In vitro and in vivo kinematics of total knee arthroplasty—a review of the research at the Orthopaedic Bioengineering Laboratory of the Massachusetts General Hospital (MGH)

Quantitative data of total knee arthroplasty (TKA) kinematics is vital for understanding component failure and to provide guidelines for improvement of the component design. Our lab started studying TKA kinematics in 1998. First, we developed an in vitro robotic experimental setup to test knee kinematics after TKA surgery under various simulated physiological loading conditions. Second, we developed a dual fluoroscopic imaging system (DFIS) to analyze the in vivo knee kinematics after TKA surgery during functional activities. Using these in vitro and in vivo approaches, we have extensively investigated the kinematics of typical posterior cruciate retaining (CR) and posterior substituting (PS) TKAs. Analyses included six degrees-of-freedom (DOF) tibiofemoral joint kinematics, tibiofemoral articular contact locations, posterior cruciate ligament (PCL) function in CR TKAs and cam-post contact in PS TKAs. In addition we have studied the biomechanical factors that may affect flexion capabilities of the knee by comparing the biomechanics of conventional, high-flexion TKA designs with normal knees and knees with osteoarthritis (OA). In this review, we will briefly describe the in vitro and in vivo testing systems developed at our lab for TKA kinematics analyses followed by a summary of our research results on various TKA components.