The Analysis Of Different Physical Parameter Prostheses On Femur Reconstruction In Femur-prosthesis System

With the rapid development of biomedical engineering, it brings the revolution of medical technique. However, the loss of hip joint function caused by pathologic change, accident and so on makes patients inconvenient seriously. Joint replacement, especially hip joint replacement is a successful surgical procedure, which can release and eliminate the pain of joint, advance life quality of patients and so on. Therefore, the domain of engineering and medicine pays much attention to studies on femur, especially hip joint. Hip joint replacement is significant for biomedical engineering. Because custom-built artificial femur prosthesis achieves the best match of the prosthesis with medullary cavity in total hip joint replacement, it can be more adaptable to biomechanics environment in body, get rid of femoral normal stress destruction, reduce stress shielding and prolong prosthesis longevity. However, due to the diversity of femoral geometric shape and the complexity of femoral structural material, the effective data on the influence of physical parameters on femoral reconstruction after the prosthesis is implanted in femoral medullary cavity are deficient up to the present.This subject is supported by the Research Fund for the Doctoral Program of Higher Education (No.20060611014). This research is to establish the model of digitized femur-prosthesis system and develop self-adapting program of bone reconstruction, then to analyze this model with finite element method in ANSYS software, lastly the effect of the prosthesis'structural shape, material property, physical dimension, contact form and other parameters on the stress-strain and bone reconstruction is compared and analyzed by computer simulation after the prosthesis is implanted in femoral medullary cavity. Thus the effect of the prosthesis design parameters'variety on bone reconstruction is evaluated before hip joint replacement. Mechanics foundation and accurate geometric parameters for the design of custom-built artificial femur prosthesis are provided.The main studies in this paper are described as following:①According to femoral CT images of the patient, outer and inner contour lines are picked up and enclosed disposal is done in CAD software. Using the method of merging and shearing the big surface, generating end surface and clearing up the small surface, the design of 3D solid model is optimized and the model is more similar to physiology characteristics. ②The prostheses of different parameters are designed by three different means. Virtual assembly of the femur-prosthesis system model is done in Pro/E software. Thus the foundation for the following analysis is done.③Based on the theory of bone reconstruction, the relation of femur- reconstruction self-adapting with mechanics excitation is studied under the function of natural physiological force after the hip joint prosthesis is implanted in femoral medullary cavity.④The bone reconstruction self-adapting program is developed by Visual C++ platform. The effect of physical parameters on bone reconstruction is quantitatively analyzed and the simulation is done in ANSYS software.⑤According to the applied stress of the femur-prosthesis system and the speed of femur reconstruction, different prostheses implanted in femoral medullary cavity, the effect on bone reconstruction is compared and analyzed.