Abstract
The applications and problems of biomechanical studies in the field of total knee arthroplasty (TKA) are summarized. There are three main kinds of biomechanical studies that relate to TKA: those using fresh-frozen cadaver knee specimens, clinical studies during and after TKA, and computational analyses such as three-dimensional finite element model (FEM) analysis and fluoroscopic analysis. Internationally, fresh-frozen cadaver knee specimens have been used in the design and development of TKA systems and for the improvement of operative techniques. However, for legal and cultural reasons, such specimens cannot be used in Japan. In clinical studies, kinematics can be assessed during TKA by means of navigation systems. Soft tissue balancers can also be used during TKA to assess the joint gap distance and angle before and after each procedure. The most important rule in clinical trials is not to adversely affect the patients. Three-dimensional FEM analysis can clearly reveal the equivalent stress on the post and condyles of the tibial insert. Fluoroscopic analysis is also useful to assess the kinematics of implanted knees. One problem with these studies is that the CAD data of each TKA system is necessary. TKA has been developed mainly in the United States of America and Europe. In Asia, deep knee flexion is one of the most important issues after TKA. TKA is not only a question of cutting and drilling bones, the operation also requires soft tissue balancing. Biomechanical studies can facilitate development of the best TKA designs and operative techniques for our patients.
