A Fiber-based Acl Model for Geometrical and Mechanical Simulations

ACL (Anterior Cruciate Ligament) has a fundamental role in knee biomechanics and ACL insuuciency is probably the most common knee pathology. Although widely investigated, ACL mathematical models are still controversial in simulations of knee kinematics. We have developed a new ACL model, made of 9 curvilinear independent bers, corresponding to the individual surface bers, which are described as a succession of 20 punctual physical particles linked by linear vis-coelastic relations, and they can twist, bend and stretch under applied forces. The model has been validated on 4 fresh pig knees and has given very consistent results to describe ACL anatomy, function and mechanics. Simulations of passive kinematics give coherent results on bers elongations, forces and ligament deformations, con-rming the expected correlation between bers' strain and stress. The advantage and the feature of this method with respect to previous models is the possibility to take into account more accurately ACL anatomy, mechanical properties and the ligament behaviour during range of motion. All input geometrical data, can be acquired in xed position, respect sizes and shapes of the ligament, envisaging a possible application on human ACL to develop surgical planning and simulation. Simulation du comportement mmcanique et ggommtrique de l'ACL basse sur une reprrsentation par bres RRsumm : Nous prrsentons un nouveau moddle de l'ACL (Anterior Cruciate Ligament) dans lequel on reprrsente le ACL par 9 bres inddpendants. Chaque bre est constituu de 20 masses ponctuelles liies entre elles par des connecteurs de force visco-lastiques. Cette reprrsentation permet de simuler le comportement de l'ACL en traction et en exion. Le moddle a tt testt sur 4 genoux frais de couchons, et il a donnn des rrsultat consistants avec l'anatomie de l'ACL, son fonctionnement et son mmcanique. La simulation du mouvement passive de l'ACL a donnn des rrsul-tats cohhrents concernant l''longation des bres, les forces, et les ddformation de ligament.