ANALYSIS OF THE TIBIO-FEMORAL CONTACT POINT IN TOTAL KNEE REPLACEMENT USING A MARKER BASED MOTION ANALYSIS SYSTEM

摘要

The tibio-femoral contact point in total knee replacements (TKR) is important for determining wear patterns and failure mechanisms of the polyethylene components. Furthermore, the contact point location is critical for determining muscle and ligament lever arms, leading to a more accurate prediction of the internal contact forces. In the past, the contact point has been derived from cadaver studies. However, this method does not provide a realistic physiologic contact point during different daily activities. Others have used dual orthogonal fluoroscopic imaging systems to measure the tibio-femoral contact location during movement [1-3]. While fluoroscopic imaging is compelling because it provides direct visualization of the articulating bodies, there are limitations. The present study proposes a non-invasive, in vivo method for tracking the tibio-femoral contact point during gait, using existing and available technology. The suggested process is based on subject-specific anatomy, the geometry of the prosthesis, and the six degrees-of-freedom motion between the tibia and the femur during stance phase. The purpose of the present study is to establish the methodologies to calculate the contact point, using two different techniques as a means of verification.