Biomechanical Analysis of Diffuse Idiopathic Skeletal Hyperostosis and Osteoporosis: Vertebral Fracture Risk Evaluation Using Finite Element Modeling with Clinical and Micro-CT Data in an Elderly Donor

Biomechanical analysis of spinal structures is crucial in the evaluation of injuries, the risk of fracture, and age-related changes. Osteoporotic vertebrae are very fragile and therefore constitute a serious risk, especially in the elderly. At present, clinically relevant decision making in fracture risk assessment is predicated upon finite element analysis (FEA), which utilizes high-resolution computed tomography (CT) scans from clinical practice alongside micro-CT scans from laboratory settings. Of particular interest is the utilization of cortical vertebral body thicknesses, as meticulously measured via micro-CT. The data from a body donation over 80 years old with diffuse idiopathic skeletal hyperostosis (DISH) and osteoporosis (OP) were utilized through FEA to evaluate stresses in cortical and trabecular bone and to predict the stiffness and deformability of the examined vertebral bodies. The investigation revealed a higher density of cortical and cancellous bone in vertebrae affected by DISH. Cortical density was highest in the thoracic section (median 188 µm), while cancellous bone density was 222 HU in the cervical vertebrae. The load on cortical bone increased as we progressed towards the lumbar spine; however, it remained quite constant in cancellous bone. Despite a low bone density, we registered no fractures in vertebrae. The data showed that DISH increased the thickness of the cortical bone and the density of the cancellous bone. The combination of increased cortical and cancellous bone density might reduce the risk of fracture in patients with low bone density. These conclusions emphasize the significance of biomechanical properties in the assessment of fracture risk and have important implications for clinical practice, particularly in relation to the prevention of vertebral fractures in osteoporotic patients with DISH.