Koji Totoribe

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Biomechanical analyses under compression only, and for a combination of flexion, extension, rotation, and lateral bending were performed to evaluate the stress of the interarticular portion of the lumbar vertebra using a nonlinear three-dimensional finite element method. A detailed three-dimensional L4-L5 motion segment model was developed that took into(More)
We established a three-dimensional finite element method (FEM) model of the 4th and 5th vertebrae, using computed tomography (CT) images (2-mm slice thickness) of a healthy 29-year-old man. Because of the lack of specific data regarding the material characteristics of the nucleus pulposus of intervertebral discs, we used intradiscal pressure in the nucleus(More)
The risk of accelerating the degeneration of adjacent disc levels after lumbar spinal fusion is a controversial issue. A finite element model consisting of L1 to L5 lumbar spines was used to assess the effect on adjacent disc level after lumbar spinal fusion. We compared intact, L4/5 posterior interbody fusion (PLF), and L4/5 posterior lumbar interbody(More)
The purpose of this study was to analyze the effect of lumbar spine fusion on the superior adjacent intervertebral disk in the context of disk degeneration, using a nonlinear three-dimensional finite element method. Detailed L3-L5 motion segment models of normal and degenerated intervertebral disks were developed. In fusion models, L4-L5 was fixed by either(More)
BACKGROUND Finite element analysis (FEA) has been applied for the biomechanical analysis of acetabular dysplasia, but not for biomechanical studies of periacetabular osteotomy (PAO) or those performing analysis taking into consideration the severity of acetabular dysplasia. This study aimed to perform biomechanical evaluation of changes in stress(More)
The cervical spinal cord is at a great risk for injury during traumatic accidents occurring within people of relatively young age. Spinal cord injury can not be easily characterized clinically nor through in vitro testing. An understanding of cervical spinal cord deformation is important for defining an injury threshold of the spinal cord. Therefore, an(More)
Biomechanical analyses under compressive load, flexion, and extension torque were performed, using a nonlinear three-dimensional finite element method, to evaluate stability in posterolateral fusion. Effects of facet fusion and disc denucleation on posterolateral fusion were also examined. Using an initially prepared L4-5 motion segment model, we prepared a(More)
Biomechanical analyses under compression, flexion, and extension loading were performed to evaluate the stability of interbody, posterolateral, posterior, and facet fusions using a nonlinear three-dimensional finite element method. The effects of facet fusion on other lumbar fusions were also examined. A three-dimensional L4-L5 motion segment model was(More)
Autologous bone grafts for posterolateral lumbar fusion are harvested from the iliac crests. Recently, several alternatives to autologous bone have been evaluated (such as graft substitutes, graft extenders, or both) with variable results. However, no clinical long-term studies have validated the efficacy of these techniques in posterolateral lumbar fusion.(More)
Simple methods for quantitative evaluations of individual motor performance are crucial for the early detection of motor deterioration. Sit-to-stand movement from a chair is a mechanically demanding component of activities of daily living. Here, we developed a novel method using the ground reaction force and center of pressure measured from the Nintendo Wii(More)