Papers by Keyword: Femur

Abstract: Radiation is essential in medical diagnostics but poses health risks, necessitating effective shielding to minimize exposure. This research evaluates cassava starch-based bioplastic-lead as an alternative radiation shielding material in femur radiography using Anteroposterior (AP) and Lateral projections with portrait and diagonal detector positions. Bioplastic samples with a 45:55 ratio of cassava starch and lead acetate were tested on a preserved human femur with and without shielding. Image processing using the Gaussian High Pass Filter (GHPF) method and analysis with Contrast to Noise Ratio (CNR) and Peak Signal to Noise Ratio (PSNR) were conducted to assess image quality. Results showed that lead bioplastics achieved 49.4% radiation absorption, with optimal anatomical visualization at cut-off frequencies of 5 and 10, while higher frequencies led to image distortions resembling osteoporosis. The best CNR and PSNR values confirmed improved image contrast while maintaining diagnostic accuracy. This research demonstrates that lead bioplastic effectively reduces radiation dose while preserving image quality, making it a promising alternative shielding material for medical imaging applications

Abstract: The recovery of a fractured femur using the plate and screw internal fixation. The plate internal fixation is made of metal has good mechanical strength, but causes allergic reactions, secondary surgery, stress shielding and high costs. Evaluation of the lack of metal, now developed biodegradable polymers use Polylactide (PLA) and Poly ɛ-caprolactone (PCL). The advantages of PLA and PCL materi-als can control the rate of degradation and increase mechanical strength. Manufac-turing processes of the plate fixation internal using cold isotactic pressing. Inde-pendent variable on the PLA/PCL blends from 90/10, 80/20, 70/30, and 60/40 wt% and tested for FTIR, XRD, SEM, density and porosity. Result from adding PCL make the degree of crystallinity is decreased significantly. The formation of semi-crystalline the with peak width smaller and the crystal size bigger in the 60PLA sample. PLA/PCL blends largely formed bonding and some immiscibility in the form of small flakes and cavities after the addition of PCL content. Large cavities reduce density and increase porosity which can affect mechanical proper-ties. 90PLA sample has high density and low porosity of 1,186 g/cm3 and 4% porosity, respectively.

Abstract: Magnesium alloys have shown potential as biodegradable metallic materials for oral and maxillofacial surgery applications due to their degradability. Biodegradable magnesium are advantageous over existing biodegradable materials such as polymers, ceramics and bioactive glasses in load-bearing applications where sufficient strength and Young’s modulus close to that of the bone are required.

Abstract: LC-DCP (limited contact—dynamic compression plate) is the preferred plate in internal fixation. A new LC-DCP fixed with the femur was designed. Its strength was investigated with finite element method during stair climbing. Also, stress shielding and strength of femur fixed with TC4 (Ti6Al4V) compression plate was analyzed for different load mode during stair climbing. Simulated results demonstrated that compression plate’s design was reasonable, and it was not obvious to eliminate femoral stress shielding through adding preload on the screws. Also the analytical methods of stress shielding for femur fracture, established in the work, can be widely applied to stress shielding analysis of other bone fracture.

Abstract: Total hip replacement (THR) is a flourishing orthopaedic surgery which generating billion of dollars of revenue. The cost associated with the fabrication of implants has been increasing year by year and this phenomenon has burdened the patient with extra charges. Consequently, this study will focus on designing an accurate implant via implementing the reverse engineering of three dimensional morphological study based on a particular population. By using the finite element analysis, this study will assist to predict the outcome and could become a useful tool for pre-clinical testing of newly designed implant. A prototype is then fabricated using 316L stainless steel by applying investment casting techniques which reduce manufacturing cost without jeopardizing implant quality. The finite element analysis showed the maximum von Mises stress was 66.88 MPa proximally with a safety factor of 2.39 against endosteal fracture, and micromotion was 4.73 μm which promotes osseointegration. This method offers a fabrication process of cementless femoral stems with lower cost, subsequently helping patients, particularly those from non developed countries.

Abstract: Plates are most commonly used fixation devices on treatment of femoral fracture, Hwoever, due to the unique mechanical properties and the strong bearing capacity of the femur, the cases of plate broken are at the top of the body skeleton. With the femur’s healing, the stress on the femur and plate is in the process of dynamic transfer. Therefor, healing factors of femur should be considered to more fully describe the stress conditions, on femoral fracture fixation study. This paper study on titanium plate fixation of femoral fracture, analyzed the stress of the femur and plate in different healing period of the femur under different loads.

Abstract: This paper deals with the difference of finite element analysis of results between distinguishing bone materials modeling and single bone material modeling. The computed tomography (CT) data was used to build the model that can distinguish cortical bone, cancellous bone of the femur model, together with the plates could be used to set up internal fixation system and do the finite element analysis. The results indicated that the distributions of stress and strain were basically the same, so were the location of the maximum stress and strain. While, except under the axial loads the value of maximum stress and the value of maximum strain showed significant differences. Finally, study reached the conclusion that under the axial loads there were no significant difference between the two methods, thus the single bone material model could be used for easier computing, while, under the other 4 consequences paper recommended distinguishing bone material method for more practical results.

Abstract: The relationship between morphological parameter and different type of loading orientation on elastic behavior and yielding of trabecular may provide insight towards osteoporotic bone losses during normal activities. This paper attempts to predict the elastic and failure behavior of different loading modes (tensile and compression) on anatomic sites and morphological indices through finite element (FE) simulation. Specimens extracted from bovine femoral trabecular bone were imaged using micro computed tomography (μCT). Morphological studies were done followed by FE analysis. Results demonstrated differences between yield behaviors on anatomic sites were reflected onto the morphological indices and the type of loading modes. The yield initiated earlier in rod-like than plate-like trabecular in both loading condition but showed different failure behavior in rod-like trabecular with small differences in maximum stress between tensile and compressive. However, in many cases, trabecular models tend to have oblique fracture pattern in all anatomic sites. Through these findings, improved prediction of elastic properties and yield behavior by computational means provide insight in the development of bone substitute material depending on the anatomic site as well as in osteoporotic bone pathological treatment to monitor losses in trabecular struts.

Abstract: This paper will take five male patients who performed a double-bundle anterior cruciate ligament (ACL) reconstruction to do finite element analysis and compare the stress distributions with each other. In order to lead this paper to reality, a model of the original bone tunnel according to CT is created and transformed into a finite-element model based on the reverse engineering method. The double-bundle ACL graft in the bone tunnel simulates the interference screw which screwed the ACL under the limit of friction and fix of contact. The dynamic analysis is performed with the femur flexion-extension axis which is under the limit of a fixed rotation angle (100°) and two degrees of freedom of motion in flexion. In the postprocess, the ACL graft is divided into several parts to get the stress distribution which will be easily to discuss the results. The result shows that max stress can be found on the top of the ACL or at the start point of the ACL because of the fixed position of the interference screw. The stress in PL bundle is greater than the stress in AM bundle. The angle of flexion will affect the stress and the stress might be higher at a specific angle.

Abstract: Based on the thermo elasticity theory, the stress of femur prosthesis system was analyzed using finite element method. An evaluation for the selection of prosthetic material was presented after discussing the thermo physical property of material which had an effect on the stress of femur prosthesis system. The results indicate that the interface failure is the primary failure form of the femoral prosthesis system and the interface failure is accelerated for the reason of the thermal effect. So the prosthesis with low coefficient of thermal expansion should be selected which can moderate the interface failure in the certain degree.