Loading...

A Practical Subject-specific FE Model of Human Knee Joint for Pre-planning of Tibial Osteotomy Surgery

Ali Aghajan, Majid | 2020

1353 Viewed
  1. Type of Document: M.Sc. Thesis
  2. Language: Farsi
  3. Document No: 53047 (08)
  4. University: Sharif University of Technology
  5. Department: Mechanical Engineering
  6. Advisor(s): Farahmand, Farzam
  7. Abstract:
  8. Knee joint simulation to analyze the process of osteotomy surgery has been studied in several researches and its effectiveness has been shown. However, these models include many components and details that impose significant time and cost on the patient due to the need for multiple data as well as extensive specialized activity to build and analyze the model. Thus, this study aims to provide a practical finite-element patient-specific model for predicting the outcome and planning of knee osteotomy surgery, such a way that it can be made and processed with little data and in a short time, and also requires little specialized activity. For this purpose, first, a detailed model of the knee joint was prepared, which was used as a reference model. The geometry and position of the components in this model were determined based on the MRI and CT-scan images. Then, by applying some changes to the components of the model, the sensitivity of the results to these changes was examined. The results showed that the model's behavior was not very sensitive to meniscus deformation, cartilage thickness, and slight changes in ligaments attachment position. Based on these results, four models were considered to simplify the behavior of soft tissues:Spring model, pad model, conceptual model and anatomical model.In these models, to characterize the design parameters (mechanical properties of alternative soft tissues) in the optimization process, the behavior of the virtual patient model (reference model) in CT-scan and standing-posture radiographic configurations were used as a criterion to determine these properties so that the simple models follow the behavior of the virtual joint. The cost function of the spring model at the optimization stage was calculated much higher than the acceptable values and had a significant error. Also, components of the pad model did not have enough movement freedom, so these two models were not considered as suitable models. The results of osteotomy surgery simulation using the optimized parameters for the conceptual model had a correlation coefficient of 0.45, which showed a slight similarity between the behavior of the conceptual model and the virtual joint. Eventually, the best results were obtained from the anatomical model, with a correlation coefficient of 83% in the osteotomy surgery simulation compared to the virtual patient model. Given that the anatomical model is able to simulate the behavior of the virtual joint with good accuracy, a process was proposed to reduce the cost of surgery simulation by reducing the need for imaging-data to provide geometry, and facilitating the modeling, meshing and analysis process. A program was also written to save time and reduce specialized activity by automating the characterization and simulation process
  9. Keywords:
  10. Osteotomy Surgery ; Finite Element Analysis ; Knee Modelling ; Varus-Valgus Deformity ; Patient-Specific Modeling ; Tibial Tubercle

 Digital Object List

 Bookmark

...see more