Mechanics of the passive knee joint. Part 1: The role of the tibial articular surfaces in guiding the passive motion.
(2007)
Journal - Proceedings of the Institution of Mechanical Engineers. Part H, Journal of engineering in medicine (England )
Abstract :
The motion of the unloaded knee is associated with tibial internal rotation and femoral posterior translation. Although it is known that the passive motion is the result of the interaction between the articular surfaces and the ligaments, the mechanism through which the particular pattern of motion is guided is not completely understood. The goal of this study was to focus on the tibial geometry and to identify the roles that its geometric features have in guiding the passive knee motion. The method used in this study simplified the geometry of the tibial plateaux and the menisci into basic features that could be eliminated individually. The generated tibial geometry was implemented in a computer model to simulate the passive motion. Different parts of the geometry were eliminated individually and the comparison between the simulation results was used to identify the role that each part of the geometry had in guiding the passive motion. The medial meniscus was found as the feature that promoted the tibial internal rotation and restrained the femoral posterior translation. The lateral meniscus and the medial aspect of the tibial eminence, on the other hand, were found as the elements that confined the tibial internal rotation.
| ISSN : | 0954-4119 |
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| Mesh Heading : | Biomechanics Cartilage, Articular Computer Simulation Humans Knee Joint Movement Range of Motion, Articular Surface Properties Tibia anatomy & histology anatomy & histology anatomy & histology |
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| Mesh Heading Relevant : | Models, Biological methods physiology physiology physiology physiology physiology |
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Mechanics of the passive knee joint. Part 2: interaction between the ligaments and the articular surfaces in guiding the joint motion.
(2007)
Journal - Proceedings of the Institution of Mechanical Engineers. Part H, Journal of engineering in medicine (England )
Abstract :
The aim of this study was to examine how the interaction between ligament tensions and contact forces guides the knee joint through its specific pattern of passive motion. A computer model was built based on cadaver data. The passive motion and the ligament lengthening and force patterns predicted by the model were verified with data from the literature. The contribution of each ligament and contact force was measured in terms of the rotational moment that it produced about the tibial medial plateau and the anterior-posterior (AP) force that it exerted on the tibia. The high tension of the anterior cruciate ligament (ACL) and the geometric constraints of the anterior horns of the menisci were found to be key features that stabilized the knee at full extension. The mutual effect of the cruciates was found as the reason for the screw-home mechanism at early flexion. Past 300, the AP component of contact force on the convex geometry of the lateral tibial plateau and tension of the lateral collateral ligament (LCL) were identified as elements that control the joint motion. From 60 degrees to 90 degrees, reduction in the tension of the ACL was determined as a reason for continuation of the tibial anterior translation. From 90 degrees to 120 degrees, increase in the tension of the posterior cruciate ligament and the AP component of the contact force on the convex geometry of the lateral tibial plateau pushed the tibia more anteriorly. This anterior translation was limited by the constraining effects of the ACL tension and the AP component of the contact force on the medial meniscus. The important guiding role observed for the LCL suggests that it should not be overlooked in knee models.
| ISSN : | 0954-4119 |
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| Mesh Heading : | Biomechanics Cartilage, Articular Computer Simulation Friction Humans Knee Joint Ligaments, Articular Movement Range of Motion, Articular Surface Properties Tibia methods anatomy & histology anatomy & histology anatomy & histology |
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| Mesh Heading Relevant : | Models, Biological physiology physiology physiology physiology physiology physiology |
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