Papers by Author: Ye Yeon Won

Abstract: To analyze the importance of bone quality, we studied 21 primary compressive trabecular system by micro-computed tomography(micro-CT), finite element analysis and destructive mechanical test. Significant correlations were found between histomorphometry and biomechanical parameters. The results indicate that the bone quality of primary compressive trabecular system is determined more by its combined micro-structural parameters (histomorphometry) and biomechanical parameters than histomorphometry only. Assessment of trabecular bone by finite element analysis may become important not only for assessment of bone quality but also for prediction of bone fracture risk of bone degeneration.

Abstract: Considerable researchers analyzed the effects of hormone treatment on osteoporotic vertebral bones. Hormone treatment of age-related osteoporotic bone has a potential to decrease an incidence of osteoporosis. In the present paper, experimental and simulated tests for the mechanical characteristics of osteoporotic models and their hormone-treated models were investigated. Three dimensional (3D) geometries of the models (rapid prototyped and finite element models) were generated from high resolution micro-computed tomography ($-CT, Skyscan 1076, Skyscan, Belgium) scan data for the central parts of the second lumbar vertebrae. From these 3D geometries, cubic specimens with side length 6.5mm were formed and analyzed. Rapid prototyped (RP) models, instead of the real bone specimen, of vertebral trabecular bones were created in the fused deposition modeling (FDM) machine. In the present study, experimental compressions test for RP models were carried out by the INSTRON testing machine (8874 series, Instron, UK). The mechanical characteristics of finite element (FE) models for simulated compression tests were compared with physical predictions from RP models for experimental compression test. As a result, it is found that the hormone therapy is likely to be less effective than reported by previous researchers. A remarkable agreement was achieved between the results obtained from the experimental tests for RP models and simulated tests for FE models.

Abstract: This study investigates micro-structural and mechanical properties of trabecular bone in human femoral head with and without osteoporosis using a micro-CT and a finite element model. 15 cored trabecular bone specimens with 20
of diameter were obtained from femoral heads with osteoporosis resected for total hip arthroplasty, and 5 specimens were removed from femoral head of cadavers, which has no history of musculoskeletal diseases. A high-resolution micro-CT system was used to scan each specimen to obtain histomorphometry indexes. Based on the micro-images, a FE-model was created to determine mechanical property indexes. While the non-osteoporosis group had increases the trabecular thickness, the bone volume, the bone volume fraction, the degree of anisotropy and the trabecular number compared with those of osteoporotic group, the non-osteoporotic group showed decreases in trabecular separation and structure model index. Regarding the mechanical property indexes, the reaction force and the Young's modulus were lower in the osteoporotic group than in non-osteoporotic group. Our data shows salient deteriorations in trabecular micro-structural and mechanical properties in human femoral head with osteoporosis.

Abstract: Investigation of the bone mineral density (BMD), microstructural and mechanical properties in the Otsuka Long Evans Tokushima Fatty (OLETF) and Otsuka Long Evans Tokushima Fatty (LETO) rats were performed. The BMD and microstructural analyses were carried out using PIXI-mus and non-invasive highresolution micro-computed tomography (micro-CT) system. The mechanical properties analyses were determined by finite element analysis based on micro-images. The BMD was significantly larger in LETO rat than in OLETF rat. The microstructural and mechanical properties were deteriorated and decreased in OLETF rat. The results showed that bone strength is decreased in OLETF in spite of high body weight.

Abstract: The purpose of this study was to investigate the contribution of the microstructural properties of trabecular bone in predicting its elastic modulus in the intertrochanteric region. A total of 15 trabecular bone core specimens were obtained from the proximal femurs of patients undergoing total hip arthroplasty. The micro-computed tomography (micro-CT) was used to scan each specimen to obtain micro-morphology. Microstructural parameters were directly calculated using software. Micro-CT images were converted to micro-finite element model using meshing technique, and then micro-finite element analysis (FEA) was performed to assess the mechanical property (Young’s modulus) of trabecular bone. The results showed that the ability to explain this variance of Young’s modulus is improved by combining the structural indices with each other. It suggested that assessment of bone microarchitecture should be added as regards detection of osteoporosis and evaluation of the efficacy of drug treatments for osteoporosis.