Visualisation of tibiofemoral contact in total knee replacement using optical device.

An in situ optical visualization technique (OVT) has been developed to identify the tibiofemoral contact (TFC) area during prosthesis indentation. An artificial total knee replacement (TKR) with borosilicate glass femoral component has been reproduced similarly to the original one. The medial and lateral contact areas have been observed, located and measured by means of in situ OVT. Therefore, it was experimentally possible to ensure a good axial alignment of the femoral component and tibial polyethylene insert. In addition, experimental measurement for load-displacement curves became reproducible. Furthermore, the evolution of the medial and lateral TFC areas as a function of the normal load was established. Finally, this study has shown that the in situ OVT is a simple in vitro method that provides comparable results with well-known methods such as Fuji film technique.