Comparative Study of Micro Motion in Stem Implant and Legacy Stem Implant using FEA

Abstract

For the patients having trouble in performing day to today activities like walking, stair climbing, squatting etc., medical companies are providing various solutions like replacement of body’s natural joint with the artificial components. These artificial joints mimic the actual working of natural joint by providing real stability and actual range of motion by reconstructing the joint’s natural anatomy. One of the components is the stem implant which is inserted inside the Femur bone. This component bears the full body load and transfer it to the knee. This study is regarding the stability of the stem under load conditions. The displacement of the implant is studied with respect to the bone when it is fixed inside the bone during the surgery and when the patient performs stair climbing activity after the surgery. Here various types of implants are studied under the load and their behavior of micro-motion during the activity. FEA methodology is used to setup a method that can provide the results for it. The method is validated using the clinical data of legacy stem called Plasma. To confirm the population compatibility, another study is performed using SOMA (Stryker Orthopedic Modelling And Analysis) by analyzing canal taper angle and implant’s sitting position inside the bone. It was observed that there was less amount of micro-motion induced in the conical stem design when compared with legacy Plasma implant.