Dr. Coulongeat presented some more information regarding the behavior of the FlexPLI knee element compared to the human knee behavior using THUMS simulation (see document TF-BTA-7-08). He explained that the THUMS knee shows a different behavior due to the fact that the FlexPLI design does not completely follow the human body composition. He concluded that the FlexPLI may not be able to represent the human knee behavior, especially when rotation influences the kinematics of the knee. Mr. Schmitt had provided similar investigation results from his company (see document TF-BTA-7-07). These results show that the differences in the design of the THUMS model and the FlexPLI lead in general to – in several cases significantly – higher test results for the ACL and PCL elongation with the FlexPLI. This effect seems to be related to the FlexPLI design.

Dr. Konosu pointed out that, however, such comparison needs to be done with human knees but not with two different tools that may have used different validation procedures. Mr. Gehring wondered whether the results of those investigations can be understood as verification that there are no issues with the rotation of the FlexPLI for the other criteria to be assessed. Dr. Coulongeat responded that this had not been investigated.