Papers by Keyword: Bone Fracture

Abstract: This study explored eggshells as an eco-friendly and cost-effective material for synthesizing hydroxyapatite. The phase compositions and morphological structure of polylactic acid composite with and without co-doped hydroxyapatite addition via a melt blending approach were evaluated. Furthermore, the biodegradation profile of the polylactic acid composite in phosphate buffer solution was studied. The concentrations of PLA/HAp, PLA/7.5MgO-7.5ZnO, and PLA/12.5MgO-2.5ZnO samples, respectively, were examined in this study. The results of morphological evaluation showed a well-distributed irregular spherical phase of hydroxyapatite. Meanwhile, the co-doped hydroxyapatite phases have variations in sizes and shapes. The polylactic acid composites showed fractured, rough, and honeycomb surfaces with interconnected pores suitable for cell propagation and enhancement, and the elemental composition proved precipitation of apatite formation. Characteristics of absorption bands of the hydroxyapatite, magnesium, zinc, and polylactic acid were present, respectively. The XRD spectra confirmed the presence of crystalline and semi-crystalline structures with percent crystallinity of 48.57%, 56.64%, and 60.08%, respectively. Meanwhile, the addition of the co-doped hydroxyapatite results in shifts in the 2θ angles of the crystal phases. The biodegradation study revealed the beneficial role of reinforcing polylactic acid composite with biogenic hydroxyapatite and hybrid doped hydroxyapatite as fillers and their synergetic effect with the pH of 7.08±0.21, 6.63±0.46, & 7.28±0.44, the porosity of 52.26±7.29, 48.57±6.74, & 43.72±5.07 %, and the degradation rate (weight loss) of 51.83±7.03, 48.16±6.85, & 43.66±5.46, respectively. Findings revealed that the current study aligns with the sustainable biodegradable composite used in bone tissue repair and hence contributed towards sustainable material without polluting the environment.

Abstract: This study aims to present the preliminary studies related to the evaluation of the in vivo biocompatibility using the rat model of bioresorbable composite materials type collagen-tricalciumphophate and colagen-tricalcium phosphate-magnesium for potentially medical application in trauma surgery. These biomaterials could be used as short-term structural support for bone tissue defects and can be reabsorbed into the body after healing are being sought. For in-vivo evaluation of bioresorbable materials on 2 groups of twenty Wistar and brown Norway rats for a period of 18 months. We simulated tissue defects in different anatomical areas of the animals and these two types of biomaterials were implanted. The animals were evaluated periodically with clinical exams, laboratory tests (blood tests, histopatological tests, radiological control) and anatomical dissection for macroscopic examination of the tissues. After different times (3, 6 and18 months) of implantation we sacrificed the animals. We observed the resorbtion rate of the biomaterials into the tissues in conjunction with tissue regeneration. We also note the inflammatory response and foreign body reactions into the adjacent tissue, using histopathological examinations. Due to the reaction of the materials in contact with the bone narrow a layer of magnesium calcium phosphate was formed which contributes to the local tissue healing. Our preliminary investigation results on these materials demonstrate that all the implanted materials were absorbed in vivo without any pathological changes in the rat body. Other future researches will be made in order to validate these biomaterials as orthopedic biomaterials useful in bone defects regeneration.

Abstract: This paper investigates a design optimization for "Bone Plate System" which can directly fix human bones fractured. The active trauma system consists of several shaped bone plates and implant screws for fixation of fractured human bones with various manual instruments allowing to handle them. The material corresponds to titanium because it was well known as harmless material when being inserted into human body. This system has to be suitably rigid as well as manually bended in orthopedic surgery operations. Then bone plates have to be designed with suitable shapes. In order to verify whether bone plates were well designed, a series of bending tests. However optimized shapes of bone plates have to be determined before unnecessary a number of bending tests. For this purpose FEM(Finite Elements Method) was applied during design process which allows us to investigate the bending strengths of bone plates. Based on FEM results, dimensions of bone plates were optimized in order to be suitably rigid without actual bending tests.

Abstract: The Extended Finite Element Method (XFEM), has become a well-known tool to simulate crack propagation problems using non-structured meshes avoiding the remeshing process usually needed in this type of problems and allowing the inclusion of appropriate shape functions that reflect the asymptotic displacement field, near the crack tip, via a partition of unity fracture approach. However, in this kind of numerical applications, all the variables involved have been considered as deterministic (defined by a single given value), despite the well-known uncertainty associated to many of them (external loads, geometry and material properties, among others). The combination of the XFEM and probabilistic techniques is here proposed and formulated allowing treating fracture mechanics problems from a probabilistic point of view. We present the implementation of this probabilistic extended finite element method and apply it to the prediction of the appearance and propagation of a femur’s neck fracture under probabilistic loads.