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Osteoporotic patients occur frequently fragile fractures, and femoral fractures are the common traumatic injuries in the elderly. Although wires are often used through trials-and-errors for unstable femoral proximal fractures with DHS fixation clinically, there is no efficacy wire fixation technique available due to the lack of biomechanical study. FEM is applied to analyze the stress and strain distribution...
This study investigates the combinations of loading which cause injury to knee joint ligaments. A 3D model of a knee, including bones, cartilage, menisci and ligament bundles was created from magnetic resonance images (MRI). Material properties for bone, cartilage, meniscus and ligament were all determined based on previous published work. The model incorporates a novel approach for accounting for...
The incidence of forearm injuries in the United States is high, with approximately 645,000 people sustaining radius and ulna fractures annually. For forearm fractures where bone alignment remains unaffected, cast immobilization is traditionally prescribed for an average period of 6 weeks to allow fracture union to occur. However, complications such as disuse muscle atrophy and bone demineralization...
To diagnose the osteoporosis accurately, the bone mineral density (BMD) measurements of the vertebral bodies (VBs) are required. In this paper, we propose a new segmentation and registration method in order to assist the BMD measurements and fracture analysis (FA) accurately. In this experiment, image appearance and shape information of VBs are used. Our shape model is required to be registered to...
Osteoporosis is a major health problem affecting roughly 55% of the U.S. population 50 years of age or older. Current methods to detect osteoporosis or assess bone fracture risk involve a bone mineral density (BMD) exam generally using x-ray techniques - primarily dual x-ray absorptiometry (DXA). While this technique provides a measure of the bone mass, it does not offer any insight into bone quality,...
In fluoroscopic tracking for fractured femur bone fixation, a precise identification of the femoral head provides valuable guidance for positioning the implant instruments such as nails and screws. Noise, occlusions and weak edges challenge the task of automatically segmenting the femoral head. In this paper, a fast and fully automated method to precisely delineate the femoral head in fluoroscopic...
Micro-Mechanical properties of bone have been extensively observed in this study. It has also been attempted to correlate it with the microstructural aspects. The load deformation pattern of human cortical bone (both male and female) under uniaxial compressive and tensile loading was studied. The density and porosity of the whole femur as well as different parts of it was also studied. Microstructure...
Nanocomposites are recently known to be among the most successful materials in biomedical applications. In this work we sought to fabricate fibrous scaffolds which can mimic the extra cellular matrix of cartilaginous connective tissue not only to a structural extent but with a mechanical and biological analogy. Poly(3-hydroxybutyrate) (P3HB) matrices were reinforced with 5, 10 and 15 %wt hydroxyapatite...
This article established the pelvis models with aeolotropic material property, and made modeling and mechanical analysis of the acetabular transverse fracture models treated with different internal fixation methods. The mechanical indexes we interested in are as follows, the maximal displacement, the maximum equivalent stress and the maximum stress around the fracture line. Through the compare of...
Relationship between osteoporosis and failure mechanism can be assessed through quantitative bone quality and clinical studies. Characterization and functional studies in this area is vital to identify patients at risk of bone fractures. Identification of elastic bone modulus can be done using several methods including mechanical testing and correlations between microarchitectural parameters. In this...
One of the most common spinal fractures is thoracolumbar spine fracture and in this area burst fracture contributed approximately 10%-20% of such spinal problems. The purpose of this study is to investigate biomechanical effects of anterior decompression and posterior instrumentation and evaluate the role of short-segment pedicle screw instrument in order to preservation of adequate spine stability...
One of the basic principles for internal fixation is the achievement of stable construct for proper bone healing. Locking compression plate (LCP) achieved it through locking screws that create a fixed-angle construct providing angular stability. The plate and screws combination to construct a stable fixation depends on factors such as the type of fracture and surgical preference. The optimum combination...
The main purpose of this research was to predict the site and type of fracture in the tibial shaft under transversal and torsional impacts, using FEA. In this research, tibia was supposed to act as an elastic cortical shell with transversely isotropic symmetry. Effects of the spongy bone were ignored because of its much lower stiffness than the cortical shell. Results of stress contours were in agreement...
In order to understand the effects of bone density on the mechanical properties of femoral neck and improve the effects of treatment for femoral neck fractures, this paper presents a novel method of simulating the bone density changes among individuals. In this method we adjusted the experiential equations between the bone density and gray value and then obtained the mathematical model of the change...
Objective: The purpose of this study was to evaluate the mechanical behavior of three different types of implants used in the osteosynthesis of comminuted humeral shaft fractures. Materials and methods: We used 16 Sawbones® composite synthetic bones. We created a medial third osteotomy and we removed a 38mm thick fragment. We instrumented the fractures with 3 types of implants: an intramedulary nail,...
The present paper, based on a bio-engineering application, intends to apply the mathematical model in the treatment and diagnosis of tibial plateau fractures. Therefore, we focused on the method of finite elements (MFE), which is the general method of solving differential equations with partial derivates that describe physical phenomena. The thus carried out mathematical simulation has revealed the...
This experimental study investigated the hypothesis that low dose irradiation can enhance fracture healing and mineralization. Standardized transverse femur fractures were created and intramedullary fixed with open technique to forty young adult, male Sprague-Dawley rats and randomized to RT (treatment with 1 Gy) and C (controls, sham treatment) groups. At third and sixth week after fracture, high...
The diagnosis of osteoporosis and the prevention of femur fractures is a major challenge for our society. However, the diagnosis performed in clinical routine from Dual Energy X-ray Absorptiometry (DXA) images is limited. This paper proposes a 3D reconstruction method of both the shape and the Bone Mineral Density (BMD) distribution of the proximal femur from routinely used DXA images. The reconstruction...
Medial tibial stress syndrome (MTSS) is pain or discomfort in the leg from repetitive running on hard surfaces or forcible excessive use of foot flexors. Early diagnosis is extremely critical for proper treatment and reduces complications. Quantitative ultrasound (QUS) has been widely used to assess bone quality non-invasively, it is also radiation free, repeatable, safe, relatively accurate, and...
Bone loss in the spine due to estrogen withdrawal following menopause leads to reduced mechanical strength and ultimately fracture in women. Ovariectomized mice may serve as an appropriate model for Type II osteoporosis, but have not been fully characterized. This study relates whole bone mechanical properties to morphological changes in mouse vertebrae following estrogen withdrawal. The development...
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