| Summary: | 碩士 === 國立臺灣大學 === 醫學工程學研究所 === 92 === Total knee arthroplasty (TKA) has been the main choice of treatment for advanced degenerative knee osteoarthritis over the last few decades with excellent long-term survivorship. However, there is still searching for improvement, such as crack propagation, functional range of motion, etc., as well as potential problems that may emerge in the future. Injury or removal of any of the force-bearing structures will inevitably affect the function of the knee, and whether to preserve the posterior cruciate ligament (PCL) remains controversial. Therefore, posterior stabilized (PS) and posterior cruciate retaining (CR) type of TKRs are both available. Previous studies had used several approaching methods to estimate TKRs biomechanic behaviors, but they did not consider kinematics and kinetics which would affect the crack path of ultra-high molecular polyethylene (UHMWPE). Therefore the main purpose of this study was to investigate the relationship of the kinematics, ligamentary force, stress of UHMWPE, and crack propagation patterns between the two types of TKR’s design during functional activities with ligament attached three-dimensional finite element analysis (FEA). The kinematic data during upstairs was obtained from video-fluoroscopy method in vivo. The stability test (anterior-posterior draw test etc.) was performed to validate the accuracy of the model and contact behavior and subsurface crack path of the two types during upstairs were implemented.
The stability test results showed that PS type has higher resistances in anterior-posterior displacement and internal-external rotation. It was influenced by the design of cam-spine to resist the external force and moment. The subsurface crack propagation analysis showed the thin and round shaped crack pattern. With the completed FE model including ligaments and accurate relative kinematic data, the present study showed more reliable and accurate results.
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