| Contact mechanics and kinematics of artificial knee joint are very important for pre-clinical assessment of wear and movement performance of the prosthesis.However,the contact mechanics and kinematic properties of the artificial knee joint are closely related to the geometric parameters of the prosthesis.Therefore,the finite element model of artificial knee joint gait simulation was established,and the contact mechanics and kinematics performance of the model of artificial knee joints coronal plane with different geometric shapes and curved tibia insert prosthesis model with parameterized design were studied.In this paper,two different prosthesis models with different coronal plane geometric parameters were selected to perform standard gait simulation analysis to study their contact mechanics and kinemics performance.Meanwhile,parametric modeling method of tibia insert on the bearing surface of the artificial knee joint was introduced and the prosthesis models with different parameters were also established to study the influence of the geometric parameters of the bearing surface on the contact mechanics and kinematics of the artificial knee joint.In addition,detailed statement was conducted about the finite element modeling process of artificial knee joint gait simulation,including the displacement controlled element model of artificial knee joint under the standard gait and force control.The convergence of the model is validated initially for the asymmetric Zimmer NK-II prosthesis with linear coronal plane and the symmetric Depuy PFC prosthesis with curved coronal plane.The model converges only when the minimum element size reaches 0.0625 mm by fining the finite element mesh.In addition,edge effect appeared in the Zimmer NK-II prosthesis model,and the maximum contact stress increased significantly,which was about40% higher than that of the Depuy PFC prosthesis model without edge effect.The appearance of edge contact effect is closely related to the linear shape of the coronal plane design of Zimmer NK-II which provides an important basis for wear research and design guidance of artificial knee joint.In addition,the influence of the geometric parameters of the curved tibia insert on the contact mechanics and kinematics of the prosthesis was investigated.The results showed that the coronal plane curvature radius of tibia insert was closely related to the contact mechanical properties of the prosthesis,while the sagittal plane curvature radius of tibia insert was more closely related to the movement performance of the prosthesis,which provided important guidance for the design of artificial knee joint and the selection of prosthesis in clinical practice. |
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