is still a problem despite this particular issue has been discussed for the past decades by researchers all over the world. The current implementation of the procedures relies heavily on the feel of the surgeons to ensure the right implantation of the prosthesis on the tibiofemoral component. A force distribution measurement system which has a sufficient accuracy for determining the location of tibiofemoral contact forces is being developed to address this concern. The system consisted of two pressure sensitive sensors, embedded in the trial insert for each condyle. The sensors were made up of pressure-conductive rubber with 8 x 16 of electrodes arrays at the front and backside of the rubber. The current study focuses on the reliability and validity of the measurement performed using the developed sensors. The results indicate good response of the rubber against constant applied force within the first two minutes before the measurement error start increasing over time.