caa a22 4500 605460604 CHVBK 20210128100239.0 cr unu---uuuuu 210128e20151101xx s 000 0 eng 10.1007/s00167-014-3167-2 doi (NATIONALLICENCE)springer-10.1007/s00167-014-3167-2 Post-cam mechanics and tibiofemoral kinematics: a dynamic in vitro analysis of eight posterior-stabilized total knee designs [Elektronische Daten] [N. Arnout, L. Vanlommel, J. Vanlommel, J. Luyckx, L. Labey, B. Innocenti, J. Victor, J. Bellemans] Purpose: Posterior cruciate ligament (PCL)-substituting total knee arthroplasty (TKA) designs were introduced to avoid paradoxical roll forward of the femur and to optimize knee kinematics. The aim of this in vitro study was to investigate post-cam function and contact mechanics and relate it to knee kinematics during squatting in eight contemporary posterior-stabilized TKA designs. Methods: All prostheses were fixed on custom-designed metal fixtures and mounted in a knee rig and five sequential-loaded squats were performed between 30° and 130° of flexion. Contact pressure and contact area were measured using pressure-sensitive Tekscan sensors on the posterior face of the post. Kinematics was recorded with reflective markers and infrared light-capturing cameras. Results: The post-cam mechanisms analyzed in this study are very variable in terms of design features. This leads to large variations in terms of the flexion angle at which the post and cam engage maximal contact force, contact pressure and contact area. We found that more functional post-cam mechanisms, which engage at lower flexion angle and have a similar behavior as normal PCL function, generally show more normal rollback and tibial rotation at the expense of higher contact forces and pressures. All designs show high contact forces. A positive correlation was found between contact force and initial contact angle. Conclusion: Post-cam contact mechanics and kinematics were documented in a standardized setting. Post-cam contact mechanics are correlated with post-cam function. Outcomes of this study can help to develop more functional designs in future. Nevertheless, a compromise will always be made between functional requirements and risk of failure. We assume that more normal knee kinematics leads to more patient satisfaction because of better mobility. Understanding of the post-cam mechanism, and knowing how this system really works, is maybe the clue in further development of new total knee designs. Springer-Verlag Berlin Heidelberg, 2014 In vitro study nationallicence Posterior-stabilized TKA nationallicence Post-cam failure nationallicence Kinematics nationallicence Arnout N. Orthopedie en Traumatologie, University Hospital Ghent, De Pintelaan 185, 9000, Ghent, Belgium aut Vanlommel L. University Hospitals Leuven, Weligerveld 1, 3012, Ghent, Belgium aut Vanlommel J. University Hospitals Leuven, Weligerveld 1, 3012, Ghent, Belgium aut Luyckx J. European Centre for Knee Research, Technologielaan, Heverlee, Belgium aut Labey L. European Centre for Knee Research, Technologielaan, Heverlee, Belgium aut Innocenti B. European Centre for Knee Research, Technologielaan, Heverlee, Belgium aut Victor J. Orthopedie en Traumatologie, University Hospital Ghent, De Pintelaan 185, 9000, Ghent, Belgium aut Bellemans J. University Hospitals Leuven, Weligerveld 1, 3012, Ghent, Belgium aut Knee Surgery, Sports Traumatology, Arthroscopy Springer Berlin Heidelberg 23/11(2015-11-01), 3343-3353 0942-2056 23:11<3343 2015 23 167 https://doi.org/10.1007/s00167-014-3167-2 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00167-014-3167-2 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Arnout N. Orthopedie en Traumatologie, University Hospital Ghent, De Pintelaan 185, 9000, Ghent, Belgium aut NATIONALLICENCE 700 1- Vanlommel L. University Hospitals Leuven, Weligerveld 1, 3012, Ghent, Belgium aut NATIONALLICENCE 700 1- Vanlommel J. University Hospitals Leuven, Weligerveld 1, 3012, Ghent, Belgium aut NATIONALLICENCE 700 1- Luyckx J. European Centre for Knee Research, Technologielaan, Heverlee, Belgium aut NATIONALLICENCE 700 1- Labey L. European Centre for Knee Research, Technologielaan, Heverlee, Belgium aut NATIONALLICENCE 700 1- Innocenti B. European Centre for Knee Research, Technologielaan, Heverlee, Belgium aut NATIONALLICENCE 700 1- Victor J. Orthopedie en Traumatologie, University Hospital Ghent, De Pintelaan 185, 9000, Ghent, Belgium aut NATIONALLICENCE 700 1- Bellemans J. University Hospitals Leuven, Weligerveld 1, 3012, Ghent, Belgium aut NATIONALLICENCE 773 0- Knee Surgery, Sports Traumatology, Arthroscopy Springer Berlin Heidelberg 23/11(2015-11-01), 3343-3353 0942-2056 23:11<3343 2015 23 167